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Installers andInspectors Guide

for CADWELD®

ElectricalConnections

E1975LT08NAEN:E1975LT08NAEN 11/11/08 4:24 PM

This handbook is designed to guide theperson in the field in the installation andinspection of CADWELD® exothermicwelds, including CADWELD® EXOLONand CADWELD® ONE SHOT styles.

The parameters and criteria outlinedin this manual are based on testsperformed by ERICO®, and on ouryears of experience using CADWELDmaterials in the field to developexothermic technology.

If you have any questions about thematerials and methods used in theCADWELD process, contact your localCADWELD representative or ERICO atwww.erico.com


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The CADWELD® Process......................2

The CADWELDConnection..........................................3

It’s Easy to MakeCADWELD Connections......................4

CADWELD QualityStandards............................................6

Specifications forCADWELD

Connections........................................6

CADWELD MoldInspection............................................7

Inspection of CADWELD ConnectionsGeneral Indicators..........................8Size...............................................8Color...........................................10Surface Finish.............................10Porosity.......................................10

Visual Inspection...........................11Photographic Guides....................12Field Situation Guide....................17

CADWELD® ONE SHOT ConnectionsGeneralIndicators..............................21Field Situation Guide forCADWELD ONE SHOT

Applications......................................22

Contents


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The CADWELD® Process

The CADWELD® process is a method of makingelectrical connections of copper to copper orcopper to steel in which no outside source ofheat or power is required.

In this process, granular metals (granularcopper oxide and aluminum) are dumpedfrom a container into a graphite crucibleand ignited.

The reduction of the copper oxide by thealuminum (exothermic reaction) producesmolten copper and aluminum oxide slag. Theslag floats to the surface and the disk melts,allowing molten copper to flow into the weldcavity and complete the weld. The weld isallowed to solidify. The mold is removed andmade ready for the next weld. The processtakes seconds to complete.

BEFORE WELDING: READ, UNDERSTANDAND FOLLOW ALL SAFETY INSTRUCTIONSPACKAGED WITH YOUR MOLD!

Mold

StartingMaterial

CADWELDWeld Material

Tap Hole

WeldCavity

Ground Rod

Cable

Steel Disk

Crucible

Cover


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A CADWELD welded connection produces ajoint (or connection) superior in performanceto any known mechanical or pressure typesurface-to-surface contact connector. By virtueof its molecular bond, a CADWELD weldedconnection will not loosen or increase inresistance over the lifetime of the installation.

CADWELD Welded ConnectionsOffer the Following Advantages:• Current carrying (fusing) capacity equalto that of the conductor.

• Will not deteriorate with age.• Permanent molecular bond that cannotloosen or corrode.

• Will withstand repeated faults.• Low labor costs.• Made with inexpensive, lightweightequipment – saves time on the job site.

• No special skills are required.• No external power or heat required.• Can be checked for quality by visual inspection.• Portable system.

The CADWELD® Connection

The CADWELD® process is applicable tomaterials other than copper. Some of thesematerials are:Common steel Wrought iron BronzeChromax* Stainless steel CommerciallyEverdur ® Cor-Ten® pure ironSteel rail Monel Silicon bronzeCopper-clad steel Cast iron Nichrome*Columbium Kama* Nichrome V*Niobium GalvanizedBrass and bethanized

steel*Resistance Heater Materials

CADWELD metal

Cable sleeved byCADWELD metalbeyond weld formechanicalstrength

Molecular bond ofcable strand endsto CADWELD metal


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It’s Easy to Make CADWELD®

Connections

Detailed instructions and safety precautionsare provided with every CADWELD® mold.You must read and understand allinstructions before making a connection.

1.• Dry the mold and the conductors.• Clean the conductors.• Place cable ends in the mold.

2.• Close the handles to lock the mold.• Drop the metal disk into the mold.


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3.• Dump the weld material into the mold.• Sprinkle the starting material over the weldmaterial and onto the lip of the mold.

4.• Close the cover and ignite.• Open the mold after the metal solidifies.• Remove slag from mold before next connection.

5.• A completed CADWELD® connection.


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CADWELD® Quality Standards

Specifications forCADWELD® Connections

All CADWELD® materials are produced tohigh standards under stringent qualitycontrol. All CADWELD connections aredesigned and tested using CADWELDmolds, weld metals, and accessories.

In the absence of any standards, national orinternational, we cannot accurately predictthe individual product standards of ourcompetition, either known or unknown.Therefore, mixing of one manufacturer’smolds with another manufacturer’s weldmetal can predictably lead to finished weldsthat do not meet the standards of eithermanufacturer. After all, one of the advantagesof exothermic welding as a welding processis the fact that it is pre-engineered.

All grounding system connections shall bemade by the CADWELD process. Connectionsshall include, but not be limited to, all cableto cable splices, T’s, X’s, etc.; all cable toground rods, ground rod splices, cable to steeland cast iron; and cable lug terminations.

Procedures listed in all CADWELD instructionsshall be followed. Molds shall not be alteredin the field.

All materials used (molds, weld material,tools, accessories, etc.) shall be CADWELDmaterials, manufactured by ERICO®. Materialsof different manufacturers shall not bemixed.


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A CADWELD® mold is designed to last foran average of 50 connections. This will varyaccording to the care given the moldduring use.

Inspect the mold regularly. Check thefollowing items to determine if a moldshould be replaced:Cable Opening• The conductor should fit snugly.A loose fit will cause leakage.

• The opening should not be chippedor worn.

Weld Cavity• The cavity should be well defined.• There should be no chips or gouges.

Tap Hole• The tap hole should be well defined.

Disk Seat• The seat should not be worn or chipped;the disk must seat properly.

Mold Parting Face• The parting face should not be chipped.• The parting face should always becleaned properly. Use a clean shop towelor newspaper and wipe clean. Using awire brush to clean the mold will causeerosion and quickly destroy the mold.

CADWELD® Mold Inspection

Mold partingface smoth

Tap holewell defined

Weld cavitywell defined

Chip in moldparting face

Disk seatworn

Mold partingface haserosion lines

Chip inweld cavity

Cableopeningworn

Good Replace


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Proper inspection of a CADWELD® connectionrelies on the judgment of the field personnel.Look closely at the size, color, surface finish,and porosity of the connection.

Following the guidelines below will assist inmaking meaningful inspections. Photographsof good, acceptable, and reject connectionsappear on pages 12-16.

Size1. No portion of the conductor within theconfines of the weld should be exposed.

2. Maximum depression under the riser onhorizontal connections (after the slag hasbeen removed) should be no lower thanthe top of the conductor.

A low fill indicates:(a) Not enough weld material was used.(b) Excessive leakage of molten metal.(c) Improper positioning of the

conductor inside the mold.(d) Movement of conductor.

3. Excessively high fill (tall riser) indicates:(a) Too large weld material size was

used (connection is still acceptable).(b) Apparent volume increase due to

contaminants in conductor or mold(see “Porosity” on page 10).

Inspection of CADWELD®

ConnectionsGeneral Indicators


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Unacceptable

Type VS

Type GT

Type SS

Higher than normal

Normal

Minimum acceptable

Higher than normalNormal

Minimum acceptable

Higher than normal

Normal

Minimum acceptable

Strands showing(below weld level)


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ConnectionsGeneral Indicators (continued)

ColorThe color of a CADWELD® connection is bestseen after a light wire brushing of theconnection. It should normally be gold tobronze in color. Occasionally, it may be silveryat the top. This silver color indicates “tinsweat” of the surface, a normal condition.A CADWELD connection to cast iron orgalvanized surfaces is often silvery due toalloying with the metals.

Surface FinishThe surface of a CADWELD connectionshould be reasonably smooth and free ofmajor slag deposits. If slag deposits cover morethan 20% of the connection surface, or if anycable strands are exposed after slag has beenremoved, the connection must be rejected.

PorosityThe connection should be essentially freefrom porosity. Excessive porosity is normallythe result of contaminants (water, oil, dirt, etc.)in the conductor and/or mold. A few smallpinholes may be present on the surface ofthe riser. The depth of a pinhole must neverextend beyond the center of the conductor.To check the depth, probe the pinhole witha 1/32-in.-diameter wire (paper clip). Rejectthe connection if the depth of the pinholeextends beyond the center of the conductor.


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Photographic GuidesLike all electrical connections, a visualinspection is no guarantee of performance.Crimped or bolted connections cannot beinspected visually, but CADWELD®

connections can be visually inspectedand provide an indication of the qualityof the weld. Visual inspection isrecommended as a practical minimum.

Use the photographs on the following pagesas a guide to visual inspection. CADWELDconnections are normally rated as good,acceptable or reject.

A good connection is a normal weld withonly minor surface imperfections.

An acceptable connection is a less thannormal weld, but a good performing weld.Imperfections indicate that 1) a new moldis required, 2) a change in procedure isnecessary, or 3) the proper mold conductorand/or weld metal should be used.

A reject connection shows inadequate fill oran extra high riser due to 1) use of incorrectprocedure, 2) use of incorrect equipmentand/or equipment worn beyond its usefullife, or 3) use of incorrect material.


ConnectionsVisual Inspection


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Good.A solid weld with only minor surfaceimperfections.


ConnectionsPhotographic Guides

Acceptable.Fill is lower than normal, but still sufficient.


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Acceptable.A worn or incorrect mold was used,allowing leakage around conductor. The fillin this connection is sufficient to allow it asacceptable. Attention to mold is requiredprior to making next connection.

Acceptable.The presence of water/moisture inconductor strands or mold indicates thatone or both were not properly dried.Although the riser is porous, the weld issolid. The degree of porosity is not sufficientto reject this connection.


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ConnectionsPhotographic Guides (continued)

Reject.Extreme amounts of slag on surface arecaused by weld material leaking past disk orcomplete lack of disk. Inspect the conditionof mold disk seat and check disk positioningprior to making the next connection.

Reject.Excessive water in cable strands and/or mold.Cable and mold must be dried by heating.


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Reject.Light carbon traces on cable and connectionare evidence of oil on cable strands. Oilycables must be cleaned with safety solvent.

Reject.Heavy carbon coating on cable andconnection is evidence of large amountsof oil or grease on cable. Cable must becleaned with safety solvent.


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ConnectionsPhotographic Guides (continued)

Reject.Fill too low. Weld cavity was not filled overcable strands. “Fins” indicate that the moldwas not closed tightly due to incorrect mold,incorrectly adjusted handle clamp, orpresence of foreign material in mold partingline. Before making the next connection,check the mold for each of the above.

Reject.Fill too low. Weld cavity was not filled overcable strands. Absence of leakage indicatesthat weld material size was incorrect (toosmall) or thru conductor moved.


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Field Situation Guide

Most field difficulties can be overcome bychecking the following problems.

Problem ATHE MOLD DOESN’T CLOSE TIGHTLYCheck for:1. Adjustment of handle clamps.2. Cables out of round or bent.3. Dirt or slag in mold parting line.4. Correct cable size.

NOTE: Use “C” clamp if necessary.

Problem BTHE CONNECTION IS COVERED WITHEXCESSIVE SLAGCheck for:1. Weld material leaking past the disk, caused by:(a) Chipped graphite at tap hole.(b) Disk moved when weld material was dumped.(c) Disk not properly seated.(d) Disk was not installed.

NOTE: A small amount of slag on the surface is notabnormal.

Problem CMOLTEN METAL “SPITS” OUT OF THECRUCIBLE WHEN MAKING A CONNECTIONRemedy:1. See Problem D

Problem DTHE CONNECTION IS POROUSCheck for:1. Presence of moisture either in conductoror mold.


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Field Situation Guide (continued)

Remedy:(a) Dry the conductor by wiping and heating.(b) Heat mold with torch (to above 212°F) or

by igniting weld material in mold withoutany conductors, taking care to preventburns from the hot meterial running outof the mold.

NOTE: Do not use the second method of heating if themold has wear plates.

Check for:2.Other contaminants (oil, insulation, etc.)present in conductors.Remedy:(a) Use a safety solvent to wash the conductor,

then dry it.(b) If insulation is present between strands,

remove it.Check for:3. Mold packing material in weld cavity ofmold.Remedy:(a) Always apply mold packing material to

conductor after mold is closed.

Problem ETHE CONDUCTORS DO NOT WELDCheck for:1. Conductors were not properly cleanedand dried.Remedy:(a) Remove oxides with a wire brush. If heavily

oxidized, have fresh-cut conductor end anduse CADWELD® Heavy Duty molds.

(b) Dry conductors with a torch.

Check for:2. Conductors not properly positioned inthe mold.Remedy:(a) Check for proper gap or butting as required

(see the mold tag and read the instructionspackaged with mold).

(b) Check to be sure gap is centered under taphole.

NOTE: In some cases, the run (thru) conductor must becut and gapped. Follow instructions for same or useCADWELD Heavy Duty molds.


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Problem FTHE WELD MATERIAL LEAKS AROUNDTHE CONDUCTORRemedy:1. Use packing material around the conductorafter the mold is closed.

2. Use molds with wear plates (which alsoact as chill plates).

3. Check for the proper mold. Mold must besized for the cable being welded.

4. If the mold is excessively worn, replacewith a new mold.

Problem GTHE CONNECTION HAS “FINS”– METAL IS LOSTCheck for:1. Mold not completely closed.2. Mold worn beyond useful life and needsreplacement.

Problem HTHE CABLES PULL OUT OF THE MOLD DURINGWELDINGRemedy:1. Use a clamp (CADWELD® B-265) or othermeans to prevent movement of conductorswhen welding.

Problem IINSUFFICIENT FILL MATERIAL TO COVERCONDUCTORSCheck for:1. Use of proper weld material size

(see mold tag).2. Too large a gap between conductors(see positioning instructions).

3. Mold leakage.Remedy:

(a) See Problem F.(b) See Problem G.(c) See Problem H.

4. Conductor movement.Problem JTHE RISER IS TOO HIGHCheck for:1. Use of proper weld material

size (see mold tag).2. Moisture in mold or conductor.Remedy:

(a) See Problem D.


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Field Situation Guide (continued)

Problem KTHE MOLD WEARS OUT QUICKLY(Molds should produce an average of 50connections.)Remedy:1.Use CADWELD® B-265 cable clamp forhard-drawn copper or DSA Copperweld®.

2.Clean the mold with a soft brush, cleancloth, or newspaper. DO NOT USE A WIREBRUSH.

3.Use care in removing the mold from afinished connection to prevent chipping ofmold.

Problem LWHEN WELDING TO STEEL, THE WELD DOESNOT “STICK” TO THE STEELRemedy:1.Clean the steel with a rasp or grinder tobright metal. When grinding, use anERICO® approved grinding wheel only.All mill scale, paint, and/or other coatingmust be removed. Wire brushing will NOTsuffice. Grease must be removed withsafety solvent before cleaning.

2.Clean galvanized surfaces with a wirebrush or emery cloth. However, extraheavy galvanized steel must be cleanedwith a rasp.

3. If the steel is moist, heat with a torch(from the back side if possible). Any carbondeposit from the flame must be removed.

4.If conductors are not in proper position,check the instruction sheet.

Problem MWHEN WELDING TO DUCTILE IRON OR CASTIRON, THE WELD DOES NOT “STICK” TO THESURFACERemedy:1.Remove all coatings before cleaning.2.Clean the surface with a rasp orgrinder to bright metal. When grinding,use an ERICO-approved wheel only.


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CADWELD® ONE SHOT connections do notalways follow the same rules as connectionsmade with graphite molds.

CADWELD® ONE SHOTConnections

3. Clean the surface with a safety solventafter grinding or rasping.

4. Use CADWELD® XF-19 alloy weld material(orange cap).

1. No portion of the cable within theconfines of the sleeve should be exposed.

2. Maximum depression under the riser(after the slag has been removed) shouldbe no lower than the bottom of the cable.Lower fill indicates excessive leakage ofmolten metal or improper positioning ofthe CADWELD ONE SHOT mold.

Higherthannormal

Normal

Minimumacceptable


Field Situation Guidefor CADWELD® ONE SHOTApplications

Below are typical field situations relatedto CADWELD® ONE SHOT connections.

Problem AWELD DOES NOT “STICK” TO GROUND RODRemedy:1. Ground rod must be cleaned with a rasp

to bright metal. All scale and/or othercoating must be removed. Wire brushingwill not suffice. Grease must be removedwith a safety solvent before cleaning.

2. If conductors are moist, heat with a torch.Any carbon deposit from the flame mustbe removed.

Problem BPOROUS CONNECTIONSRemedy:1. Dry the conductors by heating with a

torch.

Problem CDISCOLORED, BLACKENED CONNECTIONSRemedy:1. Remove insulation and clean oil from

conductor with a safety solvent. Then,dry surfaces before welding.

Problem DWELD METAL LEAKSRemedy:1. CADWELD ONE SHOT mold is wrong size.

See catalog.

Problem EINSUFFICIENT FILL METALRemedy:1. Conductor not properly positioned in

CADWELD ONE SHOT mold.

A7D E1975LT08NAEN 0117.5M8

PH: 800-248-9353FAX: 800-677-8131www.erico.com

Copperweld is a registered trademark of Copperweld Steel Company, Fayetteville, TN.Cor-Ten is a registered trademark of United States Steel Corp.Everdur is a registered trademark of Anaconda Copper Co.

Copyright ©2005 ERICO International Corporation. All rights reserved.CADDY, CADWELD, CRITEC, ERICO, ERITECH, ERIFLEX, and LENTON areregistered trademarks of ERICO International Corporation.


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