paragon ceramic kiln instruction & service manual...2 monitor the kiln during operation!...

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Paragon Ceramic KilnInstruction & Service Manual

The FirstFiring—See page 29

2 Monitor the kiln during operation!

INTRODUCTIONThank you for purchasing a Paragon kiln. We are confident that the kiln will give you many years of relaxation andcreative enjoyment. Before using your kiln, read the manuals that came with it. They will save you many hours as youlearn about your kiln. The more you know about your kiln, the more you will enjoy it and the longer it will last.

This manual does not cover the digital controller or the Kiln Sitter and switches. They arecovered in a separate manual included in your instruction packet.

In the instruction packet for your kiln, you should find a copy of “Safe Installation of the Electric Kiln,” “FirebrickMaintenance,” and a manual that covers your kiln’s control system. Please contact the factory if you do not havecopies. You can also find them at www.paragonweb.com. Select “Support” and then “Instruction Manuals” fromthe drop menu. The manuals are listed alphabetically.

At www.paragonweb.com select “Products,” then “Books & DVDs” from the drop menu. The books we recom-mend will enhance your kiln experience. You can also email or phone us with questions. We are glad to help.

At www.paragonweb.com you will find online videos for many of the procedures shown in this manual. As you readeach section, you can go online to watch an actual demonstration on your computer.

Even though your Paragon kiln may be designed to shut off automatically, check the kilnbefore the expected shut-off time. The warranty on your kiln does not cover damage fromoverfiring, regardless of the circumstances. It is the operator’s responsibility to make sure thekiln turns off when the firing is completed. Never leave your kiln unattended near the end ofthe firing.

Check your new kiln frequently during the first few firings and note the color changeinside the kiln. After awhile you can learn to estimate, with considerable accuracy, whenthe kiln is about to shut off just by observing the color.

We are accustomed to using products that stay new looking for years—cars, furniture,cameras. But kilns are different. The high temperatures they reach generate tremendousstresses. Since the insulating firebricks expand and contract with each firing, hairlinecracks will appear in the bricks while the kiln is cold—even in a new kiln. Do not be con-cerned with these. They are normal. The cracks close tightly when the heated bricksexpand. The cracks function as expansion joints and will not affect the firing. Though theinsulating firebrick is fragile enough to carve with a fingernail, it is a miracle of physicsand when properly maintained can survive for many years.

Do not be concerned with the light that appears around the edge of the lid or door. As long as the lid/door is closed allthe way, there is little heat loss. Discolored paint is also inevitable and doesn’t affect firing results.

Do not be concerned with the clicking sound that the kiln makes during operation. Digital kilns contain relays,which send power to the elements. The relays click as they cycle on and off to maintain the correct temperature. Andthe infinite switches of manual kilns make a clicking noise too. You will also hear theelements hum. This is only the sound of element coils vibrating in their brick grooves.Once you become familiar with these sounds, you may find them a reassuring indica-tion that the kiln is firing normally.

If you call us about your kiln, please have the model number, part number (P/N), andvoltage from the kiln’s electrical data plate handy. (The plate is on the side of theswitch box.) Write that information here for quick reference:

P/N____________________ SN______________ Model______________ Volts____________

Thank you again for purchasing a Paragon kiln. We wish you many years of relaxation and creative enjoyment withyour new purchase! You will find that owning a kiln will give you the freedom to experiment with new ideas and tofire any time you want. Owning a kiln will take your ceramic skills to a new and exciting level.

©2008, by Paragon Industries, L.P. IM-104/11-08

Please do not be concernedwith the line of light that appearsaround the lid. It is normal.

Fire only in a well ventilated area! 3

CONTENTSIntroduction . . . . . . . . . . . . . . . . . . . . . . . . . 2

Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Important Safety Rules . . . . . . . . . . . . . . . . 4

Setting Up. . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Setting Up The Stand . . . . . . . . . . . . . . . . . . . . . 6

Attach the Lock-In Lid Support . . . . . . . . . . . . . . 6

Where to Locate Your Kiln . . . . . . . . . . . . . . . . . 6

Seating the Elements . . . . . . . . . . . . . . . . . . . . . 7

Cleaning the Kiln. . . . . . . . . . . . . . . . . . . . . . . . . 8

The Electric Circuit . . . . . . . . . . . . . . . . . . . 8

Electrical Shutoff . . . . . . . . . . . . . . . . . . . . . . . . . 8

Circuit Breaker Panel . . . . . . . . . . . . . . . . . . . . . 8

Circuit Wire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Voltage Affects Firing Time. . . . . . . . . . . . . . . . . 9

Check the Electrical Installation . . . . . . . . . . . . . 9

Preparing The Kiln . . . . . . . . . . . . . . . . . . . . 9

Kiln Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Monthly Kiln Maintenance . . . . . . . . . . . . . . . . 10

Pyrometric Cones . . . . . . . . . . . . . . . . . . . 11

Cone Numbers . . . . . . . . . . . . . . . . . . . . . . . . . 11

Heat Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Using Cones . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Pyrometric Cone Charts . . . . . . . . . . . . . . . 12, 13

How to Position Cones on the Shelf . . . . . . . . 14

Using Cones in Digital Kilns . . . . . . . . . . . . . . . 15

The Bending of the Cone . . . . . . . . . . . . . . . . . 15

Firing Accessories. . . . . . . . . . . . . . . . . . . 16

Preparing To Fire The Kiln . . . . . . . . . . . . 17

Vacuuming the Kiln. . . . . . . . . . . . . . . . . . . . . . 17

Drying Greenware. . . . . . . . . . . . . . . . . . . . . . . 18

Shelf Preparation . . . . . . . . . . . . . . . . . . . . . . . 19

Loading The Kiln . . . . . . . . . . . . . . . . . . . . 21

How to Store Kiln Furniture . . . . . . . . . . . . . . . 21

Guidelines for Loading the Kiln . . . . . . . . . . . . 21

Distances Inside the Kiln . . . . . . . . . . . . . . . . . 22

Glazed Ware . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Heat Distribution Inside the Kiln . . . . . . . . . . . . 23

How to Position Posts. . . . . . . . . . . . . . . . . . . . 24

Bead Rods . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Firing Large Ware Across Half Shelves . . . . . . 24

Tile Holders. . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Firing The Kiln . . . . . . . . . . . . . . . . . . . . . . 25

The Stages of Firing . . . . . . . . . . . . . . . . . . . . . 25

When to Speed Up the Firing . . . . . . . . . . . . . . 25

Venting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

The Basics of Firing . . . . . . . . . . . . . . . . . . . . . 28

The First Firing in Your New Kiln . . . . . . . . . . . 29

Loading and Firing Low-Fire Greenware . . . . . 30

Loading and Firing Low-Fire Glaze . . . . . . . . . 30

Loading and Firing Overglaze . . . . . . . . . . . . . 31

Loading and Firing Ceramic and Glass Decals 32

Loading and Firing Porcelain Greenware . . . . 32

Loading and Firing Porcelain Glaze . . . . . . . . . 33

Loading and Firing StonewareGreenware or Glaze . . . . . . . . . . . . . . . . . . . . . 33

Imperfections. . . . . . . . . . . . . . . . . . . . . . . 34

General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Bisque . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Glaze . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Underglaze . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Overglaze . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Porcelain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Kiln Maintenance . . . . . . . . . . . . . . . . . . . . 36

Note: Whenever you turn off the circuit breakerto your kiln, tape the breaker box door shutand leave a note saying, “WORKING ONKILN. BREAKER OFF.”

How to Open the Switch Box . . . . . . . . . . . . . . 36

Preventive MaintenanceInside the Switch Box . . . . . . . . . . . . . . . . . . . . 37

Element Maintenance . . . . . . . . . . . . . . . . . . . . 37

Firebrick Maintenance . . . . . . . . . . . . . . . . . . . 43

Tightening the Lid Band . . . . . . . . . . . . . . . . . . 45

Adding a Steel Base Plate . . . . . . . . . . . . . . . . 45

Replacing the Steel Base Plate andTurning Over the Bottom . . . . . . . . . . . . . . . . . 45

Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

Index . . . . . . . . . . . . . . . . . . . . . . Back Cover

“Pottery, as you know, is frustrating. But wecould not fully enjoy success if we did not experi-ence failure. The whole experience is pro-found.”

—Steve Burtt

SAFETYIMPORTANT

Read each page of this manual in detailbefore you install or operate your kiln.Warranty does not cover damagecaused by failure to follow instructions.

Note: Experienced kiln operators keep a smalltimer with them as a reminder that the kiln is fir-ing. You could set thealarm on a digital wrist-watch for the estimatedfiring time less 20 min-utes. When the alarmsounds, go to the firingroom to check the kiln.Do not leave the kiln un-attended, especiallynear the estimatedshutoff time.

FOOD-SAFE GLAZES

Some glazes may not be designed forsurfaces that will be in contact with foodor drink. When you make food or drinkcontainers, select a glaze that has beenformulated, tested, and labeled asapproved for surfaces that will be incontact with food or drink. Follow theglaze manufacturer's instructionsexactly, without any variations. Havecustom glazes tested for food safety by alab such as Alfred Analytical Laboratory.You can learn more about glaze safety inMastering Cone 6 Glazes, by JohnHesselberth and Ron Roy.

Insurance CompaniesIf your insurance company ever inspects your kiln

room, tell the inspector that you follow the safety and in-stallation guidelines shown next. What insurance compa-nies want to see:■ Fire extinguishers and smoke detectors.

■ An electrical shut-off near the kiln (not needed for 120volt models).

■ You have removed combustibles from the kiln room.

■ A licensed electrician installed the circuit.

Important Safety RulesFollowing these safety pointers will add little extra

time to your daily routine. There is little danger of seriousburn from accidental contact if you exercise the samecaution you would use with an electric iron.● Place the kiln on the stand recommended by Para-

gon. When a kiln is safety tested, the lab fires the kilnon the stand designed for it. Cinder blocks or brickscan inhibit the flow of air under the kiln. They canalso change the kiln’s heating characteristics.

● Place the kiln on a non-combustible surface.

● Do not install closer than 12" from any wall or com-bustible surface.

● Fire only in a well ventilated, covered, and protectedarea.

● Do not open the lid until kiln has cooled to roomtemperature and all switches are off.

● Dangerous voltage: do not touch the heating ele-ments with anything.

● Disconnect kiln before servicing.

● Do not leave kiln unattended while firing. Do notleave a kiln turned on at yourstudio while you are at homesleeping.

● Wear firing safety glasseswhen looking into a hot kiln.

● Unplug the kiln, or turn offthe electrical shut-off box orcircuit breaker when thekiln is not in use, especiallyif you are concerned thatsomeone could turn it onwhile you are away.

● Keep the kiln lid or doorclosed when the kiln is not inuse. This keeps dust out ofthe kiln. Also, should some-one turn on the kiln while you are away, the closed lidwill keep the heat safely inside the firing chamber.

● Never place anything on the kiln lid, even when thekiln is idle. If people become accustomed to placingpapers and other objects on the kiln, they may forgetand do that while the kiln is firing.

● Remove all tripping hazards from around the kiln.Keep the kiln’s supply cord out of traffic areas.

● Do not let the cord touch the side of the kiln; it be-comes hot enough to damage the cord.

● Avoid using extension cords.


“Centering the clay has a way of putting meinto that altered state where time doesn’t hap-pen.”

—Millie Carpenter

● Wear gloves when youload and unload yourkiln. The gloves shouldbe thick enough to pro-tect you from glazeshards and bits of pyro-metric cones that havestuck to shelves, sharpedges of broken ware,and sharp stilt marks onthe bottom of glazedware. Razor-sharp glazefragments can be sosmall that they are difficult to see.

● Do not remove the ware from the kiln until the kilnhas cooled to room temperature. It is possible forthermal shock to break hot ceramic pieces. Thesharp edges of broken ware can injure hands.

● After firing glazed ware in your kiln, examine theshelves for glaze particles. Sharp slivers of glazestuck to the shelf can cut hands. Before rubbing ahand over a shelf, be sure the shelf is free of glazeshards.

● Fire only approved materials purchased from aknowledgeable supplier. Do not fire marbles, piecesof concrete, rocks, and other objects. Rapid heatingto high temperature can cause violent reactions inmany materials.

● Avoid firing toxic materials such as moth balls insidethe kiln. Moth balls create toxic fumes inside a kilnand can even explode.

● Never fire tempered glass inside a kiln. It could ex-plode.

● Greenware, which is unfiredclay, must be bone dry be-fore firing. Moist greenwarecan explode inside the kiln,damaging the ware and theki ln. Place a piece ofgreenware against the insideof your wrist. If it feels cool,it is too wet to fire.

● Do not fire cracked shelves. They can break duringfiring, damaging the ware inside the kiln.

● Store kiln shelves in a dry area. Moist shelves can ex-plode inside a kiln.

● If you smell burning plastic, turn the kiln off. Exam-ine the wall outlet and supply cord for signs of burn-ing.

● As the kiln fires, it is a good habit to place your handon the kiln’s power cord to check the temperature. Itis okay if the cord is slightly warm, but it should

never feel hot. Make sure the plug is pushed all theway into the receptacle.

● Never place extra insulation around the kiln in an at-tempt to conserve energy. The extra insulation cancause the switch box wiring to over-heat and thesteel case to warp.

● Do not wear loose-fitting clothing around a hot kiln.

● Remove flammable materials from the kiln room. Ifyou fire a kiln in the garage, park your car outside.Remove the lawn mower, gasoline, and other flam-mable materials. Keep packing materials such asshredded newspapers out of the kiln room.

● Keep unsupervised children away.

● Keep a Class C fire extinguisher and a smoke alarmin the kiln room. Mount the extinguisher near thedoor to the room.

● Do not breathe brick dust, kiln wash, or kiln repaircement. Prolonged exposure may cause lung injury.Vacuum the kiln with a HEPA filtered vacuumcleaner or a central vacuum that takes the dust out-side.

● Only vitrified ware should be used in a microwaveoven. (Vitrified clay has been fired to a point wherethe particles become glass-like and no longer absorbwater.) Non-vitrified clay such as earthenware isgenerally not suitable for microwave use, becausethe clay absorbs water. The water in the pores of theclay can expand rapidly enough in a microwave tocause the ware to crack or even explode. Ware thathas been decorated with metallic glazes should notbe used in a microwave oven.

● Whenever you turn off the circuit breaker to yourkiln, tape the breaker box door shut and leave a notesaying, “WORKING ON KILN. BREAKER OFF.”


How to Avoid an Over-Fire

Suggestions by Mel Jacobson, Potter

1 Use an alarm clock. I use the old wind-upkind with a loud ringer. Set it for a certaintime, and make sure you follow the ring.Place a small battery-operated oven timer inyour pocket if you need extra reminders.

2 Get a large bulldog clip and paint KILN inred. Clip it to your jacket, or hang it from adoorknob. Or place a sign where you hangyour apron: KILN ON.

3 When I was a high school teacher, I had thejanitor turn off the master breaker to the kilnevery night at 8. No kiln would ever be onpast 7, ever, anyway.


SETTING UPSetting Up The Stand

Operate your Paragon kiln only on the stand provided.(Sometimes people buy used kilns that are missing theoriginal stand and place the kiln on cinder blocks orbricks. This is not a good idea, because bricks may inhibitthe flow of air under the kiln. Cinder blocks could alsochange the kiln’s heating characteristics.)

We recommend that you wear tight-fitting gloves suchas mechanic’s gloves while assembling the stand.

You will find 2 shelves, 2 side frames, and a bag of nutsand screws in the stand kit. The shelf with the hole in thecenter is a top shelf. The solid shelf goes on the bottom.The side frames have bottom mounting holes for casters.

1 Insert a short tabfrom the solidshelf into a sideframe. The tabgoes on the out-side of the sideframe.

2 Repeat Step 1 forthe other sideframe.

3 Lay the top shelf(the one with thehole in the center)over the sideframes. The shorttabs go on the out-side of the sideframes. The longtabs go on the in-side of the sideframes.

4 Insert the screwsand nuts.

5 Install the casters. You can leave off the casters ifyou want to make the stand shorter.

Caution: You MUST lock the casters beforeplacing the kiln on the stand.

Install the Orton Vent CupSkip this step if your kiln does not have an Orton Vent.

1 Attach the hose to the vent cup with the clampthat came with the Orton Vent.

2 Slide the vent cup up inside the stand and into theflange supports in the top shelf. Rotate the ventcup a little as you slide it into the flange supports.

3 Place the gasket that came with the vent over thevent cup.

Attach theLock-In LidSupport

Models with the lid support:Connect the lid support to thestud on the side of the kiln.Tighten the lock nut until it issnug.

Where toLocate Your Kiln

In addition to these guidelines, please see “Safe Instal-lation of the Electric Kiln,” a separate publicationshipped with your kiln.■ Plan your firing area near a present electrical outlet or

where a new circuit can easily be installed.

■ Place your kiln in a well-ventilated, covered, and pro-tected area such as the garage, basement, storagebuilding, utility or ceramic hobby room.

Caution: The fumes from ware fired in a kiln cancorrode metal and etch windows. If you are in-stalling your kiln in a living area such as the base-ment or in the garage, it should be vented with amotorized vent. Please see “Safe Installation ofthe Electric Kiln.”

Q Is it okay to place the kiln on a covered porch orin a carport?

A Yes. As long as the kiln is protected from theweather, it can be installed in a roofed-in areawith open sides such as a carport. But especiallyin humid areas, the kiln may rust faster than itwould inside an enclosed building.

■ Do NOT store gasoline, paint, or other flammable liq-uids in the kiln room.

■ Never allow the room temperature of your firing roomto exceed 100 - 110°F. (Room temperature is the tem-perature measured three or more feet away from thekiln.) If necessary, use a fan to move the heat awayfrom the kiln’s switch box.

■ Electrical components such as switches, the digitalcontroller, relays, and wiring last longer when they staycool. The easiest way to lower the temperature of akiln’s switch box is to blow air into the side louverswith a fan. It does not need to be a large fan; one with 4"- 8" diameter blades on low speed is effective. The airshould go in one side of the switch box and out the lou-vers of the other side. Do not allow air to blow into thekiln through the peepholes or lid.

The short bent tab goes on the outsideof the side frames.

Shorttab goeson out-side.

Side frame

The long bent tabs go on the inside ofthe side frames. The short bent tabs goon the outside.

Longtabs goinside.

Shorttabs gooutside.

■ Provide a minimum of 12” clearance between the kilnand the closest wall.

■ Never place the kiln near curtains or other combusti-ble materials such as art room supplies.

■ Position the kiln stand on a level surface that will notbe damaged by heat. We recommend a cement floor.However, a sheet of protective material may be usedunder the stand. Consult your hardware or buildingsupply store for a recommendation.

■ Avoid placing the kiln stand on rubber tile, linoleum orany surface that might tend to mar or discolor whenheated.

■ Place the kiln in an area where it can be easily loadedand unloaded yet out of the way when not in use. Forconvenience in moving the kiln when not in use, con-sider the reinforced, deluxe stand with casters.

■ Keep unsupervised children away from the firing area.

■ Do not allow the kiln’s power supply cord to contactthe side of the kiln. This could burn the cord. Beforeeach firing, check all around the kiln to make surenothing is touching the kiln case.

Cold WeatherIt is okay to store and fire the kiln in an unheated build-

ing during winter. But before operating, raise the tem-perature of the kiln’s switch box to at least 32°F (0°C)with a space heater.

Q What is the difference in the cost to fire a kilnin a warm room compared to firing in a coldroom?

A Room temperature has almost no effect on theelectrical cost of firing a kiln. However, if yourkiln is under a carport that has open sides, pro-tect the kiln from wind. Air blowing against thecase can raise the electrical cost slightly. If youuse a fan to lower the temperature of the switchbox, position the fan so that the air blows into the

switch box louvers but not onto the firing cham-ber case.

Installing the Kiln in anInstitutional Setting

Sometimes maintenance employees are not familiarwith kilns. For this reason you might want to place a signon top of the kiln when the kiln is not in use:

Do not stand on the kiln.Do not move the kiln.

Do not place anything on top.(Reminder: Remove any signs from your kiln before

you fire it.)Place a sign on the door of the kiln room: Kiln is Firing.Every year hold a short kiln orientation session for the

maintenance staff. You could also send the same infor-mation by e-mail to the school principal and the mainte-nance department. Explain the following:

1 The kiln is fragile.

2 During operation, the kiln makes a clicking noise.This is normal.

3 If you use a temperature alarm on your digital kiln,explain the beeping noise. Otherwise it willfrighten students and maintenance people be-cause they will assume that something is wrong.

Seating the ElementsShipping may dislodge the elements of your kiln.

Please perform the kitchen knife test to make sure the el-ements are seated in their grooves.

Kitchen Knife Test

Caution: Always unplug the kiln before touchingan element with anything.

Caution: Touch only a cold element, never a hotone, with a plastic object such as a comb. Plasticwill melt on and ruin a hot element.

Press the ele-ments into theirgrooves by running ablunt kitchen knife,plastic comb, or simi-lar blunt object com-pletely around eachgroove. Do this be-fore the first firing,because it may not beevident to the eyewhether the coil is inits groove.

Note: Don’t force the element into the groovecorners. If the element won’t fit easily, lengthen itwith automotive snap-ring pliers (available fromauto parts stores). Stretch the space between the


Lower the switch box temperature with air movement. This is especiallyuseful during hot summers.

coils just a little wherethe element fits intothe wall brick corners.It should then easilyseat into the corners.

If the element doesn’tlie flat in the bottom of itsgroove, you needn’t beconcerned as long as theelement fits all the wayback into each corner anddoesn’t bulge outside thegroove. In fact, elementswill not lie flat in their ter-minal bricks (right behindswitch box).

Before the kiln is fired,the elements are mallea-ble; there is no danger ofbreaking the elementswhen you bend them. Afterfiring, however, the ele-ments become brittle andmust be reheated if theybulge out of the groove.See “Reseating a BulgingElement,” page 38.

Cleaning the KilnClean your kiln before

firing. Use a a vacuumcleaner (preferably with asoft brush nozzle) to re-move brick dust from in-side the kiln, especiallyfrom the grooves. A dampcloth or damp sponge mayalso be used to gently wipedust from the sidewallsand brick bottom. Cleanthe kiln again wheneveryou notice dust inside.

Note: Vacuum the kiln with a HEPA filtered vac-uum cleaner or a central vacuum that takes thedust outside. Keep the vacuum hose away fromthe controller on digital kilns.

THE ELECTRICCIRCUIT

Please have only a qualified electrician install your kilncircuit in compliance with local codes. If you plan to usean existing circuit, have a qualified electrician check thecircuit and compare the wire and breaker sizes with thoseshown in the Paragon catalog and website. The circuitmust never be used by other appliances while the kiln isfiring.

Electrical ShutoffWe recommend an electrical

shutoff box near the kiln in addi-tion to having a circuit breaker atthe electrical panel. The shutoffbox is a must for direct-wiredkilns, which can’t be unpluggedto disconnect the power. We rec-ommend disconnecting thepower when the kiln is not in use.If you unplug the kiln frequently,the spring tension on the wall outlet may eventuallyweaken. The shutoff box disconnects the power withouthaving to unplug the kiln.

Note: The shutoff box is not needed for 120 voltkilns.

Circuit Breaker PanelInstall the kiln within 25' of the fuse or circuit breaker

panel. For every additional 50' from the panel, increasethe circuit wire size by one gauge.

But do not place the kiln right in front of the electricalpanel. Keep the panel at least 3' - 4' away. Otherwise, thebreakers may trip more easily on a hot day. This is be-cause a circuit breaker is triggered by heat, and a nearbykiln can raise the temperature of the electrical panel.

Note: Do not use the circuit breaker to discon-nect the kiln. Frequently switching the circuitbreaker will weaken it. Instead, use a shutoff boxlocated near the kiln.

Circuit WireUse a circuit wire size large enough for the wall recep-

tacle amperage, even if the kiln amperage is less than thewall receptacle amperage.

WARNING: Changing the cord plug onParagon kilns may void your warranty.

Trying to save money on the circuit installation by us-ing a smaller diameter wire is not cost effective, becausethe thinner wire generates more heat than the thicker


Expanding coils with automotivesnap-ring pliers.

As shown here, new elements donot lie flat in a curved groove.

“What is it about that meditative quiet whenkids are working with clay? I teach 3rd, 4th and5th graders in a very poor neighborhood, andeven the toughest 5th grader will let down his‘cool and tough’ act for clay.”

—Grace Sheese

wire. The heat means wasted electricity and sometimesslightly lower voltage.

Use copper wire. Do not allow an electrician to use alu-minum wire on your new circuit. Aluminum terminalscorrode worse than copper and require greater installa-tion care. Avoid using extension cords.

The Paragon kiln catalog and website show recom-mended breaker and wire sizes for the circuit. (Theserecommendations assume that the circuit is dedicated,which means that it powers only the kiln and no otherappliance.) Local codes supersede our catalog recom-mendations.

You may already have a heavy-amperage circuit conve-niently located where you will keep your kiln. But do notassume that the circuit is the correct size. Clothes dryercircuits are too small for most studio kilns. Even if youhave the correct wall outlet, you should verify that the wireand breaker sizes are also correct.

Voltage Affects Firing TimeVoltage fluctuation can vary the firing time for a given

pyrometric cone from as little as one half to more thantwice the average time. If the voltage is too low, the kilnwill never reach full temperature. This can be correctedonly by having the utility company adjust the voltage.(However, 208 volts cannot be adjusted to 240 volts, andvice versa.)

Check the ElectricalInstallation

Check the receptacle voltage with a voltmeter beforeplugging in your kiln. Measure between the two slotswhere the flat blades onthe plug are inserted.Only a qualified personshould perform this test,because improper use ofa voltmeter can result inshock to the user.

Verify that the safetygrounding wire is prop-erly connected in accor-dance with the NationalElectric Code (or equiv-alent for your country).This can be proven onlyby visual inspection ofthe receptacle wiring.Sometimes circuits havebeen installed by home-owners with limitedelectrical experience.

PREPARINGTHE KILNKiln FeaturesKiln Firebricks

Premium, hand-selected insulating refractory bricksare lightweight, porous, and precision cut to fit tightly andstore heat in the walls, bottom, and lid. The form-fittedjacket snugly holds the bricks together. Because the fire-bricks store heat so efficiently, the cost of electricity to firethe kiln is surprisingly low. Kiln brick is extremely fragileand will chip easily; always handle your kiln and its brickwith care. Never let a shelf bump against the firebrick.Firebrick damage is not covered by warranty.

Note: Allow only trusted people to load and un-load your kiln. Beginners may not understandthat the firebricks are fragile.

The temperature required forceramics is well above the meltingpoint of most metals, and tremen-dous stresses are generated duringthe firing. The insulating fire-bricks expand and contract witheach firing. In time, cracks will ap-pear in the brick while the kiln iscold. This is normal and will not af-fect your kiln’s operation.

Heating ElementsThe heating elements in your Paragon kiln are heavy

duty for long life. All high temperature, heavy duty ele-ments are quite brittle after being heated to a high tem-perature and will break if bent while cold. By heating to adull red glow with a propane torch, an element may bebent safely.

Never allow glaze, glass, silica sand, kiln wash, or otherforeign materials to touch the elements since they willdestroy the element when the kiln is fired.

PeepholesLarge peepholes (view ports),

tapered for a wide view withoutheat loss, are used for observingthe progress of your firing so youcan see when the pyrometric conesbend. Use at least one large coneon the shelf during every fir-ing—even in a digital kiln. Withventing as their secondary func-tion, peepholes allow oxygen to bedrawn into the kiln’s chamber and serve as an escape pas-sage for smoke and water vapor.

When looking through the peepholes, always wear fir-ing safety glasses, which are available from Paragon. They


Checking the voltage of a wall outlet inthe Paragon factory.

protect your eyes from thebright glare of the firing cham-ber and make it easier to seethe cones at high tempera-tures.

Peephole plugs are used tostop air from entering the kiln,not to prevent heat loss. It isbeneficial to have some air en-tering the kiln at all times, so itis not necessary that the plugsfit tightly.

You can leave the peepholeplugs out for some firings. This improves oxygenation in-side the kiln. However, this may cause cold spots in thekiln, especially if there are air drafts in your firing room. Ifyou leave the peephole plugs out, keep ware at least 3"from the peephole. If your ware develops problems fromcool air drafts, such as a glazed piece with a crazed spot,insert the peephole plugs after the kiln reaches 1000°F(537°C), or about half way through the firing. If you use amotorized downdraft Orton Master Vent, keep peepholeplugs inserted and the lid closed all the way for the entirefiring.

Prop-R-Vent

Ceramic pieces release gases and water vapor duringfiring. Venting allows these gases to escape. Paragon’s fallaway Prop-R-Vent is installed on the switch box of mosttop-loading kilns. The prop supports the lid in an openposition during the venting period. The Prop-R-Ventvents the lid in two stages.

To close the lid after venting, lift the lid handle an inchto let the Prop-R-Vent fall. Lower the lid gently; warrantydoes not cover damage to the kiln or the ware due to adropped lid. For lusters and overglazes, engage theProp-R-Vent in its second position for additional venting.Do not rush the cooling of your kiln with theProp-R-Vent. This can damage your ware.

Do not drop the lid. Some people touch the lid handlefor the first time to lower the lid from venting and dropthe lid because the handle is hot. Use a heat-resistantglove or a lid lifter (sold by Paragon) to lower the lid.


Monthly KilnMaintenance

1 Make sure the kiln is centered on the standand that the stand is stable. Check the areaaround the kiln and remove flammable ma-terials that have accumulated.

2 Vacuum the kiln with the soft brush nozzle ofa vacuum. (You can use a hard plastic nozzleas long as you don’t touch the bricks with it.)Remember to vacuum the brick grooves. Ifyou have difficulty removing debris insidethe grooves, use a narrow wand-type vacuumcleaner nozzle being careful not to scrapethe brick walls. (Seepage 17.)

3 Vacuum around andunder the kiln: floor,shelves, and walls.This keeps the kilninterior cleaner andadds life to the op-tion vent motor.

4 Check the kiln washon shelves and kilnbottom for cracksand bare spots in thecoating. Remove anyglaze drips. Reapplykiln wash if needed.(See page 19.)

5 Check the powercord and outlet forheat damage. Hasthe cord touchedthe side of the kiln during firing? This willdamage the cord insulation. Replace thecordset or wall outlet that shows signs of heatdamage.

6 Make sure elements are not bulging out ofthe grooves. Repair if necessary. (See page38.)

7 Kiln Downdraft Vent: Check the vent ductfor leaks. (See page 26.)

8 Digital kilns: Make sure the thermocoupleextends far enough into kiln:

¼" diameter thermocouple: 1" into the kiln1

8" diameter thermocouple: 58" into the kiln

Wear firing safety glasseswhen looking through a peep-hole into a hot kiln.

Leave the lid closed ifyou have a motorizeddowndraft vent.

The Prop-R-Vent in theextended position.

The Prop-R-Vent in thefirst position.

Full-Formed SteelBase

The galvanized steel baseunder the brick bottomstrengthens the kiln. It cov-ers the entire bottom fromedge to edge.

The Lid SupportYour kiln

has either thelock-in lidsupport orthe LiteLidspring coun-ter-balance.Please do notlet unat-tended chil-dren raise thelid. Do not let the lid drop. It isfragile and must be lowered gently.

Keep the kiln lid closed whenthe kiln is not in use. This keepsdust out of the kiln. Also, shouldsomeone turn on the kiln while you are away, the closedlid will keep the heat safely inside the firing chamber.

The LiteLid Support1 Begin raising the lid using

the center lid handle.When the lid feelsweightless, hold a side lidhandle with your otherhand to guide the lid therest of the way up.

2 Do not let go of the side lidhandle until the lidreaches its fully openedposition. Otherwise thelid could slam upward,damaging the firebricksnear the hinge. (Pleasenote: This type of damageis not covered by war-ranty.)

3 Stay clear of the lid whenraising or lowering. Thisis to prevent injury shouldthe lid drop.

Dust-Free Refractory CoatingThe dark coating on the lid, the top rim of firebricks,

and in the peepholes reduces dust and hardens the fire-brick surface for longer life. Though it will lighten afterthe first firing, the coating will last for several years.

PYROMETRICCONES

Ceramists of earlytimes judged when the fir-ing was completed by thecolor of the kiln interiorand the length of firing. In1886, a German ceramistnamed Seger made claycones that bent when theceramic ware received theproper heat work. He posi-tioned the cones on a shelfinside the kiln. By lookingthrough a peephole, he

could see the cones bend and knew when to turn off thekiln. His cones took the guesswork out of firing.

Today we still use Seger’s cones. They are called pyro-metric cones and are small pyramids of clay and mineraloxide that soften and bend when exposed to heat. Theyindicate when your ware has fired to maturity. When con-sulting your dealer with a glaze problem, you should havea bent cone from that firing. The cone will help troubleshoot the problem. The cone lets you compare one firingto the next. Cones are manufactured by the Orton Ce-ramic Foundation and are available from your distributor.

Cone NumbersThe most confusing thing about cones is the way they

are numbered. They are easier to understand when youknow the reason behind the numbers. Pyrometric conesare numbered from 022 through 01 and 1 through 10.Cone 022 matures at the lowest temperature, and 10 ma-tures at the highest.

Seger numbered his original cones from 1 to 20, with 1being the lowest temperature.Later, cones of even lower temper-atures than cone 1 were needed. Toavoid changing all the cone num-bers, the new numbers started with“0” and went from 01 to 022, withhigher numbers getting progres-sively cooler.

To avoid confusion, mentally re-place the “0” with a minus sign.Numbers without the “0” are posi-tive. The higher the positive num-ber, the higher the temperature.

Numbers with the “0” (or a minus sign) are negative.The higher the negative number, the lower the tempera-ture. With this in mind, you can quickly see that cone 5 ishotter than 05.

Note: Store boxes of cones in numerical orderfrom lowest to highest temperature so that you


Do not exert downwardpressure on the lid untilthe lock-in lid support iscompletely disengaged.

The LiteLid spring can pinch fin-gers. Please keep unattendedchildren away from the kiln.

Do not let go of the side lid han-dle until the lid reaches its fullyopened position.

A selection of self-supportingcones. See the cone charts onpages 12 and 13 for a list of conecolors.

will be less likely to inadvertently pick up thewrong box.

The number is stamped on the base of the cone. Thecone number for each material is usually stated on the la-bel by the clay or glaze manufacturer. Your supplier canalso give you the cone number.

Heat WorkCones are rated by temperature. But it is more accu-

rate to think of them as measuring heat work, not temper-ature alone. Heat work is the combined effect of time,temperature, and the atmosphere inside the kiln. Allthese factors affect the maturity of your ware and not justtemperature. For instance, firing to a lower temperaturefor a longer time will produce the same maturity as firingto a higher temperature for a shorter time. The “Tem-perature Equivalents” chart (next column) shows that aself-supporting 05 cone requires a temperature of 1911°Fto bend to 6 o’clock, yet when fired slower, it will bend at1870°F.

During the last 100 - 200 degrees of firing, the firingrate affects the bending temperature of a pyrometriccone. The faster the rate, the higher the temperaturewhen the cone bends. But the firing speed before the last100 - 200 degrees has no influence on the final tempera-ture of the pyrometric cone. The exception is an ex-tremely fast firing that bloats the cone.

Consult your supplier for the recommended firing rateof your clays and glazes. The thicker the clay, the slower itshould be fired. Firing clay is like making cookies in anoven. Heat the cookies fast, and they will be brown on theoutside but still gooey on the inside. Heat the cookiesslowly, and they will be brown all the way through.

Using ConesPlace the cones on a kiln shelf with the ware. As the

cones heat and bend, they form a glassy material that willstick to a bare shelf. Therefore, apply kiln wash to theshelves to prevent sticking. Do not apply kiln wash to thecones. (See page 19 for kiln wash.) The cones slant 8 de-grees from vertical and bend in the direction of the slant.They will not bend accurately if they are slanted at thewrong angle. Position a cone so it will not touch nearbyware as it bends.

Large cones come in ei-ther standard or self-sup-porting. Standard largecones must be mounted in aclay or wire plaque with 2" ofthe cone exposed above thecone holder. Or you canmount large cones in a pat ofclay. The clay should be drybefore firing. To speed dry-ing, make indentions in theclay with the end of a small


°F Temperature Equivalents For OrtonSelf-Supporting Pyrometric Cones

ConeCone Self-Supporting Cones Pre-Fire

Number ColorHeated at: 27° F 108° F 270° F

Per Hour* Per Hour* Per Hour*

022 — 1087 1094 Green

021 — 1112 1143 Fuschia

020 — 1159 1180 Orange

019 1213 1252 1283 Yellow

018 1267 1319 1353 White

017 1301 1360 1405 Pink

016 1368 1422 1465 Light Blue

015 1382 1456 1504 Violet

014 1395 1485 1540 Gray

013 1485 1539 1582 Green

012 1549 1582 1620 Fuschia

011 1575 1607 1641 Orange

010 1636 1657 1679 Dark Red

09 1665 1688 1706 Dark Red

08 1692 1728 1753 Dark Red

07 1764 1789 1809 Dark Red

06 1798 1828 1855 Dark Red

05 1/2 1839 1859 1877 Dark Red

05 1870 1888 1911 Dark Red

04 1915 1945 1971 Dark Red

03 1960 1987 2019 Dark Red

02 1972 2016 2052 Dark Red

01 1999 2046 2080 Dark Red

1 2028 2079 2109 Dark Red

2 2034 2088 2127 Dark Red

3 2039 2106 2138 Dark Red

4 2086 2124 2161 Gray

5 2118 2167 2205 Green

5 1/2 2133 2197 2237 White

6 2165 2232 2269 Fuchsia

7 2194 2262 2295 Orange

8 2212 2280 2320 Yellow

9 2235 2300 2336 White

10 2284 2345 2381 Pink

*Rate of temperature increase during last 90 -120 minutes of firing. Tables by courtesy of the Ed-ward Orton, Jr. Ceramic Foundation.

Standard large cones in clay conepacks.

brush handle after the cone is inserted. Self-supportingcones stand upright without holders. We recommendself-supporting cones; they are easier and faster to usethan standard large cones.

Handle cones carefully. They are fragile because theyare unfired clay. If dropped, they may develop cracks thatcould affect their performance. Age and normal humiditydo not affect the accuracy of cones. Even if a box of conesis 20 years old, you can stilluse them. However, do notuse them if they become wet.

Standard pyrometriccones come in two lengths: 11

8" and 2 ½". The small coneis used in the Kiln Sitter andthe large cone is used on thekiln shelf.

Note: The Kiln Sitter isa mechanical shut-offdevice that is triggeredby the bending of asmall cone. Digital con-trollers do not use thesmall Kiln Sitter cone.

Self-supporting cones are2 3

8" long. They are packaged

as sets of double cones sothat they will be less fragilein shipping. You will need toseparate the cones. Hold thelarge section of the coneswith the thumb and forefin-ger of each hand and twist.They will snap apart.

Check the accuracy ofyour Kiln Sitter or digitalcontroller by placing cones on the shelf. Mount behindeach peephole a large cone of the same number you arefiring to. This is the firing cone. Next to the firing coneplace a large cone of the next lower temperature; this isthe guard cone. For example, if you are firing to cone 05,place large cones 05 and 06 on the shelf behind the peep-holes. We recommend at least one large shelf cone in ev-ery firing.

Place large cones on the shelf at least 3" away from apeephole. This is to avoid cool air drafts.

Always use Paragon firing safety glasses when lookinginto the peepholes. These glasses are specially coated tofilter out the infra-red and ultra-violet light inside a kiln.They also protect your eyes from heat and reduce glare,making the pyrometric cones easier to see.


°C Temperature EquivalentsFor Orton Self-Supporting

Pyrometric ConesCone Self-Supporting Cones Pre-Fire

Number ColorHeated at: 15° C 60° C 150° C

Per Hour* Per Hour* Per Hour*

022 — 586 590 Green

021 — 600 617 Fuschia

020 — 626 638 Orange

019 656 678 695 Yellow

018 686 715 734 White

017 705 738 763 Pink

016 742 772 796 Light Blue

015 750 791 818 Violet

014 757 807 838 Gray

013 807 837 861 Green

012 843 861 882 Fuschia

011 857 875 894 Orange

010 891 903 915 Dark Red

09 907 920 930 Dark Red

08 922 942 956 Dark Red

07 962 976 987 Dark Red

06 981 998 1013 Dark Red

05 1/2 1004 1015 1025 Dark Red

05 1021 1031 1044 Dark Red

04 1046 1063 1077 Dark Red

03 1071 1086 1104 Dark Red

02 1078 1102 1122 Dark Red

01 1093 1119 1138 Dark Red

1 1109 1137 1154 Dark Red

2 1112 1142 1164 Dark Red

3 1115 1152 1170 Dark Red

4 1141 1162 1183 Gray

5 1159 1186 1207 Green

5 1/2 1167 1203 1225 White

6 1185 1222 1243 Fuchsia

7 1201 1239 1257 Orange

8 1211 1249 1271 Yellow

9 1224 1260 1280 White

10 1251 1285 1305 Pink

*Rate of temperature increase during last 90 -120 minutes of firing. Tables by courtesy of the Ed-ward Orton, Jr. Ceramic Foundation.

A self-supporting cone next to asmall Kiln Sitter cone.

Separate the cones with thumbpressure.

How to Position Coneson the Shelf

Position the witness cones so that you can see themthrough a peephole during firing. If the kiln takes longerthan usual to fire, you may wonder if something has gonewrong and the kiln is over-firing. But by seeing the cones,you will know how the firing is actually progressing.

If you follow these guidelines, you should be able to seethe cones even at cone 10:

1 Place the cones 8" - 12" away from a peephole. Po-sitioning them closer makes them difficult to seeand may also subject them to cool air drafts.

Note: Keep cones at least 2" from an element.

2 Have enough spacearound the cones tokeep them fromtouching a piece ofware when they bend.

3 Position cones so thatwhen viewed from thepeephole, they are sil-houetted by an ele-ment on the oppositekiln wall. If the size ofyour ware doesn’t per-

mit placing a shelf at peephole level, use a post toraise the cones.

4 The element that silhouettes the cones should belevel with the lower part of the cone. If the ele-ment is in line with the upper part of the cone,the cone will disappear from view when it bends.

Note: The center ele-ments in some kilnmodels do not glowbrightly even at hightemperatures. In thiscase, position the wit-ness cones level with atop or bottom element.The element mustglow brightly to silhou-ette the cones.

5 If you use the three-cone system, always have thehigher temperature coneon the same side in everyfiring. Otherwise you canlose track of which cone iswhich.

6 Wear kiln firing safetyglasses when viewing thecones through the peep-hole.

Note: You may find it easierto see the cones by holding asmall mirror at a 45° angle infront of the peephole. Youwill still need firing safetyglasses.

Caution: Some ceramists blow into the peepholeto momentarily darken the cone so they can see itbetter. Please do not do this. This can blow brickdust onto the ware and is a safety hazard. Cool airalso changes the temperature at which the conebends.

Caution: Some ceramists coat the witness coneswith red iron oxide to make them easier to see.Avoid this. It changes the temperature at which

the cone bends.


A same cone silhouetted by a heat-ing element at cone 7—2262°F(1239°C).

A cone seen through a peepholewhile the kiln is at room tempera-ture.

Line up the heating element with the lower part of the cones.

The top and bottom elements glowbrighter than the center elements insome kilns.

Wear firing safety glasses when viewing a witness cone.

“Working in my small studiokeeps me sane and happy. I for-get about everything else and amgrateful to do what I do.”

—Heidrun Schmid

Using Cones inDigital Kilns

Although the digital controllers do not need cones tooperate, we recommend them anyway. Place at least oneself-supporting cone on a shelf behind a peephole in ev-ery firing.

If the bending of the witness cones varies slightly fromfiring to firing, you need not be concerned. Slight varia-tions in the bending of the cone are normal and may bedue to the location of the cones on the shelf, the distanceof the cones from ceramic ware, and even variations incones from box to box. This normal variation will have noeffect on your ware.

If your digital kiln shuts off before the large cone on theshelf bends and you’re there when it happens, programthe controller to a higher temperature or add a hold. (Seethe separate digital controller manual for your kiln.)Then turn the kiln back on.

Q When a kiln is taking longer than usual to com-plete a firing, how do you know whether some-thing has gone wrong and the kiln is over-firing?

A You should place pyrometric witness cones onthe shelf so that you can see them through apeephole.

Here’s another way tohelp prevent an over-fire:Learn to estimate kiln tem-perature by the color oflight showing around thelid and peepholes. Thatway, you can tell at a glanceif all is well with your kilnwhen you check it.

Q Is it okay to use oldcones?

A Yes. Age does not af-fect the cones.

Q Do you need to lookat witness cones dur-ing a firing or only afterthe kiln has cooled?

A Position the cones so that you can see themthrough a peephole. Form the habit of looking atthe cones near the expected shutoff time espe-cially if the firing is taking longer than expected.


The Bendingof the Cone

You can watch the cones as they bend. If youwant to slow down the bending for greater con-trol, add a digital temperature hold near the endof the firing. (See the separate controller man-ual.)

The large standard and self-supporting wit-ness cones have reached maturity when the tipbends to the 6 o’clock position.

Large standard cone: The tip should bendstraight down until it just begins to touch thecone holder.

Self-supporting cone: The self-supportingcone should bend downward until the tip is evenwith the top of the base. The tip should be about½" above the shelf surface. If the self-supportingcone tip touches the shelf, the cone is over-firedby a few degrees of temperature.

Self-supporting cones: Left, over-fired or “puddled”; Center,fired to maturity; Right, under-fired.

The light around the edge of the lidand inside the peephole changescolor as the kiln gets hotter. Youcan learn to estimate temperatureby the color of that light.

“My grandmother, who has taught chinapainting for 60 years, coached me during my firstfiring. I treasure the memory of that moment ofmy life with her.”

—Darcy Giesseman

“When I couldn’t get my first little half poundball of clay to center, my teacher kneeled downbeside my wheel, waited for me to stop, and said,‘Hey, it’s just mud. Don’t let it control you. Youcontrol it.’ When I have a problem, especiallywith centering, I just zone out with my hands inposition on the clay, relax my shoulders, and tellmyself, ‘It’s just mud.’ And the clay obeys.”

—Sheron Roberts

“I love the impossibility of ceramics. Justwhen I think I’ve got it figured out, somethingbursts my bubble once again. It keeps me hum-ble. It keeps me interested, challenged, en-thralled.”

—Kelley Webb Randel

FIRINGACCESSORIES

These accessories can be purchased from Paragonthrough an authorized dealer:

ShelvesShelves are flat slabs of fire-

clay that have been fired to ahigher temperature than will beencountered in your kiln. Withmultiple shelves, you can stackmore ware in your kiln than youcould ever place on the bottomof the kiln alone.

Half shelves increase kilnspace by making it possible to fire tall pieces on one sideof the kiln and one or more layers of small items on theother side.

Shelves are strong and will not sag if properly sup-ported and not overfired. But like any other pottery, theywill break if dropped.

PostsPosts are made from the same mate-

rial as shelves. Posts support and sepa-rate the layers of shelves in a kiln. Theshorter the post, the greater the stabil-ity. Posts can be stacked upon one an-other to achieve a greater height, but asingle post is more stable.

½" and 1" posts are used to obtain heights not in yourpost assortment. Avoid using posts taller than 10" by plac-ing tall ware on the top shelf of your kiln.

Recommended Furniture KitsFurniture kits are carefully selected assortments of

shelves and posts that allow you to make the most of yourkiln’s firing capacity.

Shelves should be 1” - 2” smaller than the firing cham-ber of the kiln. If shelves are larger, breakage of the fire-brick walls may occur, because you will not have enoughspace for your fingers as you place the shelves in and outof the kiln.

StiltsAt high temperatures,

glaze becomes molten andsticks permanently to any-thing it touches, such asthe kiln shelf. Stilts preventthis. A stilt is high tempera-ture wire embedded in aceramic base. The stilt sus-pends glazed ware on the wire points to separate the piecefrom the kiln shelf. Stilts also allow air to circulate around

large, flat pieces. Stilts are needed for glazed ware, notgreenware.

Stilts can be used in firings up to 2000°F (1093°C).They cannot be used to fire porcelain and stoneware,which fire to cone 6 - 10. At those temperatures, the wirepoints would embed into the clay or bend. Stilts, however,can be used to fireoverglaze onto por-celain at chinapainting tempera-tures.

Stilt points aremade of a hightemperature metalalloy. You canstraighten metalpoints by bendinggently with pliers.Remove glazebuildup on thepoints with a stiltstone or emerycloth. The oxida-tion of the wire candiscolor the glazeat the stilt mark.Cleaning the wirepoints with a stiltstone solves that problem.

Stilts come in a wide variety ofshapes and sizes. The 3-point tri-angular stilts support bowls, plates,and cups. Bar stilts support longerpieces. Load ornaments and eggson stilt posts.

Remove the stilts from the wareafter firing by breaking the thinfilm of glaze holding them. Thestilt points leave a sharp edge in theglaze. Handle the ware carefully toavoid injury. Re-move the sharp stiltmarks with a stiltstone.


Clean the points with a stilt stone.

Straighten stilt pins with pliers.

Tile and Plate SettersThese are holders used to

stack plates and tiles insidethe kiln. Firing plates andtiles is more efficient with atile or plate setter than placingthese items flat on the shelf.The setters not only savespace in the kiln but also allowair circulation around theware, preventing warping andbreakage. The ware heatsmore uniformly in a setterthan when placed directlyonto a kiln shelf.

Bead RodsCeramic greenware

beads can be piledonto the kiln shelf. Butonce the beads havebeen bisque-fired andthen glazed, they mustbe suspended by stiltrods (also called beadrods). Since the beadsare glazed all over, theycannot be placed on the kiln shelf. Stilt rods are madefrom the same type of wire as kiln heating elementsthough the rods are thicker than elements.

The beads must not be glazed inside the hole andaround the edge of the hole. Otherwise they will stick tothe rod. Space the beads so they do not touch. Suspendthe stilt rods between two posts.

All Purpose, HighFire Kiln Wash

High fire kiln wash is amixture of finely groundminerals that do not fuse atporcelain and stonewaretemperatures. It acts as abarrier between the shelfand dripping glaze. Thekiln shelf must be coatedwith kiln wash to keep ce-ramic glaze and glass fromsticking to it. Without a barrier, the glaze would embedpermanently into the shelf.

Caution: Contact with kiln wash will destroyheating elements.

Brush kiln wash on the tops of kiln shelves and on thekiln bottom to prevent glaze drippings from sticking per-manently to these surfaces. As a powder, high fire kilnwash has an unlimited shelf life. (See page 19.)

PREPARING TOFIRE THE KILNVacuuming the Kiln

Note: Do not breathe brick dust. Vacuum the kilnwith a HEPA filtered vacuum cleaner or a centralvacuum that takes the dust outside.

One of the easiest kiln maintenance tasks you can per-form is regular vacuuming. This is especially important ifyou fire glazes. Vacuum the kiln before every glaze firing.This helps to pre-vent dust particlesfrom landing onglazed ware duringfiring. Vacuum ev-ery four bisquefirings.

Use the softbrush nozzle on avacuum cleaner. Besure to vacuum theelement grooves,the inner surface ofthe kiln lid or roof,and the underside of kiln shelves.

Vacuuming the element grooves may extend elementlife by removing brick dust that settles in the bottom ofthe grooves. Vacuuming the grooves is essential if any-thing has exploded inside the kiln. Pieces of greenwarethat lodge inside the grooves can burn out an element.

Note: Over time, brick dust may accumulate inthe bottom of the element grooves. This can in-terfere with heat transfer from the elements andactually slow down the firings.

Vacuum the kiln often if you use silica sand on theshelves. The sand, which is used to support ware duringfiring, can ruin the elements if it filters down into an ele-ment groove.

As you vacuum the kiln, examine the walls for glass orglaze particles that have embedded into the firebricks.Dig these out carefully with a screwdriver. Otherwise theparticles will embed deeper into the firebrick during thenext firing.

Digital kilns: A static electric charge may build up onthe vacuum hose especially in dry weather. Static electric-ity can damage electronics. Disconnect the power to thekiln before vacuuming. Keep the vacuum away from thedigital controller, the switch box, and the thermocoupletip that extends into the firing chamber.


Separate the glazed beads so they do notstick together on the bead rod.

Tile setters conserve space in-side the kiln when firing tiles.

Kiln wash protects shelves and thekiln’s brick bottom from drops of hotglaze.

If you vacuum with a plastic nozzle, do not letthe nozzle touch the fragile firebricks.

Drying GreenwareOrdinarily, do not use the kiln to dry greenware. The

most expensive way to dry greenware is to heat it in a kiln.The moisture in the clay rusts the kiln, wears out ele-ments faster, wastes electricity, and if fired too rapidly cancause the ware to explode. Moisture trapped in the clayexpands tremendously at the boiling temperature ofwater.

Note: If the ware explodes inside the kiln, let thekiln cool to room temperature. Then vacuum theinterior.

Wet clay contains about 30% water by weight. Duringfiring, moisture from the greenware turns to steam. Asthe temperature rises and the heated air in the kiln ex-pands, moisture escapes by pushing its way into the poresof the firebricks. When the moisture reaches the coolerstainless kiln case and galvanized steel base plate, it con-denses, causing water to drip around the kiln.

The firebricks in a typical 8-sided kiln can absorb ap-proximately 50 pounds of moisture from wet greenware.This reduces the insulating capacity of the firebrick. Italso takes a tremendous amount of electric power to con-vert water to steam during firing. This slows the kiln to acrawl.

If your kiln has been dripping water, fire the kiln emptyovernight on low heat to burn off the moisture in the fire-bricks.

An efficient way to dry greenware is to place it inside anenclosure such as a metal cabinet that contains a smallelectric heater. This is called a hot box. The moisture inthe clay raises the humidity inside the cabinet. The hu-midity keeps the clay surface moist, which prevents thesurface from closing up and trapping moisture inside theware. Thus, the humidity allows the clay to dry evenly. Asthe clay continues to dry and moisture slowly leaves thecabinet, the humidity drops, which causes the clay tofinish drying.

The following suggestions will help you determinewhen the greenware is dry and what to do if it won’t drycompletely:

1 Give the greenware enough time to dry. Dryingtime depends on the thickness of the clay, themethod of drying, and the humidity in your area.

2 Touch the greenware to the inside of your wristor to your cheek. If itfeels warm, it is usu-ally dry. Be sure tocheck the bottom ofa piece, which re-tains moisture lon-ger than the upper,thinner sections.Dry longer if the clayfeels cool or if it hasdark patches, which

indicate moisture. Note, however, that in humidareas, even damp greenware can feel warm.Greenware feels cool due to evaporation. Dampgreenware can feel warm when the moisture in itstops evaporating.

3 If the greenware is still some-what moist after an extendeddrying period or you are undera tight deadline, load thegreenware into the kiln. Propthe lid with the Prop-R-Vent inthe extended position andleave out the peephole plugs.Fire to 200°F (93°C) slowly.Maintain 200°F (93°C) untilthe greenware is completelydry.

Note: If you have a downdraftkiln vent, you can leave the vent on during preheatwith the lid closed and peephole plugs inserted.The vent will help to remove moisture.

Electronic kilns: Use the Preheat feature inCone-Fire mode, or program a 200°F (93°C) preheat seg-ment in Ramp-Hold mode.

Manual fire kilns: Turn the bottom switch on low;leave the other switches off. (The switch setting variesdepending on the size of the kiln.)

“Candling” means firing the kiln at 200°F (93°C) orlower until moisture in the ware has evaporated. If youleave the lid well vented or leave a downdraft vent turnedon during candling, you can get away with using the kiln todry the ware. But you will probably increase the corrosionof steel parts in the kiln especially if moisture is still in theware as the temperature goes up past the candlingtemperature.

Note: Bisque ware has already been through thebisque firing, so it does not have the drying prob-lems of greenware. Nevertheless, after applyingglaze to bisque, allow the glaze to dry before fir-ing. This usually takes a few hours.

Checking for Dryness with a MirrorHold a mirror above the lid or top peephole where hot

air from the kiln will move across the mirror’s surface. Ifthe mirror fogs, thegreenware is still releas-ing moisture. Keep thelid propped and main-tain 200°F (93°C) in thekiln until the mirror nolonger fogs. (If you arefiring with a downdraftkiln vent, you will need toremove a peephole plugor prop the lid to performthe mirror test.)


Greenware that feels cool against thewrist still contains moisture.

The Prop-R-Vent isshown here in the ex-tended position.

Moisture condenses on a mirror heldnear the peephole or the vented lid.

Note: The first time you fire the kiln, water in thefirebricks may fog the mirror for an extendedperiod.

For this test to work, the mirror must be at room tem-perature. The mirror fogs when moisture in the hot aircondenses on the cooler mirror. If you hold the mirror toolong near the kiln, the mirror will heat up and will no lon-ger fog when moisture hits it. So hold it at the lid for only amoment at a time.

Note: You can dry the greenware by placing itaround the kiln during a firing. This uses heatfrom the kiln that otherwise would be wasted.You can place the greenware on metal shelves orrollaway metal tables. Be careful if you place waredirectly onto the lid of a kiln. Too much weightcan crack the lid.

Shelf PreparationHigh Fire Kiln Wash

Kiln wash prevents glaze and glass from sticking per-manently to the kiln shelf and firebrick kiln bottom.Brush kiln wash on the tops of kiln shelves and on thekiln’s firebrick bottom.

Caution: Do not apply kiln wash to the kiln wallsor lid, the underside of shelves, or the posts. Con-tact with kiln wash will destroy heating elements.Wear a respirator to avoid breathing kiln washdust.

Never use a low-fire ceramic type kiln wash, becauseafter firing the kiln above cone 04, the ceramic kiln washwill harden and be difficult, if not impossible, to removelater when you want to fire to hotter temperatures. Allpurpose, high fire kiln wash MUST be used in all kilnsrated to 2300°F (1260°C), even though the kiln is usuallyfired at lower temperatures.

Note: When unloading the kiln, move away fromthe kiln before wiping off kiln wash from the bot-tom of the pieces. If you wipe off the kiln washwhile holding the pieces above the kiln, the dustcan settle into an element groove and destroy anelement.

How to Use Kiln Wash1 Pour a little water

into a disposablecontainer andadd powderedkiln wash until ithas the consis-tency of coffeecream. Stir untillumps dissolve.

2 Use a haik brush(available from

Paragon) or a soft paint brush to apply the kilnwash to the shelf. (The haik brush lays down aneven coating.) Each time you dip your brush intothe kiln wash mixture, swirl the brush around thebottom of the container. This is because the kilnwash settles quickly.

Note: Start the brush stroke an inch or so fromthe edge of the shelf and work toward the oppo-site side. This is to avoid a buildup of kiln wash onthe edges.

3 Apply two or three thin coats of kiln wash changingthe direction of the brush stroke 90° with eachcoat. Let the kiln wash dry for a few minutes be-tween coats. Do not apply thick coats; they tend toflake off.

4 Remove any buildup of kiln wash from the edges ofthe shelf by tracing around it with a finger. Excesskiln wash may break off the edges and fall ontoware positioned below the shelf. Dry the shelvescompletely before firing.

5 Brush kiln washonto the kilnbottom. Protectthe kiln wallsand elementsfrom kiln washwith a piece ofc a r d b o a r d .Never apply kilnwash to kilnwalls or to theunderside ofshelves.

6 Let the kiln wash dry overnight. You can speeddrying by placing shelves in the kiln and heating toaround 200°F (93°C) for an hour. Thekiln-washed shelves are still wet if they feel cool tothe touch.

Note: Do not ap-ply kiln wash topyrometric cones.Kiln washchanges the ma-turing tempera-ture of the cone.

Note: If glaze orglass sticks to theshelf, scrape it offwith a putty knifeat a sharp angle. Wear safety glasses—sometimeschipped glaze becomes airborne. Then recoatthe bare spot with more kiln wash.


Applying kiln wash with a haik brush.

Protect the elements when you apply kilnwash to the brick bottom.

Use a putty knife to remove flaking orcracked kiln wash.

Q I have applied kiln wash to my shelves. Should Ialso kiln wash the underside of the lid?

A Kiln wash should never be applied to the lid orwalls of the kiln, because it could flake off and fallinto an element groove or onto glazed ware. It isespecially important to keep the kiln wash awayfrom elements.

Q The kiln wash is flaking off some of my shelves.

A If the kilnwash is flakingfrom theshelves, youmay be apply-ing it too thick.Remove thekiln wash andapply a newcoat.

Recoating aShelf with Kiln Wash

When recoating a shelf, remove most of the old coatingwith grit cloth (available from Paragon). This is an abra-sive-coated mesh that allows residue to pass through.You could also use coarse sand paper. Removing the oldcoating gives you a smooth surface to start with. Wear arespirator when removing kiln wash. Then recoat theshelf using the directions on page 19.

Kiln wash will usually last for many firings. When thekiln wash begins to crack or chip, apply a fresh coat.Scrape glaze drops off the shelves or dig them out of thebrick bottom as soon as they appear. Then apply a newcoat of kiln wash to the bare area.

100 Mesh Alumina Hydrate SandShelves can become warped at stoneware and porce-

lain temperatures. Large, flat stoneware pieces placed di-rectly onto a warped shelf become warped at high tem-peratures. But there is a way around this: Place the wareover a layer of alumina hydrate that has been sprinkledonto the shelf. The sand evens out the warped surface sothe bottom of the ware remains flat during firing. In addi-tion, alumina hydrate acts as miniature ball bearings to al-low the clay to move as it shrinks during firing and helpsto separate the ware from the shelf for more even heatingof the piece. You can use the alumina hydrate over andover. It is available from pottery supply distributors.

Note: We do not recommend the silica sand avail-able from home improvement centers as a sub-stitute for alumina hydrate unless you first test it.If the sand contains iron particles, it will stick tothe ware.

Caution: Do not breathe alumina hydrate dust.Wear a respirator.

How to Use Alumina Hydrate

Note: If you use a fan to lower the firing roomtemperature, do not aim the fan directly at thekiln. The breeze can stir the sand (alumina hy-drate) inside the kiln. This could ruin glazedpieces and scatter sand into the element grooves.It is okay to use a down draft kiln vent such as theOrton Vent Master. When correctly installed, thevent does not create enough airflow to stir updust inside the kiln.

1 Do not place sand on the kiln’s brick bottom. Useit only on the shelves. The sand can work its waybetween the firebricks. Pour the sand onto theshelf before lowering the shelf into the kiln. If youpour the sand on the shelf inside the kiln, dustparticles are more apt to float inside the firingchamber, scattering onto your pieces.

2 Do not pour the sand onto the shelf from a largebag. Use a scoop instead. A scoop stirs up lessdust. After you have poured the sand onto theshelf, a small ruler is helpful in spreading thesand.

3 Use the sand sparingly on the shelf for most pro-jects. Use a thicker layer under the ware if you areconcerned about glazes running.

4 Keep the sand 2" - 3" away from the edges of theshelf. If the sand falls off the edges, it may filterdown into the element grooves or onto glazedware on the shelf below. This is especially impor-tant with half shelves.

5 As you lower the shelf into the kiln, hold the shelflevel. If it tilts, the sand could fall off the edges.

6 When unloading the kiln, remove the shelf andthe ware together. If the ware is too heavy to liftout with the shelf, then hold each piece of wareaway from the kiln before rubbing the sand off


You can also remove loose kiln wash with gritcloth and then apply a new coat.

the bottom of the piece. If you hold the ware overthe shelf as the sand falls from the piece, the parti-cles could fall into an element groove.

7 Pour the alumina hydrate from the shelf into astorage container. Use a wide-mouth containerthat will catch the sand as you tilt the shelf. A plas-tic container with lid works well. Save the sand forfuture firings.

8 Vacuum the kiln after every firing with a soft brushattachment. Be sure to vacuum the elementgrooves.

Removing Glaze from the Shelves1 Place the shelf on a soft surface such as a thin sheet

of Styrofoam.

2 Wearing a dust mask and safety glasses, gently tapthe glaze drippings at a sharp angle with a puttyknife.

LOADINGTHE KILNHow to Store Kiln Furniture

Store kiln furniture in a dry area. Moist shelves cancrack or even explode inside the kiln. A freshlykiln-washed shelf should be allowed to dry thoroughly,then fired slowly to allow any moisture in the shelf toevaporate.

There is less danger of cracking if you store shelvesvertically in a shelf rack or even leaning against a wallrather than flat. If a piece of clay or other material lodgesbetween horizontally stacked shelves, weight pressingdown can crack a shelf. (However, as long as the stack isno higher than three or four shelves and the shelves areclean, you can store them flat, too.)

Store shelves so that the sides with kiln wash face eachother. This prevents flakes of kiln wash from transferringto the underside of other shelves.

Store posts of the same length together.If a shelf cracks, break it apart at the cracks and use the

pieces as smaller shelves.

Note: You may find it helpful to draw a shelf pat-tern on a table and plan the load for each shelf be-fore you begin loading the kiln.

Guidelines forLoading the Kiln

Loading a kiln is like putting together a jigsaw puzzle.You may find it the most interesting aspect of firing, be-cause it requires thought and planning.

How To Handle Kiln ShelvesOne of the secrets to keeping your kiln in good condi-

tion is in the way you hold the shelves when you load orunload the kiln:

1 Check each shelffor cracks.

2 Work slowly andcarefully. Treat thekiln as if it were apiece of fine furni-ture that you didn’twant to scratch.Don’t touch thefirebrick walls ifyou can help it.Touching the walls will cause dust to fall ontoglazed ware.

3 Tilt the shelf as you lower it into the kiln. Center itso it doesn’t touch the kiln walls. At all times, beaware of the location of the thermocouple or Kiln


Hold the putty knife at a sharp angle to remove glaze from a shelf.

Do not let the shelf touch the walls.

“When you concentrate on making a pot, youhave no time to dwell on your problems. I know atherapist who used clay in working with suicidalteens. She has worked wonders with these kids.”

—Mike Gordon

“The profound experience of working withclay is to have a three dimensional image in yourhead, and then have it come out through yourhands.”

—Marie Gibbons

“Many of our customers, in very stressful jobs,find release through clay. One, a doctor, foundclay to be the road back from a mental break-down.”

—Stephen Mills

Sitter tube so that you avoid bumping the shelfagainst it.

4 As you level the shelf into position, center it in thefiring chamber. Top-loading kilns: Positionyour hands so that they are at the firebrick cor-ners. This offers more space than straight sec-tions of the walls.

5 If full shelves are too heavy for you to load, use halfshelves. Not only are they lighter, but they arealso less apt to touch the walls during loading andunloading.

6 Do not jar the kiln after loading, or the ware or ashelf could fall over and break. Shelves should be1” - 2” smaller than the firing chamber.

7 Do not allow anyone to load or unload your kilnuntil you have trained them.

The Basics of LoadingDisconnect the power before loading the kiln.Hang a portable light from the kiln’s lid handle if your

room is poorly lit.Before loading the kiln, be sure all the ware is rated to

the same pyrometric cone. Low-fire ware fired with a loadof stoneware could melt into a puddle, ruining kilnshelves.

Avoid back strain. When possi-ble, load empty tile setters into thekiln. Then add the tiles to the set-ters that are already in position.This is easier than lifting fullyloaded tile setters into the kiln.

Ordinarily, load pieces of me-dium height on the bottom shelfand tall pieces on the top shelf.This improves the stability ofposts since short posts in the bottom of the kiln are morestable than tall ones. But if you have difficulty reachingdown into a deep kiln, leave the bottom shelf in place andload tall pieces onto it. A short stepladder or concreteblock is an aid to reaching into a deep kiln.

We urge the use of at least one large pyrometric conebehind the peephole on a kiln shelf in every firing. Placecones 8” - 12” from the peephole. (The minimum dis-tance between the cone and a peephole is 3”. This is toprevent exposure to cool air.) Check the cone through thepeephole before placing a shelf over it.

Large, heavygreenware pieceswill fire best if placedacross two halfshelves positioned atan even height.

After loading thekiln, close the lidgently. Jarring the lidwill not only damage

it but will also cause dust to fall onto glazed ware on thetop shelf.

Loading for EfficiencyTo make full use of

your kiln’s firing capac-ity, group similar sizesof ware together insidethe kiln. (Begin group-ing similar sized wareas you lay the pieces outto dry prior to firing.)Fill empty areas of theshelf with small piecessuch as medallions.They make good glazetesting samples thatyou can sell or give awaylater.

Stack ware on half shelves to take advantage of blankspace next to tall pieces.

When firing pieces of varying heights on the sameshelf, the tall pieces should go in the center. This is toavoid blocking radiant heat from reaching the shorterpieces.

To save space during thelow-fire ceramic or stone-ware bisque firing, you canplace bisque ware withinother larger pieces. Theware shrinks during firing,so pieces that are stacked to-gether must have shrinkage room. Otherwise they willcrack.

Place small, light greenware pieces directly on thefloor of the kiln. Leave ample room for air to circulatearound their bases since this area is difficult to heat.

A good place for tall pieces is the top shelf, with noposts or shelves above them.

DistancesInsidethe Kiln

Keep ware at least 1"away from a heatingelement. Glazes maybubble and land on an el-ement if the ware is tooclose. If you fire a piecethat is so large that a tip ofit comes closer than 1” toa kiln wall, place that sec-tion of the piece betweenelement grooves and notdirectly opposite an ele-ment.


Large greenware pieces can be firedacross two half shelves.

Use half shelves to load layers of warenext to tall pieces.

Keep ware at least 1” away from theelements. If ware extends closer than1” to a wall, place it between rows ofelements.

The minimumspacing betweenshelves is 2 ½". Youcan achieve this mini-mum 2 ½" height bystacking a ½" post ontop of a 2" post. Shelvesmust be stacked sothere is at least one rowof heating elements be-tween any two shelves.

The posts usedwith each layer ofware should be atleast 1" taller than theware. Keep a rulernear your kiln. As youfill a shelf with ware, laythe ruler across twoposts or the top of thekiln to make sure theware is not too tall.

Keep all ware andkiln shelves at least1" away from theside, top, and bottomof the end of the KilnSitter tube or digitalthermocouple. If thekiln is nudged duringfiring and the shelvesmomentarily shift posi-tion, the Kiln Sitter orthermocouple couldmalfunction.

Make sure at leastone element grooveis between the topshelf and the top ofyour kiln. The top ofware should be at least1" lower than the lid. Ifthe ware on your topshelf is over- or un-der-firing, try using twohalf shelves instead of afull shelf. Stagger theheight of the shelves.

Glazed WareAs you load each shelf into the kiln for a glaze firing,

wipe off or vacuum dust from the underside of the shelf.Lower the lid gently. Rough handling will crack the lid.

This may result in dust falling from the cracks ontoglazed ware on the top shelf. If your lid is cracked, load

smaller items on the top shelf leaving a blank space on theshelf under the lid crack.

Separate glazed ware by ½". If pieces are placed tooclose together, a glaze of one color may contaminate theglaze of a different color on the next piece.

Do not wipe dried glaze drips from the ware while youare standing over the kiln. The glaze particles may fallinto the kiln and land in an element groove or fall into thelouver of a switch box. This could cause an element toburn out or a wire connection to fail.

Some glazes tend to run off the ware and onto theshelf. In the worst cases, the running glaze eats throughthe kiln wash and embeds into the shelf. You can preventthis by placing broken pieces of kiln shelf under the ware.The shelf piece will catch the glaze. Or roll out a ¼" thicklayer of clay, cut it into circles with a can (similar to using acookie cutter), and coat the clay with kiln wash. Place theround “coaster” under the ware to protect the shelf.

For kilns with a downdraft vent such as the Orton Mas-ter Vent, do not load glazed ware directly under the air in-take holes in the lid.

Ware that is prone to warping, such as ware with thinwalls or flared tops or large bowls, should be placed awayfrom the elements. The bottom of ware that extends outpast the edge of a shelf may warp.

Pieces that go together, such as matching cups andsaucers, should be placed next to each other on the kilnshelf. This helps assure uniformity in glaze color. Tokeep holes in glazed salt and pepper shakers from closingin with glaze, insert tooth pick pieces in the holes. Theywill burn away during the firing.

Heat DistributionInside the Kiln

You may remember from early science class that heatrises. This is called convection. Kilns tend to fire cooleron the bottom, but not because heat rises. Movement ofheat through convection ends at around 1100°F (593°C).At 1700°F (926°C), air has only about one-tenth the num-ber of molecules as at room temperature. This is whythere is little airflow in an electric kiln at hightemperatures.

The bottom and top tend to stay cooler because thebrick bottom and lid are large thermal masses that absorbenergy. Paragon compensates for this by making the bot-tom and top elements fire hotter than the centerelements.

You can improve heat distribution by loading less warein a cool section of the kiln and more ware in a hot section.Slowing the firing also helps.

The best way to determine how to load your kiln foreven heating is to place witness cones on every shelf. Youwill quickly know which section fires hotter and thereforeshould be loaded heavier. The heavier a section of firingchamber is loaded with ware, the cooler it will fire.


Have at least one element groove be-tween the top shelf and the top of thekiln.

Keep ware and shelves at least 1” awayfrom the thermocouple.

Lay a ruler across the top of the kiln tomake sure the ware is not too high.

Minimum spacing between shelves is 2½”. You can stack posts to achieve thatheight.

Q How do you load the kiln if you are firing it halfempty such as when you are firing several piecesfor a show that has a tight deadline?

A Do not leave the top half of the kiln empty. Dis-tribute the ware evenly throughout a lightlyloaded kiln. But if you are firing a tall piece or forsome other reason you cannot distribute the loadevenly, then fire the kiln slowly.

Q Is it okay to place ware directly onto the brickbottom?

A Yes. Since the massive firebrick bottom ab-sorbs so much heat, you should place only lightpieces on the bottom, or pieces that can be firedto a slightly lower temperature. Do not placeglazed ware on the brick bottom; running glazewill damage the firebricks. Instead, place 1" postson the firebrick bottom and a shelf on top of theposts. The bottom shelf will protect the firebrickbottom from glaze.

Note: You can also supportthe bottom shelf with smallbroken pieces of shelves.They will help to distributethe weight of the kiln loadover a larger area of the kilnbottom than would 3 or 4separate posts.

How to Position PostsStack posts so they

are directly in line witheach other vertically. Ifposts are stacked ver-tically offset from eachother, shelves will beless stable and moreprone to warp atstoneware and porce-lain temperatures. Acantilevered shelf can break from stress. The weight onvertically aligned posts will also help to hold up a shelf thatcracks.

Use 3 posts for a kiln load of fullshelves. Three posts are more stablethan 4 posts, because with 3 pointsof support, the shelves will not rock.Use 6 posts for a set of half shelves.

When possible, position posts to-ward the kiln walls and away fromthe center of the kiln. This placesmost of the weight of the kiln loadclose to the kiln stand and away fromthe kiln center, which has less sup-port.

Bead RodsFire small low-fire or

stoneware glazed beads onbead rods that are sus-pended between two posts.Keep the beads separatedon the rod. If they touch, the glaze will make them sticktogether. Keep the glaze away from the bead holes.

You can also center a bead rod (also called a stilt rod)over a horizontal post so that the rod extends past the poston each side. Then load an equal number of beads oneach end of the rod. This is an efficient way to fire manybeads since one short post can hold several rods. Be care-ful not to jar the kiln, or the rods could fall.

Firing Large WareAcross Half Shelves

Large ware such as platterssometimes extend over two halfshelves. If the shelves are un-even, the platter may warp dur-ing firing. To solve this prob-lem, pour a small amount ofalumina hydrate onto eachshelf. The powder will form aneven surface for the ware. Youcould also place small clay balls or pencil-sized strands ofclay under the ware. Another alternative is to place theware on a small shelf that spans the two half shelves.

Tile Holders

Tile holders are a special type of kiln furniture. Theymake efficient use of kiln space and allow air to circulatearound tiles for even heating, thereby reducing tilewarpage and cracking. Tile holders can be stacked insidethe kiln.

Some tile holders can hold tiles horizontally or verti-cally. Position the tiles horizontally when using glazesthat tend to run down a vertical plate or tile during firing.On the other hand, positioning the tiles vertically in theholders lessens the chance of dust falling onto the glaze.


You can support the bottomshelf with small shelf pieces.

Posts should be vertically aligned asshown in the left diagram.

Use 3 posts per shelf.

You can fire large piecesacross half shelves.

FIRING THE KILNCheck the kiln from time to time during operation.

Observe the sounds that it makes, and write down thelength of firing time. Once you are familiar with the nor-mal operation of your kiln, you will often know just by ob-servation if something goes wrong. This can alert you tointerrupt the firing before the ware is damaged.

The Stages of FiringCeramists like to fire their kilns fast to save time and

energy. Fast firing, however, can cause many mistakes.Fire greenware slowly especially during the early

stages. A fast greenware firing does not save time if itcauses glaze crazing, pinholes, or cratering. You can usu-ally fire glazed ware faster than greenware, but slow thefiring near the end so that glaze defects have time to heal.

The thicker the ware and the more densely packed thekiln, the slower the kiln must fire to insure that the heatreaches all of the ware. Pieces that have thin and thick ar-eas must also be fired slowly to allow the thick areas tocatch up in temperature with the thin areas.

Stage One: Water Smoking—Up to 800 -900°F (426 - 482°C)

All clays contain water. The first stage of firing burnsoff the water in ceramic greenware. As the water heats, itexpands and is pushed out of the clay. This is called watersmoking.

Fast firing during this stage can lead to disaster. If thekiln heats past the boiling point of water—212°F(100°C)—the water in the clay will expand too quickly.When the ware breaks during firing, it is usually at thisfirst critical stage. Water boiling inside the clay can ex-plode, damaging not only the ware but also the walls of thekiln. When the ware sounds like popcorn inside the kiln,you know you have fired too fast.

Maintain temperature at 200°F (93°C) or lower duringwater smoking, and vent the kiln so that the water can es-cape. If you don’t have a pyrometer or digital controller,leave the bottom switch on low and the other switchesturned off.

Stage Two: Dehydration and QuartzInversion—900° - 1100°F (482°C - 593°C)

After the initial water smoking stage, the clay contin-ues to lose water at a molecular level until about 1100°F(593°C). At that point, the clay changes chemically intofired ware. At around 1060°F (571°C), the clay goesthrough quart inversion, which is the point at which thesilica in the clay expands. Through 900° - 1100°F (482°C -593°C), the molecular water must exit the clay slowly, es-pecially if the clay pieces are large.

Stage Three: Oxidation—500° - 2000°F(260°C - 1093°C)

Impurities burn out of the clay from the very beginningof the firing, but especially during the Oxidation stage.The kiln atmosphere must have oxygen to burn the im-purities. The ware must be heated slowly to give impuri-ties, such as carbon, enough time to become gases andcombine with oxygen. The thicker the ware and theheavier the load, the slower the ware must be fired.

As the clay reaches higher temperatures, the compo-nents of the clay fuse together, sealing the clay surface. Atthis point, remaining carbon and other impurities be-come trapped inside the ware. The trapped gases expandbeneath the surface, bloating and cracking the ware.

Glaze pinholes, bubbles, crazing, and peeling are oftencaused by gases that had not burned out fully in thegreenware firing. These gases are pushed to the surfaceduring the glaze firing. Lead-free glazes are especiallysensitive to trapped gases. These glazes lack the flux thatsmooths out glaze defects. Trapped impurities turnwhite bodies gray and weaken the finished ware. Theycause mildew in porcelain.

Stage Four: Maturity—1300° - 2300°F(704°C - 1260°C)

This is the stage where the heat has transformed theware to the degree intended by the clay manufacturer.

Over-glazes

1000° - 1500°F (537° - 815°C)

Low-fire ceramics

1700° - 2100°F (926° - 1148°C)

Porcelain and stoneware

2100° - 2400°F (1148° - 1315°C)

See your clay supplier for the recommended firingtemperature of your clay. It is listed as a pyrometric conenumber.

When to SpeedUp the Firing

After the quartz inversion—1000° - 1100°F (537° -593°C)—clays in the bisque, or greenware firing, can befired faster. By this stage, the water has been completelydriven out of the clay. Actual speed will depend on howmany impurities the clay contains. Slow the firing againduring the last 200°F (111°C) of the firing.

How fast you should fire depends on the thickness ofware and type of clay. Thin-walled, low-fire ceramics canbe fired much faster than stoneware. Fire test pieces in asmall kiln. Experiment with firing speed before risking anentire load of ware. Always test-fire clays you are unfamil-iar with. If test results are satisfactory, but you want to firefaster, try further tests at increasingly faster rates.

Firing the ware too fast and with insufficient ventingcauses more problems than any other firing practice. Solong as the clay and glaze are designed properly, you will


get almost foolproof results by firing slowly, venting thor-oughly, and using witness cones. These are the basics offiring.

Note: Firing speed, especially during cooling, canhave a dramatic effect on the glaze.

VentingAt the beginning of a ceramic firing, the fumes and

moisture inside the kiln must be removed by venting.Moisture not vented out of the kiln early will rust the kiln.As the heated air in the kiln expands, it escapes by push-ing its way into the pores of the firebricks and out to thestainless steel case and switch box.

Note: If you are using a fan to lower room temper-ature, do not let the fan blow air into the openpeepholes.

Manual Venting (Withouta Motorized Vent)

The simplest form of venting is to remove the peep-hole plug(s) and prop the lid with the Prop-R-Vent (seepage 10). After the vented period is over, lower the lid allthe way, and close the bottom peephole (if you kiln hasmore than one peephole). You can leave the top peepholeplug out throughout the firing. But if you are getting aglaze defect near the peephole, then insert the top peep-hole plug after the venting period is over. Sometimes ex-posure to air crazes the glazed ware that is placed near anopen peephole.

Note: After the venting period, you may want toleave out the top peephole plug. This allows extraventing throughout the firing.

The Downdraft Vent

The downdraft vent system pulls a small amount of airfrom the kiln, dilutes it with room air, and vents the air tothe outside. The vent air collection cup is positioned un-der a top-loading kiln and usually on the back wall of afront-loading kiln. The vent removes fumes throughsmall holes drilled into the firebricks. There are severalbrands of vents available; one is the Orton Vent Master.

The patented Orton Vent Master not only vents fumesfrom the kiln but also improves firing results. It pullsfresh oxygen into the kiln for brighter colors, especiallynoticeable with red and orange glazes and decals. TheVent Master draws air from the kiln, dilutes it with roomair, and pushes it outdoors through a vent hose.

The extra oxygen and increased air movement helpburn carbon out of the clay, which eliminates a host of fir-ing problems: bloating, dark patches in the clay, porcelainmildew, pinholes, pitting, blisters, and bubbles. The VentMaster prevents fumes from entering the firing room.You can fire even lusters, decals, metallics, andpate-de-verre glass without strong odor.

The flow of fresh air helps even out the temperaturethroughout the kiln.

Note: On switch-operated kilns, the vent also ex-tends the life of the Kiln Sitter tube assemblysince fumes by-pass the tube.

With manual venting, the peephole plugs are removedand the lid is propped. With a downdraft vent, however,keep the lid closed and peephole plugs inserted through-out the firing. Otherwise the Orton Master Vent will notremove the fumes. This is because the Master Vent re-quires negative air pressure inside the kiln.

The Vent Master increases firing time by about 5 min-utes for firings up to cone 4; 12 minutes for firings fromcone 4 to 10. It has little effect on the kiln’s ability to reachmaximum temperature.

Keep the kiln room clean. Dust that enters thedowndraft vent fan can cause the vent to wear out prema-turely.

Q Does the downdraft vent circulate enough airinside the kiln to stir up dust or specks of kilnwash?

A No. There is little air flow inside the kiln from aproperly installed downdraft vent.

The Downdraft Vent Air Intake HolesIf you order your top-loading kiln with the down-draft

vent, the lid will have ¼" air intake holes drilled in the lid.Try not to place ware directly under these lid vent intakeholes. The room temperature air coming in through theholes can cause small areas of glaze imperfection such ascrazing, cloudiness, or even cracking of the ware. Thevent intake holes should be drilled toward the outer edgesof the lid so they won’t affect ware placed in the main areaof the top shelf.

One way to protect ware from cool air under an intakehole is to temporarily plug the intake hole with ceramic fi-ber. Then re-route the air into the kiln through a drilledpeephole plug (available from Paragon). The hole in theplug should be no wider than ¼". Keep ware at least 3"from the drilled peephole plug.

Sometimes a loose peephole plug allows the vent topull enough air into the kiln to cause glaze blemishes. Inthis case, keep ware 3" away from the peephole. Or wrap


Installing the Orton Vent Master. The fan and fan housing areseparate from the air intake cup shown above. The intakecup slides into the flange supports in the top of the kiln stand.

the peephole plug with asmall piece of ceramic fiberblanket to make it fit snugly.(Ceramic fiber is availablefrom ceramic distributors.)

The Downdraft Vent Air Exit HolesIn most top-loading kilns, the exit holes are drilled in

the kiln bottom. You can place ware near the vent exitholes. Unlike air from the intake holes, the air at the exitholes is hot, so air movement there will not affect theware. Keep the exit holes free of dirt. If the holes becomeplugged, the vent will no longer remove fumes from thekiln.

If you fire a top-loading kiln with the Orton VentMaster turned off or removed for repair, cover the air exitholes in the kiln bottom. An easy way to do this is to place akiln shelf supported by 1" posts over the holes.

The Downdraft Vent During CandlingCandling is a stage of firing where the temperature is

kept below 212°F (100°C). (See page 18.) You can leavethe downdraft vent on during candling. Moisture will getinto the fan and vent duct but will dry out later as the kilnheats up. Leave the lid closed and peepholes plugged.

When to Turn Off the Downdraft VentAfter the kiln has completed the firing and shut off,

leave the vent on for at least another 30 minutes. This isbecause even though the ware has fired to maturity, it stillreleases fumes.

You can leave the vent on throughout the cooling pe-riod. From the top temperature down to 1000°F (537°C),the vent has no effect on cooling time. From 1000°F(537°C) down to room temperature, the vent will de-crease cooling time by about two hours.

Odors Detected in the Kiln Room WhenRunning the Downdraft Vent

If you can detect odors even with the vent running,check the following:

1 Make sure you can hear the fan spinning.

2 The holes that draw air out of the kiln must be freeof obstructions. If the exit air holes are in the bot-tom of your kiln, the bottom shelf should be posi-tioned at least 1" above the kiln floor. The shelfmust not block the holes.

3 The intake and exit vent holes must be of the cor-rect number, size, and location in your kiln. Seethe vent instruction manual to be sure, or call thevent manufacturer. The vent housing must coverthe air exit holes on the outside of the kiln.

4 Hold a match near an air intake hole to verify thatthe vent has created a negative pressure inside thekiln. The flow of air should cause the smoke andflame to move toward the hole.

5 Insert all the peephole plugs and keep the lid/doorfully closed throughout the firing.

6 Check the vent duct for leaks especially where theduct attaches to the outside flapper in the wall.

7 Make sure the duct is free of obstructions and thatthe vent flapper on the outside of the building canopen freely. Go outside. You should feel warm aircoming out of the vent.

8 Is it a windy day? Wind can blow air into the outsidevent duct opening.

9 Check the condition of the fan. It may be cloggedwith dirt.

10 If you fire ware that contains many impurities, youmay need to fire smaller loads.

CoolingSlow Cooling

The rate of cooling dramatically affects the appearanceof some glazes. People are surprised to find that by slow-ing the cooling of their electric kiln, they can get a glazeeffect that they thought was possible only in a gas kiln.Sometimes a glaze looks better on the inside of a pot thanthe same glaze on the outside simply because the insidecools more slowly.

The temperature range that has the strongest effecton glaze appearance during cooling is 1800°F - 1400°F(1000°C - 760°C). Turn the elements back on to slow thecooling in this range.


Keep the peephole plugs insertedif your kiln has a motorizeddowndraft vent.

If a peephole plug falls out of thekiln, wrap it with a small piece ofceramic fiber paper. That will holdit in place.

The drilled peephole plug avail-able from Paragon has a 1/8” hole.

Fast CoolingThere may be times when you need to cool a load rap-

idly because of a tight deadline. A downdraft vent such asthe Orton Vent Master reduces cooling time by around 2hours.

Another method is to aim a small fan at the kiln. Thiswill reduce cooling time by about 1 ½ hours. Make surethe lid is closed all the way and the peephole plugs are in-serted. Do not aim the fan directly at the peepholes; aim iton the other side of the kiln away from the peepholes.

Cooling too rapidly may cause problems such asbreakage of the ware. If this happens, cool more slowlyfrom 1000°F - 500°F (537°C - 260°C).

When Can You Unload the Kiln?Wait until the kiln cools to room temperature before

unloading. The ware should be cool enough to unloadbare-handed. Otherwise glazes may craze. If this hap-pens, the ware will make afaint pinging sound as theglaze contracts on the ware.

Note: When unloadingthe kiln, wear leathergloves to protect yourhands from small glazeshards.

The Basics of FiringKeep a Firing Logbook

One of the easiest ways to learn about your kiln is tokeep a firing logbook. When firing the kiln for the firsttime in awhile, you can review your logbook to regain aquick “feel” for the kiln. The logbook is vital if you are ex-perimenting with glazes or other materials. Informationto record in your logbook:■ Date

■ Digital: a) Cone-Fire firing speed and Hold or b)Ramp-Hold program

■ Starting time

■ Total firing time

■ How long the lid was vented

■ Type of pieces

■ Firing results (i.e., color of glazes)

In addition, think of the logbook as a diary. Write downanything you learn about your kiln each time you fire it.

Include a simple sketch showing shelf spacing insidethe kiln. Include the height of posts and the type of wareon each shelf. Sketch a diagram of the pyrometric conesshowing how far they bent. Even a rough sketch containsa lot of information.

Low- and High-Fire ClayClay is usually fired twice. The first firing is the

greenware, or bisque, firing; the second is the glaze fir-ing. The greenware firing hardens the raw clay so that itcan accept glaze.

Note: Greenware is unfired clay. Bisque is firedclay that has not yet gone through the glaze firing.

Q What is the difference between firing low- andhigh-fire greenware and glaze?

A Low-fire greenware is fired to a higher temper-ature than the glaze firing. High-fire greenwareis fired to a lower temperature than the glazefiring.

Caution: Do not fire plaster, plaster of paris, orpolymer clay in the kiln. They are not designed tobe fired to high temperatures.

GlazesGlaze and clay must expand and contract at the same

rate. If the glaze shrinks more than the clay, the glaze will“craze,” forming a pattern of small cracks. If it expandsmore than the clay, it will “shiver,” breaking off in sec-tions. Test each clay and glaze combination using clayscraps such as broken bisque pieces.

Note: Instead of making glaze test samples onthrowaway clay scraps, create something usefulfrom the tests. For instance, test glazes on smallclay disks that include a hole for a chain and astamped design on the front. Give them away orsell them as pendants. What you consider glazeimperfections or ugly test colors may be beautifuljewelry to others.

Your hands must be clean when touching glazed ware.Oil and hand lotion will leave fingerprints. If you scrapeoff or damage the color during handling, you can usuallyrepair it by applying more glaze over the damaged spotbefore firing. Allow the glazes to dry before firing.

Scheduling a FiringIn your notes, write down the total firing time for each

type of ware. Then calculate when to begin the next firingso you will be near the kiln at the expected shut-off time.Never leave a kiln unattended, especially near the shut-offtime.

If a firing would ordinarily end after you leave the stu-dio, start it sooner. One way to do this is to pre-heat the


A small 4” diameter fan can reduce cooling time by 1 ½ hours.

ware the night before on low heat—200°F (93°C)—sothat the next day the kiln will fire to completion sooner.

Basic Guide to Firing CeramicsEven if you are a beginner, you should get good results

by following these guidelines:

1 Dry the greenware thoroughly before firing. Placethe ware against the inside of your wrist. The wareshould feel warm. Drying the greenware will helpeliminate explosions caused by moisture in theclay turning to steam.

2 Know the cone number for each clay and glaze, andfire to the correct cone. Correctly label clay storagecontainers.

3 Make sure all the pieces that you fire in a kiln loadare rated to the same cone number. Firing low-firepieces in a high-fire load can melt clay into a pud-dle and ruin shelves.

4 Place pyrometric self-supporting witness cones ona kiln shelf. The cones are inexpensive, take only amoment to use, and verify that the clay and glazesreceive the correct amount of heat work.

5 Keep shelves and ware atleast 1" away from the ther-mocouple or Kiln Sittertube. Ware or shelvesplaced too close to the ther-mocouple can cause inac-curate readings. Itemsplaced too close to the KilnSitter (used on switch-op-erated kilns) can cause anoverfire by preventing therod from dropping.

6 Vent the firing chamberduring the initial stage of firing. Either prop the lidor use a down-draft kiln vent.

7 Fire slowly enough to burn out impurities from theclay. Most firing problems are caused by either apoor fit between clay and glaze or firing too fast.

8 Monitor the kiln during firing. Occasionally checkthe kiln, especially near the end of the firing.

9 Become familiar with the color around the lid andwith the noises that a kiln makes during firing.With practice you can judge the approximate kilntemperature just by the color of light around thelid.

The First Firingin Your New Kiln

The first firing should be to cone 01 - 2046°F(1119°C), which is hot enough to soften the elements andseat them properly in their recessed grooves. It will alsoform a good oxide coating on the elements for longer ele-ment life.

Foreign materials interfere with the formation of thisoxide layer. So for your first firing, position only posts andkiln-washed shelves in the kiln with pyrometric conesplaced in front of a peephole. Air must circulate aroundthe empty shelves, so separate them with posts as if theshelves were loaded with ware. The shelves may crack ifyou stack them in the bottom of your kiln.

Note: Test-fire new kiln furniture any time youbuy it in the future. Load the furniture in the kilnas described above, and fire it without ware. Thisremoves moisture from the new furniture andprevents a hidden crack in a shelf from breakingthe first time and ruining a load of ware.

Make sure the power cord is pressed all the way intothe wall outlet and that the firing room is free of flamma-ble materials. As the kiln fires, place your hand on thekiln’s power cord for a couple of seconds to check thetemperature. It is okay if the cord is slightly warm, but itshould never feel hot.

Do not be concerned withthe light that appears aroundthe edge of the door or lid. It isnormal. As long as the lid ordoor is closed all the way,there is little heat loss. Do notbe concerned with the click-ing sound that the kiln makesduring operation. It is thesound of relays on digitalkilns or infinite controlswitches on manual kilns and is normal.

1 Seat the elements in their grooves by performingthe kitchen knife test (page 7).

2 Empty the kiln and clean with the brush attach-ment on a vacuum cleaner.

3 Apply Paragon all-purpose, high fire kiln wash tothe kiln bottom and the tops of shelves (page 19).

4 Manual-fire kilns: Adjust and test the Kiln Sit-ter. (See the separate “Paragon Switch Operated


Self-supporting cones on the kiln shelf verify that the clay and glazes re-ceive the correct amount of heat work.

Keep shelves and ware atleast 1" away from the ther-mocouple or Kiln Sitter tube.

The line of light that appears un-der the lid is normal for a kiln.

Ceramic Kiln Instruction and Service Manual.”)Insert an 01 small cone on the Kiln Sitter conesupports. (Reminder: Remove and save the firinggauge.)

5 Load the shelves into the kiln, separating themwith posts. Do not load ware into the kiln for thisfirst firing. Place an 01 large cone on a shelfwhere it can be seen through a peephole.

6 Prop the lid with theProp-R-Vent. Close the lid afterone hour. Leave the peepholeplugs out of the peepholes.(Unless you are firing with a mo-torized downdraft vent. See page26.)

Monitor the kiln closely during thisfirst firing. Periodically look at the conethrough the peephole. (Be sure to wearfiring safety glasses.) When the shelfcone bends to 6 o’clock, the kiln shouldshut off. If it doesn’t, turn it off within 10 minutes. Writedown the total firing time. This will help you predict fu-ture firing times. After the kiln shuts off, leave the lidclosed until the kiln has cooled to room temperature.Cooling time is usually twice the firing time.

Always make sure the kiln has shut off before leaving itfor the night. Do this with every firing!

Q I have noticed a soft buzzing noise while mykiln fires. This worries me.

A Magnetism is formed when electricity passesthrough a coil of wire such as a heating element.Depending on where you live, AC electricitychanges direction 50 to 60 times per second.When it flows in one direction, the coils attracteach other. When it changes direction, they repeleach other. That causes the humming noise. Youwill notice that the humming lessens as the kilngets hotter. This is because the element coils be-come soft and no longer vibrate.

Loading and FiringLow-Fire Greenware

Low-fire greenware has a firing range from cone 06 to02. The greenware must be bone dry before firing. Oth-erwise, it will crack or even explode in the kiln. Check fordryness by touching to a cheek or against the inside of awrist. Ware will be cold if it is not dry. Another indicator ofmoisture is patches of darker color in the clay.

Handle greenware carefully. Cradle the pieces fromthe bottom with both hands. Do not lift by a rim. Low-firegreenware pieces do not stick together during firing.Therefore, greenware may be stacked so that it toucheseach other. Fill shelves by placing small items aroundlarger ones. You can also place light greenware pieces in-

side larger ones. This is called nesting. Be sure there isplenty of room for expansion inside the larger pieces.Pack nested pieces lightly so that heat can still circulatefreely around each piece. Black rings in the fired ware in-dicate that the nested pieces were packed too tightly toburn off all the carbon.

Greenware does not need stilts. Load small, shortpieces directly on the firebrick bottom. If you load large,flat pieces on the firebrick bottom, place short posts un-der them for air circulation. Large, heavy pieces ofgreenware will fire best if placed across two half shelvespositioned at an even height. This allows air to circulateunder them. To make full use of the kiln’s capacity, placeware of the same height in each layer.

Fire ware in the posi-tion in which it will beused when finished, ex-cept for large pieces withflat, vertical surfaces suchas wall plaques and clocks.These should be fired flatto prevent warping. Piecesto be used together, suchas a box with its lid, shouldbe fired in place to ensurea good fit. You can alsostack mugs and bowls rimto rim.

Low-fire greenware firing is simple. Just be certain thegreenware is fired to the pyrometric cone recommendedby the clay supplier. If the greenware is not fired hotenough, the piece will absorb moisture after it has beenglaze-fired, causing the glazed surface to crack. This iscalled “crazing” and is most often due to underfiredgreenware. To help eliminate crazing, fire greenware atleast one cone hotter than glaze, and even hotter if glazecan still be applied easily to the hard bisque. While glazemay be applied to greenware and fired once, separate fir-ings produce better quality.

Peephole plugs are supplied with your kiln. See page 9for instructions on peephole plugs. Allow the kiln to coolto room temperature before opening the lid.

Loading and FiringLow-Fire Glaze

The difference between loading greenware and glazedware is that glazed pieces must not touch each other, thefloor, or a shelf in your kiln during firing. If this happensthey will be permanently bonded together and ruined bythe melted glaze.

The natural expansion and contraction of the insulat-ing firebrick during each firing generates tremendousstresses within the firing chamber. As a result, fine grainsof firebrick may form on the surface of the sidewalls andshould be removed before each firing. Wipe the sidewallswith a clean, damp cloth or vacuum the sidewalls with thesoft brush nozzle attachment of a vacuum cleaner.


Pieces to be used together, such asa box with its lid, should be fired inplace.

Use stilts to support low-fire glazed ware during firing.The shelf tops and kiln floor MUST be coated with allpurpose, high fire kiln wash for protection from glazedrops.

Glazed pieces must be thoroughly dry before firingand should not be fired with greenware unless both ma-ture at the same cone. Even then, separate the glaze fromthe greenware by loading glazed pieces in the bottom ofthe kiln and greenware on shelves above. Low-fire glazeusually fires to a lower cone than greenware, so firing timewill be shorter if glazed pieces are loaded separately.

Check to make sure that first, no two pieces of glazedware are touching each other, the kiln walls, the floor orthe shelves; and second, that the underside of the kilnshelf is clean before you place it over glazed pieces. Anydust falling on your ware will cause glaze pinholes.

To eliminate stilt marks, you can prevent glazed piecesfrom sticking to the shelf orkiln bottom by “dry foot-ing.” This is an alternativeto stilting. To dry foot apiece, remove all glaze fromthe portion of the piece thatwill rest on the shelf. Usinga wet sponge or a piece ofgrit cloth, clean off the glazefrom the bottom of the wareand slightly above the baseso that it will not run downand touch the base. Do notuse dry footing for low-fireglazed pieces that will beplaced in water while used or cleaned. The unglazed ar-eas will absorb water, which can cause glaze crazing. Thefoot ring may also turn gray.

If you are firing ware draped withlace, prop the lid with theProp-R-Vent until all smoke disap-pears.

Note: For instructions on stilts,see page 16.

Peephole plugs are supplied withyour kiln. See page 9 for instructionson peephole plugs. Allow the kiln tocool to room temperature beforeopening the lid.

Loading andFiring Overglaze

Overglaze is decoration applied over fired glaze or pol-ished porcelain bisque. Overglazes include china paints,gold, and luster, which fire from cone 022 to 014.

Load overglazed ware the same way you would load ce-ramic glaze. Use stilts and make sure ware is not touch-ing other ware. Before loading the kiln, make sure yourpieces are clean and completely dry. Remove smudges

and fingerprints from the bottom of pieces, and gentlywipe off any dust with a soft cloth.

China paints will crack or peel if applied heavily. Applyseveral light coats instead, firing between each, until youget the shade you want. Not all china paint colors reachmaximum color saturation at the same temperature evenwhen fired on the same ware. So you must know whichcolors to fire first at higher temperatures to prevent burn-ing out the original colors in later firings. For example,reds mature at a lower temperature than other colors andare fired after the other colors have been fired. Do not firereds and yellows side by side. Colors also mature at alower temperature on ceramic pieces than on porcelain orhard china. Check the overglaze manufacturer’s litera-ture for information on which cone to use with each colorand type of ware.

Fumes in the kiln will dull the colors—especially goldand lusters. Vent at low temperatures to remove thefumes. Overglaze may require extra venting with theProp-R-Vent until all smoke and odors from china paintoil and other organic materials have vanished. How longthis takes depends on how much decoration is on theware.

Note: Some artists vent throughout the entire fir-ing for best results.

Plates fire better when supported by a plate holder orplaced on edge vertically to permit even heating. If firedon edge vertically, plates may be supported at the bottomwith large spur stilts, which can also be used to separateadjoining plates. Tall posts can be used to prevent platesfrom touching the kiln wall.

Plates, tiles, and ware with uneven thicknesses maycrack when fired directly on a kiln shelf or kiln bottom.This is because the sections that touch the shelf arecooler than the rest of the piece. To prevent cracking,place a stilt under the piece to lift it off the shelf.

You can use stiltsto separate a stack ofhorizontal plates.Place a three-pointstilt under the bot-tom plate and be-tween each platestacked on top. Linethe stilts up verti-cally. Be careful notto scratch thepainted surfaces ofthe plates with the stilts. You can use this technique tostack several plates.

Caution: Do not stilt soft glazed pieces. Test ifyou are not sure.

Overglazes can usually be fired and cooled rapidly.The exception is pieces with uneven thicknesses, such asa vase with thin walls and a thick base. In general, firechina paints 2 - 2 ½ hours.


To “dry foot” a piece, remove allglaze from the portion of the piecethat will rest on the shelf.

Prop the lid in the ex-tended position whenfiring ware draped withlace. Lower the lid whenall smoke disappears.

You can use stilts to separate a stack of hor-izontal plates. But do not stilt soft glazedpieces. Test if you are not sure.

Note: Some artists find that slow firing helpsbring out the full color of china paints.

Note: Try adding a 20-minute “hold” or “soak” tothe end of a china paint firing. Some artists findthat this improves color saturation. (Switch oper-ated kilns: Use a pyrometer and adjust theswitches to hold the temperature.)

Allow the kiln to cool to room temperature beforeopening the lid.

Loading and FiringCeramic and Glass Decals

You can fire ceramic or glass decals in any kiln that canreach 1450°F (787°C). Decals are an excellent beginner’sproject, because you can achieve success with your firstfiring. You can fire decals onto glazed ceramic cups, tiles,light switches, photo frames, and much more. See yourlocal ceramic supplier for blank ceramic ware and the de-cals to fire on them.

Don’t worry if you ruin the first few decals. Applyingthem takes practice. Before starting, clean the ceramic orglass piece with water.

1 Cut out the decal andsoak in lukewarmwater until you canslide the image fromthe paper backingonto the ware. Slidethe image off thebacking rather thanattempting to lift theimage off.

2 Position the decal onthe ceramic or glasspiece. The side ofthe decal that was down on the paper is the sameside that goes down on the ceramic or glass.

3 Use a damp spongeor rubber squeegeeto squeeze out airbubbles and waterfrom the decal. Forflat surfaces, use arubber squeegee; forcurved surfaces, usea damp sponge.

4 Dry the ceramic orglass piece overnightbefore firing.

5 Fire a glazed ceramic blank on a stilt. Glazedpieces must not touch each other. Fire glass di-rectly on a kiln shelf. The shelf must be coatedwith kiln wash.

6 Fire in a well ventilated area. Keep the top ventplug out during the first hour or until the smokeand odor disappear.

7 Fire at a rate of 500°F (275°C) to the recom-mended temperature for the decal you pur-chased. Most decals fire to cone 015 - 018.

8 After the kiln shuts off, leave the lid or door closeduntil the kiln cools to room temperature.

Loading and FiringPorcelain Greenware

Porcelain greenware refers to clay bodies that matureat a point between cones 4 to 10. Porcelain is vitreous, andthe white color will usually show the shadow of the hand ifheld up to a strong light.

Note: Porcelain greenware is very fragile. You willhave an easier time cleaning it by soft-firing it tocone 018. At this temperature the ware is still softenough to clean yet not as fragile as greenware.

Loading porcelain greenware is similar to loadingglazed ware, since both will stick to anything during fir-ing. Greenware must be completely dry before firing, in-cluding the joints on pieces that are attached. If a piece isbroken before firing, mend the break but do not attemptto fire it until the mend is also bone dry. Damp greenwareor damp mended areas will form bumps on the surface ofthe fired ware.

Stilts CANNOT be used to support porcelaingreenware. They would embed into the porcelain at hightemperatures. To protect porcelain from sticking to theshelves or kiln floor, apply a coat of high fire kiln wash tothe shelf tops and brick bottom. Then place your ware di-rectly on the kiln-washed surfaces.

Caution: Never use a low-temperature ceramickiln wash in a kiln that will ever be fired to porce-lain temperatures, as the ceramic kiln wash willharden at high temperatures and be impossibleto remove.

Pieces of ware that are to be used together must befired together, such as a box and its lid. Dry high fire kilnwash can be used to separate these pieces during firing.Wet kiln wash would be too difficult to remove.


Slide the decal off the paper back-ing.

Squeeze out air bubbles and waterfrom the decal.

Pieces likely to warp in firing should be supported byrolls of porcelain clay shaped to fit the objects at points ofstrain. Apply dry silica or high fire kiln wash to the pointsof contact to prevent sticking. Before firing, the supportrolls must also be bone dry.

Since a kiln isslightly hotter near itssidewalls, the side ofthe ware next to thewalls will tend toshrink more than theopposite side. This canbe used to your advan-tage with porcelain fig-urines that tend towarp during firing.Turn the inclined sideof the figure away fromthe elements so theheat can help hold thepiece straight.

Make sure cones onthe shelf are clearlyvisible. At porcelaintemperatures, they are difficult to see. It is not necessaryto use peephole plugs. If you decide to use them, leavethem out until the firing is half over. If you are firing waredraped with lace, you may need to vent the lid with theProp-R-Vent. Lower the lid fully after all smokedisappears.

Peephole plugs are supplied with your kiln. See page 9for instructions on peephole plugs. Allow the kiln to coolto room temperature before opening the lid.

Loading and FiringPorcelain Glaze

Loading porcelain glaze is similar to loading porcelaingreenware. For good heat circulation, keep the ware atleast ¾" from the sidewalls.

Porcelain pieces thathave been fired togetherin the greenware firingcannot be fired togetherin the glaze firing. Bothpieces must be dryfooted. Since shrinkagehas already occurred inthe greenware firing,the pieces will still fiteven when fired sepa-rately in the porcelainglaze firing. Stilts mustnot be used to supportporcelain. Porcelainsoftens during firing,and stilts would embedinto porcelain. Makesure your shelves andkiln bottom have a goodcoat of kiln wash before firing porcelain.

If a piece of ware had to be supported in the porcelainbisque fire, it will stand alone in the glaze fire. The lowertemperature will prevent sagging.

Peephole plugs are supplied with your kiln. See page 9for instructions on peephole plugs. Allow the kiln to coolto room temperature before opening the lid. Cooling timeis usually twice the firing time.

Loading and FiringStoneware Greenwareor Glaze

Stoneware is made from vitrifiable clays with a firingrange of cone 2 to 10. It has a wide range of colors and tex-tures and is popular with the potter because of its excel-lent throwing qualities. Usually the greenware is fired be-low maturity to cone 04 - 06, and on the second firing, theclay and glaze mature together to form an integratedbody-glaze surface.

Like porcelain greenware, stoneware is placed directlyupon the kiln-washed shelves in the greenware firing.Place small items on the kiln bottom and large, heavypieces across two half shelves.

Glazed stoneware must not touch any other ware andmust be dry footed before you place it on a kiln-washedshelf or kiln bottom. Never stilt stoneware during eitherfiring.


Turn the inclined side of the figure awayfrom the elements so the heat can helphold the piece straight.

You can support delicate porcelainwith wads of ceramic fiber.

Rolls of porcelain clay are usedhere to support a delicate piece.

To dry foot a piece, remove all glazefrom the portion of the piece that will reston the shelf.

“I used to have this wonderful haiku pinnedup above my kiln when I had my studio:

“‘Now that my house has burned down, I havea better view of the rising moon.’

“During firing, I would lose stuff that I hadmade. Things I thought would be beautifulturned out ugly. The haiku helped me realizethat I had to live with loss and ‘failure’ and learnfrom it.”

—Sandra Dwiggins

IMPERFECTIONSKeep detailed records of your firings. This will help

you solve imperfections in the ware. The best way to pre-vent imperfections is to test glazes and clays. Use either asmall test kiln, or place test pieces in a kiln load whereveryou can find an empty spot on a shelf. Test every newbatch of clay.

GeneralBreakage or cracks Sometimes the ware breaks days

or weeks after it was fired. Causes are a poor “fit” be-tween the clay and the glaze, firing too rapidly, cooling toorapidly, removing the ware from the kiln before the kilnhas cooled to room temperature, and different thick-nesses in the ware (i.e. a cup with thin walls and thick bot-tom).

Some clays are prone to cracking no matter how theyare thrown or fired. Experiment with different clays tofind one less prone to cracking.

To cool slowly:

Digital controllers: Program a slow cooling.

Switch-operated kilns: Turn the kiln on Low for anhour at 1000°F (537°C) during the cooling cycle.

Large platters can crack during firing if they are placeddirectly on the kiln shelf. This is because the section thatis in contact with the shelf heats and cools at a differentrate than the rest of the piece. To separate the piece fromthe shelf, place the piece on small mounds of alumina hy-drate, small squares of firebricks, or thin coils of clay.(Roll the coils of clay in your hand to the thickness of apencil. Press the ware down onto the coils while the coilsare still pliable. This separates the ware from the shelves,which are thicker and therefore heat and cool more slowlythan the ware. The part of the ware that is in direct con-tact with the shelf remains hotter or cooler than the restof the piece.)

Place large flat items in the center of the shelf so thatthey receive more even heating than they would get whenplaced on the outside edge of a shelf.

Try firing to a higher temperature in the bisque firing.This strengthens the ware.

Note: Only vitrified ware should be used in a mi-crowave oven. (Vitrified clay has been fired to apoint where the particles become glass-like andno longer absorb water.) Non-vitrified clay suchas earthenware is generally not suitable for mi-crowave use, because the clay absorbs water. Thewater in the pores of the clay can expand rapidlyenough in a microwave to cause the ware to crackor even explode.

BisqueWarped ware can be caused by distorting upon re-

moval of the piece from the mold, firing too close to theelements, firing a piece in an unnatural position, or firingon warped shelves. To prevent porcelain cups or bowlsfrom warping when firing the greenware, edge the top of acup with pinches of dry silica or DRY all purpose, highfire kiln wash and place a second cup on top of the firstcup, lip to lip, with handles going in opposite directions.Porcelain greenware plates may require firing in platesaggers to prevent warping during firing.

Explosions The greenware contained moisture thatreached the boiling point. Dry the greenware more thor-oughly before firing; allow moisture to escape the warebefore firing hotter than 200°F (93°C). Can also becaused by trapped air inside the clay.

Sagging ware is usually the result of overfiring. Por-celain objects can sag if not properly supported duringfiring.

Black coring Whenyou break a piece ofware, a black line thatappears down the centerof the clay’s cross sec-tion is called black cor-ing. The carbon burnedout of the clay surfacesbut not all the waythrough the cross sec-tion of the clay. Vent longer; fire more slowly to give thecarbon more time to burn out.

Bloating If the ware is fired too rapidly during the be-ginning stages, the outside of the clay will become plasticbefore the gases have a chance to escape. This seals in thegases. Gases that escape too rapidly cause the clay to be-come bloated. Slow down thefiring, or fire the bisque a littlehotter.

GlazeCrazing appears as a net-

work of tiny cracks in the glaze.To check the ware for crazing,dab the ink from a fountain pen


Place rolled strands of clay underlarge platters or plates.

Separating the plate from the shelfhelps to prevent cracking of theware.

To prevent black coring, vent longer orfire more slowly.

onto the ware or examine it under a magnifying glass.Crazing is caused by a poor “fit” between the clay andglaze resulting in more shrinkage of the glaze than theclay during cooling. One of the signs of crazing is the faintplinking noise from the ware as it cools. Removing theware before the kiln has cooled to room temperature canaccelerate crazing. Find a better clay/glaze combination.You might also try a thinner application of glaze or fire thebisque to a higher temperature. Crazing in spots can becaused by not having mixed the glaze thoroughly beforeusing.

Delayed crazing is sometimes caused by moisturethat absorbs into the ware. This is seen in low-fire,non-vitreous clays.

Discolored glaze or variation in colors Placingware too close to a heating element can cause discolor-ation on the side that faces the element. Glaze of onecolor can affect the glaze of another color when ware isplaced too close together in the kiln. Firing rapidly canalso cause uneven colors, because the inside of vesselscool at a different rate than the outside. Slowing the firinggives these surfaces more time to become even in tem-perature. Other causes are insufficient venting duringthe early stages of firing or overfiring glazes in the redfamily.

Glaze too thin in spots can be caused by unevenglazing or a “hard spot” on low-fired bisque. Ceramicglaze should be applied in flowing coats; first in one di-rection and the next coat in an opposite direction (hori-zontal, then vertical or vice versa). Allow the glaze to drybetween each coat. Some glazes may require twice therecommended coats because of thin application. Porce-lain glaze should be sprayed or a brush-on type used.Hard spots are sometimes the first spot where the pouredslip touches the mold. Heating bisque in an oven to ap-proximately 120°F (49°C) will help in applying glaze tohard bisque.

Black specks in the ware are usually caused by or-ganic materials not completely burned out in the bisquefiring. This works its way to the surface during the glazefiring.

Pinholes and bubbles in glaze Carbon that did notburn out during the greenware firing is released duringthe glaze firing. Escaping gases rupture the glazed sur-face, causing bubbles and pinholes. Firing the glaze toofast may also cause this. Soak or slow down the kiln nearthe end of the firing. This gives the glaze more time toheal any bubbles that have formed. Pinholes or bubblescan also be caused by too heavy a glaze application, by se-

vere underfiring, or by dust on the bisque. Vacuum thekiln before firing a glaze load. Wipe dust from the under-side of shelves before loading into the kiln. You can some-times break the bubbles, fill in the craters with glaze, andrefire the piece.

Light edges on dark glass glaze pieces may becaused by the flow of the glaze away from the edges in twodirections. Try an extra coat of glaze on the edges, or ap-ply a thin coat of underglaze in the following manner: Mix1 part water with 2 parts of suitable dark or blackunderglaze and brush a thin wash coat of the underglazeover the bisque ware. Then, immediately apply the firstregular coat of full strength glaze. Allow to dry thoroughlybetween coats. Continue with the number of coats rec-ommended by the manufacturer.Crawling or bare spots on a fired piece can be causedby applying the glaze tooheavily. Oil from your skinthat gets on the greenwarebefore it is fired can alsocause this. Crawling may becorrected by applying moreglaze to these spots andrefiring.

Shivering The clay hascontracted more than theglaze causing the glaze toflake off. Reformulate theclay or glaze for a better “fit.

Running glaze Apply a thinner coat, fire to a lowertemperature, or reformulate the glaze. Some glazes, suchas crystalline glaze, almost always run. You can protectthe kiln shelf by placing a flat, thin, circular slab of clayunder the piece to catch the running glaze. Coat the clay“coaster” with kiln wash.

UnderglazeStreaks in underglaze are usually caused by not ap-

plying enough coats to the greenware. After a piece hasbeen decorated with underglaze and fired, you can checkit for streaks by submerging it in water and immediatelyremoving it. The piece will appear glossy, just as if it hadbeen glazed, and streaks and thin spots will show up. Theweak spots can be touched up and refired. Be sure theunderglaze has been fired before putting it under water.For interesting designs, underglaze colors may be ap-plied over unfired matte or texture glazes that do not flow.

OverglazeBreaking during overglaze firing can be caused by

poorly fired bisque. A slow bisque fire is always better forware that is to be china painted. The greenware should becompletely dry before being placed in the kiln. Standingplates on edge or using a plate holder gives good heat cir-culation and will help prevent plate breakage.

Purple spots in gold are usually due to a thin applica-tion of gold or too much thinner. If gold is applied acci-

Fire only in a well ventilated area! 35Glaze craters. Glaze pinholes.

Glaze crawling.

dentally to an area and then removed, it will show purpleafter being fired unless cleaned with a good gold remover.

Dull gold is caused by inadequate venting.Broken lines in gold can be caused by overfiring or

too heavy an application. However, this is can be very at-tractive when gold is crackled over a dark color of firedglaze.

Peeling china paint can be caused by applying thepaint too heavily.

Loss of color in china painting is usually a result ofoverfiring or thinning your paint with too much mediumwhen applying.

Faded colors in overglaze decals are a result of ei-ther underfiring or overfiring. If pinks and reds are drab,refire to a hotter cone. When used with a china paintbackground, apply and fire the decals first, then chinapaint and fire again. Check the decal supplier’s recom-mendations. If the decal was underfired, refire to theproper firing cone. If the decal was overfired, the designmay be repainted in china paints and refired.

Blank spots in decals are caused by air bubbles un-der the decal. Make sure the piece is clean and smoothbefore applying the decal and that excess water has beenremoved from under the decal.

Weakening of luster colors can be caused byoverfiring. White spots in lusters or metals can be causedby moisture on the ware before it was placed in the kiln orfrom having been fired at the same time as other over-glazes. Apply lusters only on a dry day.

Powdering of luster colors can be caused by tooheavy an application.

PorcelainBumps in porcelain are usually caused by firing wet

greenware or by overfiring the porcelain bisque.Lack of translucency in porcelain can be caused by

pouring the ware too thick or underfiring.Cracks in porcelain bisque are often the result of a

strain on the greenware while drying. Do not force-drygreenware. Cracks may be mended with one of themenders available from your supplier.

Holes in lace or fabric that appear after firing can becaused by inadequate application of the slip. Wash thefabric thoroughly before dipping it into the slip. Applyenough slip to the fabric so the clay will be strong enoughto hold its own weight. The fabric must burn out beforethe clay matures, leaving only the clay shell, which mustbe strong enough to support its own weight.

Gray marks are caused by moisture trapped in por-celain during the porcelain bisque firing. This is calledmildew. Vent moisture from the ware, and fire the porce-lain to full maturity.

KILNMAINTENANCE

Note: This section includes removing the switchbox and changing elements. For instructions onreplacing switch box components, see the sepa-rate switch or controller instruction manual thatcame with your kiln.

How to Open theSwitch Box

Note: The switch box is the metal housing thatcovers the element connectors and holds theelectrical components such as switches or thedigital controller.

Caution: Whenever you turn off the circuitbreaker to your kiln, tape the breaker box doorshut and leave a note saying, “WORKING ONKILN. BREAKER OFF.”

The Non-Hinged Box1 Disconnect the power to

the kiln.

2 Remove and save thescrews at the side of theswitch box that hold it tothe kiln.

3 Remove the box, pullingstraight out to avoid dam-aging the Kiln Sitter porce-lain tube (if any). You mayneed to prop the switch box on a chair, woodenbox, or other object as you lean the switch boxagainst the kiln.

The Hinged Drop Box

Note: Your switch box ishinged if it has a folding armon the side of the box.

1 Disconnect the power tothe kiln.

2 Remove the top two screwsof the switch box. The boxwill open forward.

3 Opening the switch boxwill show the elementcover. To gain access to theelements, remove thescrews on the sides of theelement cover. Lift out theelement cover.


Preventive MaintenanceInside the Switch Box

The best time to perform preventive maintenance iswhen you have opened the kiln’s switch box to change el-ements or other parts.

1 Dust can cause components in the switch box tooverheat, because dust acts as an insulator. When-ever you open the switchbox, blow out the dust withcanned air. (It is availablefrom computer stores oreven Wal-Mart.) Wear afacemask. Do not hold thecanned air upside down, andnever spray yourself. (Theair gets cold enough tocause injury.) Hold the airnozzle 6" away from theparts you are spraying.

Note: You could also use avacuum cleaner and a dry paintbrush to clean theswitch box of switch-operated kilns. But we donot recommend them for cleaning the switch boxof digital kilns. They can create a static chargethat could damage the electronic controller.

2 Examine the wires in the switch box. Use a flash-light if lighting is dim. After decades of heat, theinsulation on wires becomes brittle. Signs of aginginsulation are white wires that are brownish andcolored wires that are fading. When you bendwires, do you hear or feel the insulation cracking?When insulation cracks off the wires, it is alsolikely that strands of wire are breaking, too, whichcan raise the resistance and cause the wires tooverheat. Replace damaged wires.

Note: Do not use electrical tape to repair wiringinside a kiln switch box.

3 Check the wire termi-nals for tightness.Squeeze loose push-onterminals with pliers totighten. Replace termi-nals that are loose due toheat damage.

4 Check the element con-nectors for corrosion,which will turn the con-nectors white or green.Corrosion is usually dueto a loose screw holding the connector and some-times due to a loose wire terminal. A loose elementconnector will slow the firing, even if the elementitself is okay. Tighten corroded element connec-tors if they are loose.

5 As you reinstall the switch box, arrange the wiresso that when the switch box is placed against thekiln, no wire touches an element connector or thekiln case. These get hot enough to eventually burnoff wire insulation, which could cause a short cir-cuit.

Element MaintenanceHow to Get theLongest Life Out ofYour Elements

The elements in your Para-gon kiln should last for manyyears of normal use. Withtime, however, the elementsgradually draw less power, andfirings take longer. Elementsshould be replaced when firing time becomes excessive.Record the firing times in a firing logbook.

Note: Before you replace the elements, be surethat excessive firing times are not due to low volt-age. Sometimes the voltage drops temporarilyduring periods of heavy electrical demand.

High temperature elements are damaged by contactwith silica or silica bearing compounds, such as glaze andkiln wash. If silica touches an element, the element willburn out during the next firing. This type of damage isnot covered by warranty.

Also, reduction firing, which removes the oxygen fromyour kiln, will ruin your elements. The elements are pro-tected by a coating of oxidation, which reduction firingdestroys. Reduction is performed at your own risk; ele-ments damaged by reduction are not covered by warranty.

All heating element wires change in length with use.This is an inherent characteristic that metallurgical sci-ence has never found a way to control. This change cancause elements to shrink away from the corners andbulge outside the grooves into the kiln. At porcelain tem-


Removing the element cover togain access to the element connec-tors. Not all kilns have an elementcover.

Cleaning the switch box withcanned air.

Squeeze a loose connector totighten, but replace connectorsthat have been damaged by heat.

peratures, however, elements become quite soft and willnot support their own weight. During high temperaturefiring, the elements soften to conform to the shape oftheir grooves.

If you never fire hotter than cone 05, the element neverbecomes soft enough to conformto the grooves, so bulging may oc-cur. If you do not fire hotter than05 and you are having a problemwith bulging elements, you maywant to pin the elements in placeas follows:

1 Disconnect the power fromthe kiln. Whenever you turnoff the circuit breaker to yourkiln, tape the breaker boxdoor shut and leave a notesaying, “WORKING ONKILN. BREAKER OFF.”

2 Cut a Paragon element staplein half at an angle to leave asharp point. (Use only ele-ment staples; do not use asubstitute staple from ahardware store.)

3 Bend about 316" at a right angle.

4 Grasp the bent portion with pliers and push itthrough the lip of the groove at a slight angle.The pin must go over the bottom of the turn inthe element coil, holding it against the bottom ofthe groove.

Alternate MethodPush a straight piece of element staple wire, cut at an

angle, over a turn of wire and into the back of the groove.This method does not fasten the element as securely asthe above method. Its only advantage is neater appear-ance.

If you check to make sure the elements are seatedwhen you set up your new kiln, and if you fire your kiln tocone 05 or hotter occasionally, your elements will proba-bly stay in their grooves throughout their life. Should theelements start to bulge out of the grooves, they must bereseated immediately.

Reseating a Bulging ElementOnce an element has been fired, it becomes brittle and

will break if it is bent while cold. Follow this procedure toheat the element.

1 Always unplug the kiln or disconnect the powerbefore touching the element with anything!Whenever you turn off the circuit breaker to yourkiln, tape the breaker box door shut and leave anote saying, “WORKING ON KILN. BREAKEROFF.”

2 Heat the elementwith a propanetorch until the el-ement is red hot.Press the igniterand hold theflame near thebulging element.You will see theelement turn redin just a few sec-onds. Then re-lease thep u s h - b u t t o nigniter.

Note: You can purchase a propane torch from ahome improvement center. Buy the type that hasa push-button igniter. A blue flame appears whenyou press the button. The flame goes out whenyou release the button. For element mainte-nance, do not use the older manual propanetorches that have the twist knob. Turning themon and off is awkward when working on elements.

3 With a pair of long nosed pliers (dime store qual-ity will work fine), shrink the bulging portion ofthe element by pressing the individual turns inthe coils together slightly. Take a little from eachturn so that no two turns are pressed tightlyenough to touch.

4 As the element shrinks, work it back toward thegroove and into place. Work rapidly, and at thefirst sign of stiffness in the coils, stop bendingand reheat the kiln. The elements do not have tobe red to be bent safely, as the stiffening can befelt through the pliers.


In addition to the two methods shown in the diagram above,you can also pin an element with a J-shaped pin.

Using a propane torch with push buttonigniter to heat a bulging element.

5 To lengthen the element tofit into the corners, reversethe above procedure andexpand the distance be-tween coils by usingsnap-ring pliers. Use cau-tion, as your warranty cov-ers elements that fail onlyin service under normal useand not from being brokenwhile cold.

Note: You can purchasesnap-ring pliers from an automotive parts store.

6 When you have the coils positioned above thedropped recess in the grooves, reheat the elementsection and run a blunt kitchen knife around theelements to seat them into the grooves.

Note: Do not use a plastic object, such as a comb,to press hot elements into their grooves. Meltedplastic ruins elements.

7 Fire the kiln to cone 01 or hotter to soften the ele-ments completely.

How to Test for a Burned Out Element

Method One: The Newspaper Test

1 With the kiln turned off, place a small strip ofnewspaper in each element groove so the newspa-per touches an element.

2 Turn on the kiln. Within 10 minutes, the elementsshould get hot enough to scorch the newspaperthat is in each groove.

Method Two: The Ohmmeter Test

How to Use an OhmmeterAn ohmmeter is an inexpensive aid in determining if

an element is broken. The ohmmeter measures the elec-trical resistance of a wire in ohms. The higher the ohms,the greater the resistance. As an element ages, the resis-tance increases, and the ohms reading becomes higher.

There are two types of ohmmeters: needle indicator(analog), and digital. Ohmmeters have two probes. Whenyou touch the probes together, the analog ohmmeter nee-dle should move all the way over. A digital meter shouldread zero ohms.

Q The kiln should be unplugged before touchingthe ohmmeter to the element. So, how does theohmmeter check the element if the kiln is notplugged in?

A The ohmmeter contains a battery that sends asmall electric current through the element. If theelement is broken, the electricity cannot make acomplete circuit back to the ohmmeter. If the el-ement is not broken, the ohmmeter reads theelectrical resistance in the element.

Note: You can test the elements with an ohmme-ter or a simple battery-operated continuity testeravailable from auto parts stores. The light comeson if the element is good.

To test an element, find the ohms for that elementfrom the kiln’s wiring diagram. If an ohmmeter test givesa resistance that is close to the correct resistance, the ele-ment is not broken.

The center elements of most current Paragon kilnsare cooler elements than the top and bottom ones. Thesecooler elements do not glow until the kiln has fired forsome time. Also, some Paragon kilns have elements wiredin series. Elements wired in series with a burned out ele-ment all stop firing. So you can’t always tell which ele-ment is firing by turning the kiln on, opening the lid, andwatching for elements that turn red. With an ohmmeter,however, you can find a burned out element in anyParagon kiln.

Note: When an element breaks, it should no lon-ger be able to carry electricity. Sometimes, how-ever, a broken element will show continuity whentested with an ohmmeter or a continuity tester,because as the element cools, in rare cases thebroken ends touch. Thus, electricity can stilltravel through the element. Yet when you fire thekiln, the element will produce little, if any, heat. Ifyou suspect that the element is burned out eventhough you are still obtaining a resistance read-ing, check the element grooves with a flashlight.You should be able to see the break.

Note: If an element burns out, the kiln will eithernot heat up or will fire to a drastically lower tem-perature. If the elements are wearing out, theywill gradually take longer to fire until they can nolonger reach the temperatures you normally fireto.

1 The kiln should be cold when you test the ele-ments. UNPLUG the kiln or disconnect thepower before removing the switch box or touchingelements. Whenever you turn off the circuitbreaker to your kiln, tape the breaker box doorshut and leave a note saying, “WORKING ONKILN. BREAKER OFF.”

2 The element connectors are covered by a switchbox, which is usually on the front of the kiln. Re-move the screws holding the switch box to the kiln.Remove or open the switch box. See “How to Openthe Switch Box,” page 36.

3 You will see two connectors for each element.There is no need to remove the lead wires fromthe connectors provided you have only one insu-lated lead wire attached to each element connec-tor. If you have more than one lead wire on eachconnector, your elements are wired in series/par-allel. In that case, temporarily remove the wires


from one of the connectors. Otherwise currentfrom the ohmmeter battery can pass throughother elements than the one you are testing,causing an incorrect reading. Hold the elementconnector with locking pliers as you remove thescrew. Be gentle to avoid breaking the element.(Elements are brittle after being fired.) Do notdisturb the screw holding the element, only theone holding the lead wires. Reconnect the wiressecurely after testing the element.

4 Touch the ohmmeter leads to the two connectorsof the element you are testing. You may need toclean a spot on the connectors to get a good elec-trical contact. For best results, touch the probesto the element connectors and not to the twistedelement ends.

A burned out element will show as infinity ohmson a digital meter or no needle movement on ananalog meter.

A worn out element is roughly 10 percent higherin ohms than a new element. (See your kiln’s wir-ing diagram for the ohms of the elements in yourkiln.) However, if your ohm readings are high,that does not always mean the elements are wornout. Your meter may be inaccurate. A better indi-cation of element wear is the length of firingtime. As the elements age, the firing time willgradually become longer.

5 As you move the switch box back into place, makesure no wire touches the kiln case or elementconnectors. Wires touching the case or elementconnectors will burn.

How to Repair a BurnedOut Element Connector

When an element burns out at the connector, you maybe able to install a new connector and salvage the ele-ment.

This type of failure is due to a loose connection, whichbuilds up enough heat in the connector to break the ele-ment wire. This is why it is important to securely tightenelement connectors when replacing an element.

1 UNPLUG the kiln or disconnect the power be-fore removing the switch box or touching ele-ments. Whenever you turn off the circuit breakerto your kiln, tape the breaker box door shut andleave a note saying, “WORKING ON KILN.BREAKER OFF.”

2 Open the switch box (see “How to Open theSwitch Box,” page 36). You will see two elementconnectors for each element in your kiln. If theelement has burned at the connector, you willusually see a bare, twisted section of elementwith a missing connector. This is because the el-ement connector has fallen off the broken ele-ment end.

3 Does the burned element end have ½" of lengthso that you can install another element connec-tor? If not, gently and slowly pull the element endwith needle-nose pliers. There is sometimesplay in the element, which you will feel as you pullthe element end toward you.

Note: If necessary, heat the element where it en-ters the firing chamber. Use a propane torch asshown on page 38. This will allow you to stretchthe element slightly to gain extra length.

With ½" of exposed element length, you can in-stall a new element connector. Do not removethe porcelain insulator located under the ele-ment. Removing the insulator would give you ex-tra element length, but the insulator is there toprevent the element from shorting out againstthe case.

4 Clean the end of the element pigtail before in-stalling the new connector. Do not attempt to re-use the old connector. Always use a new one.Check the element lead wire for heat damage. Ifthe insulation is brittle, replace the wire.

5 Use the stainlessscrew in the elementconnector to holdthe element. (Thebrass screw holdsthe lead wire eyelet.)Hold the barrel ofthe connector withlocking pliers (notregular pliers) asyou tighten thescrew with a ¼" nut driver. Tighten the hex-headscrew to 30 inch pounds (about 1 ¼ turns pastthe point of firm resistance).

Note: If, when tightening the element connector,you feel the threads strip out, remove the connec-tor and install another. A connector with strippedthreads will burn out. Suppose the head of thescrew or bolt on the element connector twists


Tightening the element connector.

off? That’s okay as long as the threads are stillholding.

Tightening the Connectoron an APM Element

APM heating elements are made from powderedmetal. They last longer than standard element wire andare recommended for cone 6 and hotter firings.

APM elements install the same way as standard ele-ments shown below, except for the element connectors.To install the connectors properly, insert the twisted wireend through the hole in the connector. Then rotate theconnector until the screw presses against two twistedstrands of wire. If the screw presses against only onestrand of wire, the connector can become loose. BecauseAPM wire is harder than standard element wire, the ele-ment screws need more metal to bite into.

How to Replace an Element

Q Should you replace all the elements at thesame time?

A If one element breaks due to contaminationwith a foreign material such as kiln wash, replaceonly that element. If the elements are at the endof a wear cycle, and you need to replace a brokenone, replace them all.

No mechanical skill is necessary to install Paragon re-placement elements. However, your local Paragon dealerwill install the element for you at a reasonable charge. Ifyou do not have a local dealer, see your appliance shop re-pairman. He is more experienced in servicing heatingdevices than an electrician.

Note: You can find a list of kiln technicians atwww.paragonweb.com. Select “Support” andthen “Kiln Technicians” from the drop menu.

Paragon replacement elements are formed to theshape of the kiln at the factory. However, a little stretchingor compressing may be necessary for a perfect fit. It issafe to bend and stretch new elements before they havebeen fired, but once fired and allowed to cool, elementsbecome brittle and will break if bent.

Note: Some of our employees wear thin cottongloves while installing elements. This is a goodidea. Make sure the gloves are clean. Flakes ofkiln wash can transfer from the gloves to the newelements, which can cause premature elementfailure. So do not wear the cotton gloves to handleelements if the gloves have also been used to wipekiln wash from glazed ceramics.

Q. Can oils from your hands damage a newelement?

A. Oils will burn off harmlessly the first time youfire the element. Salts can damage an element.However, the amount of salt on the hands is so

small that it would have no effect on element life.But do not allow kiln wash to touch a newelement.

If a top/bottom element is reversed with a center ele-ment, the kiln will fire unevenly. So when you receive anew set of elements, check the element labels. Install ele-ments marked TOP/BOTTOM and CENTER in thecorrect locations. (Some kilns, though, use only one typeof element throughout the firing chamber.)

Caution: Install the Paragon replacement ele-ments designed for your model. Do not installnon-standard higher amperage elements. Theycould cause a fire hazard.

1 UNPLUG or disconnect the kiln and allow it tocool to room temperature.

Caution: Whenever you turn off the circuitbreaker to your kiln, tape the breaker box doorshut and leave a note saying, “WORKING ONKILN. BREAKER OFF.”

2 Remove the screws on the switch box and open thebox. See “How To Open the Switch Box,” page 36.

3 With a ¼" nut driver, remove the screws in the ele-ment connectors that hold the element lead wiresto the element you are replacing. Hold the connec-tors with locking pliers as you loosen the screws.

4 On the same connec-tors, loosen thescrews that hold theelement and throwthe old connectorsaway. Always use thenew connectors fur-nished with the newelement.

5 Remove and save theporcelain insulatorsthat were behind the element connectors.

6 Lift the old element out of the groove with a pencilor small screwdriver. Then remove the elementcarefully to prevent breaking the lip of the elementgrooves.

If the old element burned out due to contact withforeign materials, there will probably be a melted,glazed spot in the element groove. Glazed spotsleft in the grooves may ruin the new element, sodig out any of these spots. The small hole left inthe groove will not affect the new element.

7 Remove small pieces of firebrick and dust in thegrooves with a dry brush (such as a householdpaint brush) or vacuum cleaner.

8 Protect the new element from coming in contactwith kiln wash by placing newspaper on the kiln


Removing element connectors.

bottom. To keepfrom tangling upthe element, keep iton the top rim ofthe kiln’s sidewallwhen you feed itinto the grooves. (Ifyou place the ele-ment in the bottomof the kiln, the ele-ment will tangleup.) Also, arrangethe element soyou’re feeding thebottom loop firstinstead of the topone.

9 Thread the new element into the upper elementhole inside the kiln.

To guide the element through, you can look intothe hole where the porcelain insulator goes. Oryou can use the twisted end of the old element tothread the new element into the holes. To dothis, insert the end of the old element into thehole where the porcelain insulator fits until theelement appears in the firing chamber. Press theend of the new element against the end of the oldone and push the new element all the waythrough.

10 The element isbent slightlywhere it fits intoeach firebrickcorner. Thebend must fit allthe way into theback of each cor-ner. As you feedthe element,hold it with both hands in such a way that you areapplying constant pressure that pushes the ele-ment into the corners. If you let go before the ele-ment is completely threaded, it will spring backout of the corners.

After the first element bend is in its corner, dothe next corner. If the next element bend will notreach the next corner, gently stretch that sectionof element with your hands. If the element is toolong between bends, let that section of elementcurve out of the groove. Then continue threadingthe element into the other corners. When the el-ement is completely installed, go back to the sec-tion that was too long. Compress coils withlong-nose pliers until the element fits into itsgroove. No two coils should be compressedtightly enough to touch.

Remember, if you do not push the element fullyto the back of each corner, the element will notstay in the grooves when fired.

11 Press the elementdown into thelower part of thegroove with a plas-tic comb orwooden tonguedepressor.

12 Reinstall the por-celain insulators.Push them flushagainst the heat shield. They protect the elementfrom contact with the case and heat shield, sothey must not work their way out after the ele-ment connector is tightened into place.

13 Sandpaper the eyelet of the element lead wiresuntil bright and clean of all oxidation. (Installnew lead wires if the insulation on old ones isbrittle.) Use the brass screw to connect the leadwire eyelets to the new element connectors. Be-fore tightening the screw, adjust the eyelet towhere it will be tilted away from the heat shieldwhen the connector is attached to the element.Then hold the connector with locking pliers andtighten the brass screw securely with a ¼" nutdriver.

14 Pull the end of the element tight and install newelement connectors snugly against the porcelaininsulators to prevent insulators from slippingaway from the brick wall.

Use the stainless screw in the el-ement connector to hold the ele-ment. (The brass screw holdsthe lead wire eyelet.) Hold thebarrel of the connector withlocking pliers (not regular pli-ers) as you tighten the screwwith the ¼" nut driver. Tightenthe hex-head screw to 30 inch pounds (about 1 ¼turns past the point of resistance).

Note: If, when tightening the element connector,you feel the threads strip out, remove the connec-


Arranging the element so it doesn’ttangle up as you install it.

Installing the elementconnectors.

tor and install another. A connector with strippedthreads will burn out. Suppose the head of thescrew or bolt on the element connector twistsoff? That’s okay as long as the threads are stillholding.

15 Cut off the twistedend of element evenwith the side of theelement connectors.Leaving the excesselement sticking outpast the elementconnector could ruinyour new element!(The element couldshort against something in the switch box.)

16 As you move the switch box back into place, checkthat no wire touches the case or an element con-nector. Wires and wire nuts will burn if they touchthe case or element connectors. Reinstall thescrews in the switch box and tighten.

Note: Switch-operated kilns: Watch the kilnclosely the first time you fire it after installing newelements. You may need to adjust your firingschedule, because the kiln will fire faster.

Firebrick MaintenanceReplacing a Standard Lid (No LiteLid)

These instructions are for kilns not equipped with theLiteLid spring counter-balance.

Note: Drill holes with a 18" bit. Tap a mark in the

metal with a center punch or nail to start holes.Do not over-tighten screws. Stop turning whenthe screw feels snug. Wearsafety glasses when drilling.

1 Remove the nut that holds thelock-in lid support to the lid.(If your kiln is equipped withchains instead of a lid sup-port, remove chains from lid.)

2 Remove the screws from theupper lid hinge using a ¼" nutdriver. (Do not remove thelower hinge sectionfrom the kiln case.Leave hinge rod inplace.) Lift the old lidoff the kiln.

3 Gently place the newlid onto the kiln. Lineup the edges of the lidwith the sides of thekiln.

4 The hinge contains play to allow the lid to float athigh temperature. This adjusts for heat expan-sion. Lift the upper hinge half up and down, andyou will feel this play. The upper hinge must be inthe lower part of this play when you attach thehinge to the lid. Mark holes in the lid with afelt-tipped pen. Drill holes. Install screws.

5 Lift up the back of the lid.The lid should have play init. If there is no play, thefront of the lid could tilt up-ward during firing.

6 Install the upper lock-in lidsupport stud with 4 screws.Align it as in the photo atright.

7 Fasten the lid support to up-per stud with the nut re-moved earlier. (Installchains if kiln is equippedwith chains.)

8 Install the lid handle andProp-R-Vent latch.

Replacing a Lid onKilns Equipped With the LiteLid

These instructions are for 10- and 12-sided kilnsequipped with the LiteLid spring counter-balance.

Note: Drill holes with a 18" bit. Tap a mark in the

metal with a center punch or nail to start holes.Do not over-tighten screws.Stop turning when the screwfeels snug. Wear safetyglasses when drilling.

1 Raise the lid. Have someonehold the lid in its upright po-sition while you remove thetwo bolts that secure the bot-tom spring loop. With thespring pressure released,close the lid.

2 Using a ¼" nut driver, re-move all screws fasteningthe front and rear LiteLid brackets to the lid. Liftthe horizontal arm of the LiteLid up and out of theway.

3 Lift off the old lid. Gently place the new lid onto thekiln. Line up the edges of the lid with the sides ofthe kiln.

4 Lower the horizontal arm of the LiteLid onto thelid, using cardboard to protect the lid fromscratches.


Install the element connector flushagainst the porcelain insulator. Aftertightening, cut off excess length.

Install the hinge so that with the lidclosed, the rod rests in the bottom ofthe slotted hole as shown here.

5 Center theLiteLid front lidbrackets horizon-tally between thekiln wall brickseams and verti-cally between theupper and loweredges of the lid.Hold the bracket in this position while you marktwo holes for each bracket with a felt-tipped pen.Move the brackets out of the way. Drill holes.Screw the brackets onto the lid. Then drill theother holes for the brackets and install screws.

6 The LiteLid hinge hasplay in it to allow the lidto float at high tempera-tures. This adjusts forheat expansion. Lift arear lid bracket to feelthis play. The rear lidbrackets must be in thelower part of this playwhen you attach them tothe back of the lid.

In addition, thereshould be a 1

16" gap between the back of the lidand the kiln wall. This is to insure sufficientroom for expansion. Place several sheets of paperwith a total thickness of about 1

16" under the lid atthe hinge area. Then mark two holes on the lidwith a felt-tipped pen for each bracket. Drillholes and install two screws in each bracket.Then drill the other holes and install the rest ofthe screws.

7 Install the lid handlesand Prop-R-Vent latchon the new lid.

8 Have someone holdthe lid in the openposition while youattach the lowerspring loop using thetwo nuts and boltsremoved in Step 1.

Adjusting a LiteLidThat Rises in the Front

During firing, the firebricks expand and the kiln actu-ally rises, becoming taller. The lid has vertical play at thehinge that is designed to allow the lid to float. This com-pensates for the expansion of the kiln. If the lid is tight atthe hinge, the front of the lid will lift up during firing.This happens when the hinge is not adjusted properly oris binding.

If the lid rises in the front, please do not put a weight onthe lid to hold it down. That will only damage the lid. In-stead, check for binding and adjust:

1 The lid must have verti-cal play in the hinge. Tocheck for play, close thelid all the way. Havesomeone hold a sidehandle and lift the lidwhile you watch theback of the lid. You willfind a lid bracket at-tached to each side ofthe lid. The lid bracketon the side that you liftshould go up about 1

8"when someone lifts theside handle. (If you can-not lift the back of the lid, it may be due to a tighthinge bolt. See step 2.)

2 The nut on the lid hinge bolt must not be tootight. (See photo above.) Otherwise the lid canbind, causing the lid to rise in the front duringfiring. If the lid could not lift up in Step 1 above,loosen the nut on the hinge bolt. If, after loosen-ing the nut, the lid still cannot lift up, go to Step 3.

3 The lid bracket holds the back of the lid to thehinge. The hinge bolt passes through a slottedhole in each lid bracket. That slotted hole is noteasy to see, because the LiteLid rear arm coversit. But if you position yourself so the hinge bolt isat eye level, you can see the slotted hole. (See 2ndphoto from top, left column.)

With the lid closed, the hinge bolt should be atthe top of the slot in the lid bracket. If the bolt isat the bottom of the slotted hole, the lid was in-


Notice the 116" gap in the lid and

the position of the slotted hole.

Installing screws in the rear lid brackets.

To check for play in the hinge,have someone lift the back ofthe lid, or lift it with the end of ascrewdriver.

Installing the Prop-R-Vent latchonto the new lid.

Nut on hinge bolt.

stalled improperly. If this is the case, please callthe factory for additional help.

4 If the lid still rises during firing after all the abovechecks out okay, insert a screwdriver between eachrear lid bracket and rear Litelid arm. Twist thescrewdriver to ease possible binding. Or use lock-ing pliers such as Vice Grips to bend the metal toremove binding. Or bend the yoke with yourhands. When binding is removed, the lid will floatagain.

Tightening the Lid Band

The lid stainless steel band may need tightening oncea year.

1 Grasp the clamp with pliers to prevent the clampfrom twisting.

2 Tighten the screw to take up the slack in the lidband. Tighten until the screw feels snug. Try notto over-tighten.

Adding a Steel Base PlateParagon 6-, 7-, 8-, 10-, and 12-sided kilns have a galva-

nized steel base plate under the firebrick bottom. Thebase plate covers the entire bottom and has tabs that foldup inside the stainless steel case on all sides. Though thebase plate is galvanized steel, it may eventually rust espe-cially if you fire moist greenware or live near the ocean.

The easiest way to repair a rusted base is to lay a pieceof galvanized sheet metal between the kiln and kiln stand.You don’t even need to remove the old base from the kiln.

You can buy the galvanized sheet metal from a hardwarestore. It should be large enough to protect the entire kilnbottom.

Replacing the Steel BasePlate and Turning Overthe Bottom

Note: Follow “Adding a Steel Base Plate” above ifyou only need to replace the steel base but do notneed to turn the brick bottom over.

Replacing the base plate also turns the brick bottomover, giving you a fresh side. Paragon 6-, 7-, 8-, 10-, and12-sided kilns have a galvanized steel base plate under thefirebrick bottom. The base plate covers the entire bottomand folds up inside the stainless steel case on all sides.

Though the base plate is made of galvanized steel, itwill eventually rust especially if you fire moist greenwareor live near the ocean. A sign of rust is dark flecks of steelunder the kiln. (Do not replace the base plate if it has onlyminor rust.) To replace the base plate, you will need sev-eral helpers.

Non-Sectional Kilns

1 Remove the screwsthat hold the base plateto the kiln: You willfind a screw near thebottom of the kiln oneach flat side. Do notdisturb the otherscrews in the stainlesssteel case.

2 Have several people liftthe kiln. The bottomand old base plate willremain on the kiln standwhile your helpers liftthe kiln. Have your help-ers hold the kiln upwhile you work rapidly inSteps 3 and 4.


Remove screws.

3 Place a new base plate on top of the brick bottom.The bottom is now sandwiched between the newbase plate and the old one. Carefully turn thebottom over so that the new base plate is under-neath and against the kiln stand. You must usecare in turning the bottom over. If it is cracked,the bottom could separate if handled carelessly.

4 The old base plate is now on top of the brick bot-tom. Remove and discard the old base plate.

5 Lower the kilnon top of thebrick bottom.As you do this,slide the baseplate tabs up in-side the stain-less steel kilncase. Drill newholes and installthe screws thatyou removedearlier.

6 Vacuum the brick bottom. Apply kiln wash to thebrick bottom before firing the kiln.

Sectional Kilns

1 You will find a screw near the bottom of the kilnon each flat side. Those screws hold the baseplate to the kiln. Remove the screws.

2 On the kiln bottom, youwill find twist latchesthat hold the bottom tothe kiln. Remove thescrews from the lowersection of the twistlatches.

3 Have severalpeople lift thekiln. The bot-tom and oldbase plate willremain on thekiln standwhile yourhelpers lift thekiln. Gently laythe kiln onto ap r o t e c t i v esheet of card-board.

4 Place a new base plate on top of the brick bottomsliding the base plate tabs up inside the band.The bottom is now sandwiched between the newbase plate and the old one. Carefully turn thebottom over so that the new base plate is againstthe kiln stand. You must use care in turning thebottom over. If it is cracked, the bottom couldseparate if handled carelessly.

5 The old base plateis now on top ofthe brick bottom.Remove and dis-card the old baseplate.

6 Drill holes for thenew base plateand install screws.

7 Place the kiln ontop of the brickbottom.

8 Reinstall the bot-tom section of thetwist latches that were removed in Step 2 drillingnew screw holes.

9 Vacuum the brick bottom. Apply kiln wash to thebrick bottom before firing the kiln.


Place the new base plate on top of the brick bottom while your helpershold up the kiln.

Slide the tabs on the new base plate underthe stainless steel case.

The kiln with the new steel base plate.

Remove the screws that hold thetwist latches to the kiln bottom.


GLOSSARYbisque Fired, unglazed clay.

bisque firing Firing the greenwareto harden and prepare for glazing.Also called greenware firing.

cone, pyrometric A small pyramidof ceramic materials that will react tothe effect of time, temperature, andatmospheric condition inside thekiln in the same way as ceramic ware.

crazing Hairline cracks in glazedware.

crawling Bare areas where the glazedid not adhere.

decal A design or picture printed inoverglaze or underglaze colors on aprotective coating. The decal isslipped from the paper backing ontothe appropriate ware and fired forpermanency.

dry footing Removing all glaze fromthe bottom of ware before firing.This eliminates the need to stiltlow-fire ware.

earthenware Low-fired ware that isporous.

element A coil of wire that heatswhen electricity passes through it.

enamel Liquid or powder contain-ing finely ground glass. Usually ap-plied to metal, such as copper, andfired in a kiln.

glaze A liquid composed of glassparticles applied to ceramic ware.

glaze firing The bisque orgreenware firing hardens the wareand prepares it for glaze. The glazefiring melts the glaze over the clay.

greenware Unfired clay objects.

greenware firing Firing thegreenware to harden and prepare forglazing. Also called bisque firing.

heat soak Maintaining a particulartemperature inside a kiln.

hold time The length of time that atemperature is maintained inside akiln. See “heat soak.”

infinite control switch A switchthat uses a bi-metallic timer to adjustcurrent flow to the heating elements.It makes a clicking noise as thebi-metallic timer cycles on and off.When turned to HIGH, the powerflows to the elements continuously.

insulating refractory firebrickThe type of bricks used to line the in-terior of most Paragon kilns.

kiln furniture The shelves andposts used to stack ware inside a kiln.

kiln sitter A cone activated, me-chanical device to shut off the kiln atthe proper temperature.

kiln wash A powder mixed with wa-ter and brushed on top of shelves andbottom of kiln’s firing chamber asprotection from drops of fired glaze.

limit timer A Kiln Sitter with aback-up electrical power shut-off.When a clock on the Kiln Sitter runsout of time, it shuts the kiln off.

luster An iridescent overglaze,sometimes metallic.

maturing point The stage whereclay or glaze has received the correctamount of “heat work.” This is usu-ally measured by the 6 o’clock bendof a large pyrometric cone placed on akiln shelf beside the ware being fired.

overglazes China paints, lusters,gold, etc., usually used over a firedglaze but may also be applied on pol-ished porcelain bisque and fired forpermanency.

peephole The hole in the sidewall ofa kiln used to see the interior of a hotkiln.

plaster A white powder used formaking ceramic molds.

porcelain A vitrified, translucentceramic ware.

pyrometer An instrument for mea-suring temperature.

ramp Changing the temperaturewith a digital controller. If the tem-perature change is drawn in graphform, the resulting line looks like aramp.

relay A switch triggered by an elec-tromagnet. A digital controller sendspower to the electromagnet, whichcloses a switch that turns on theheating elements.

segment A set of programmed in-structions for the digital controller inthe Ramp-Hold mode. A segmentchanges firing speed, temperature,and can add hold time.

silica A mineral that will not hardenat a very high firing temperature,used for separating porcelaingreenware during firing.

slip A liquid clay used in making ce-ramic objects by casting.

stilts Small clay- or metal-tippedsupports used to prevent glazed ob-jects from sticking to the kiln orshelf.

stoneware A vitreous ceramic bodyusually made from native clays.

thermal shock Stress caused bysudden changes in the temperatureof ceramic ware. Can cause cracks orbreaks.

thermocouple The measuring unitof a pyrometer that is inserted intothe kiln’s firing chamber.

transformer An electrical device inthe kiln’s switch box that changes thehigher voltage from the wall outlet to24 volts. The lower voltage powersthe digital controller.

underglaze A decoration applied togreenware or bisque, usually appliedunder the glaze.

venting At the beginning of the fir-ing, allowing air to come into the kilnand vapor and gases to escape. Thisis one of the most important steps infiring.

vitrify To change into a glassy or anon-porous state by heat and fusion.Vitreous clay is strong and water-proof. It makes a ringing sound whenstruck.


INDEXA

alarm clock, 5alumina hydrate, 20 - 21aluminum wire, 9APM heating elements, 41

B

base plate, 18, 45bead rods, 17, 24bisque, 18, 28black coring, 34bloating, 25 - 26, 34bubbles, glaze, 26, 35buzzing noise, 30

C

candling, 18, 27cement, 5china paint, 31, 36circuit, 8 - 9circuit breaker, 4 - 5, 8clicking noise, 2, 7, 29clothes dryer circuit, 9convection, 23cooling, 27, 34cordset, 4 - 5, 7cracking ware, 34cracks, firebrick, 2cratering, 25crawling, 35crazing, 25 - 26, 28, 30 - 31, 34

D

decals, 32, 36downdraft vent, 18, 23, 26, 28, 29dry footing, 31, 33drying, 29

E

earthenware, 5element connectors, 37, 40elements, 7, 9, 14, 17, 19, 20, 29, 36 -37 - 39, 41extension cord, 4

F

fan, 6 - 7, 20, 26, 28fire extinguisher, 4 - 5firebrick bottom, 24, 30firing logbook, 28firing safety glasses, 4, 13first firing, 29furniture kits, 16

G

glaze discoloration, 35gold, 31, 35 - 36greenware, 5, 18 - 19, 22, 25, 28 - 30grit cloth, 20grounding wire, 9

H

haik brush, 19

I

insurance, 4

K

kiln furniture, 21, 29kiln wash, 5, 12, 17, 19, 21, 23, 29, 31- 32, 41

L

lid, 20, 22 - 23lid coating, 11lid support, 6LiteLid, 11, 43lusters, 31, 36

M

microwave oven, 5, 34mildew, 25 - 26, 36mirror, 18moisture, 18moth balls, 5

O

ohmmeter, 39Orton Vent Master, 6, 10, 20, 26overglaze, 31

P

peeling glaze, 25peephole, 6, 14, 26peephole plug, 18peephole plug, drilled, 26pinging or plinking sound, 28, 35pinholes, 25 - 26, 35plate holder, 35plates, 31porcelain, 16, 20, 24, 32 - 34, 36posts, 16propane torch, 9, 38Prop-R-Vent, 10, 18, 26, 30 -31, 33putty knife, 19, 21pyrometer, 25pyrometric cones, 4, 11, 19, 22,23, 25

Q

quartz inversion, 25

R

reduction firing, 37respirator, 19 - 20rust, 26, 45

S

sand, 20sand paper, 20shelves, 16, 21shivering, glaze, 28, 35silica sand, 17smoke alarm, 5snap-ring pliers, 7, 39static electricity, 17steam, 18steel base, 11, 45, 46stilt stone, 16stilts, 6, 16, 30 - 33stoneware, 16, 20, 22, 24, 33

T

thermocouple, 17, 21, 23, 29tile holder and setter, 17, 22, 24

U

underglaze, 35

V

vacuuming, 5, 8, 10, 17, 18, 21, 29 -30, 41venting, 6, 25 - 26vitrified, 5, 32, 34voltmeter, 9

W

wall outlet, 5, 29water smoking, 25

2011 South Town East Blvd.Mesquite,Texas 75149-1122Toll Free: 800-876-4328972/288-7557Toll Free Fax: 888-222-6450Fax: [email protected]

paragon ceramic kiln instruction & service manual...2 monitor the kiln during operation!...

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