December 2000 Popular Woodworking - ?· POPULAR WOODWORKING December 2000 Start With a Sandwich Begin…

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TRANSCRIPT 47Years ago when I first learnedto cut dovetails, my firstjoints werent things ofbeauty. Sometimes there weremore shims than pins. Over time,my work got better and faster.But despite the improvement inmy skills, I still had trouble cut-ting tails or pins consistently, es-pecially if I got out of practice.This jig allows you to make great dovetailson your first day. The idea came to me whenI was building a Shaker stepstool using hand-cut dovetails. I made a jig that fit over the endof a board to guide my saw through the cut andprovide a perfect tail. The jig didnt cut pinsand only worked on 34"-thick boards. I guessI wasnt thinking big that day.A few weeks later it came to me: Why notbuild a jig that cuts both tails and pins and isadjustable to a variety of thicknesses? So Imade this jig. From the first joint I cut usingit, I got airtight joints. It was very cool.This jig uses a 9-degree cutting angle.Woodworking books say that 9 degrees is in-tended more for soft woods than hardwoods(which use a 7-degree angle) but I thoughtit a good compromise. You can build this jigentirely by hand, but I cheated and used a tablesaw for a couple of the precise angle cuts.Let your conscience be your guide.One of this jigs peculiarities is that youllsometimes have to cut right on the pencil line.As designed, this jig works best with Japanese-style Ryoba saws on material from 38" to 34"thick. Use the saws ripping teeth when mak-ing your cuts. You could modify this jig to ac-commodate Western saws, but youd have totake a lot of the set out of the teeth so you did-nt tear up the faces of the jig. The set of a sawsteeth basically allow you to steer a bladethrough a cut. This jig does all the steering.You just have to press the gas. PWSave yourself yearsof practice with thisincredible jig that helpsyou hand-cut perfectthrough-dovetails. ailJIGailJIGBy Jim StuardPhotos by Al ParrishPOPULAR WOODWORKING December 2000Start With a SandwichBegin by sandwiching threepieces of wood.This part is madefrom two pieces of 34" x 6" x 36" ply-wood with a piece of 1" x 1" x 36" solidwood centered between.Use a spacer toindex the center precisely in the middle ofthe larger panels. Glue and nail the sand-wich together.Cutting the Angles Set your saws blade to 9 degrees andcrosscut the end of the sandwich while itsflat on the saw.Next, tilt the blade back tosquare and set the miter gauge to 9 degreesas shown (above).You can use the angledend of the sandwich to set your miter gauge.Lay out a center line down the middle of thesandwich and mark from the end of the lineabout 312". Use a sliding t-bevel to transferthe angle to the flat side.This yields a jig thatwill let you cut dovetails in material asnarrow as 3" wide. Any narrower and youllhave to shorten the jig. Lay the extrusion flaton the saw table and cut to the line.The jigwill be a little narrower on the other side butthats OK.Remove the Waste Attach the 12" x 414" x 6" faces to theends of the jig with nails and glue.Use aRyoba saw to start the cuts to open up thechannels in the jig (above and right).Use a coping saw to cut out the part ofthe ends that cover the little channels in thesandwich (far right). Note the blade is perpen-dicular to prevent binding on the jig itself. Cleanup with a rasp and sandpaper.Add an AbrasiveUsing contact cement, attach 120-grit sandpa-per to the same side of the inside channel, onboth sides of the jig.Quick ClampingDoctor up a couple of 14"-#20 T-nuts by pound-ing over the set tines and grinding off a little ofthe threaded barrels.With some two-part epoxy,attach some 18"-thick wooden pads to the faceof the T-nuts.When the epoxy is set, sand thepads to fit the T-nuts. Run your thumbscrewsthrough the threaded inserts and attach the T-nut/pads to the thumbscrews with some thread-locking compound (available at any automotiveparts store).Finish the jig by attaching somethingslick to the faces. I used some UHMW (UltraHigh Molecular Weight) plastic self-stick sheet-ing. Its 116" thick, and if you wear out the mater-ial on a face, you just peel off the old materialand stick on some new.You could just as easilyuse some wax on the wood faces.Youll just haveto sand them flat, eventually.Cutting Tails and PinsUsing the jig couldnt be simpler. I cut tails first.Thats a personal choice, but this jig will workwell whether youre cutting tails or pins first.Thelayout is a little simpler than when going free-hand. All you do is mark the depth of the cutwith a marking/cutting gauge and lay out thespacing for the tails on the end of the board.Usethe pencil marks to cut out the tails (above)and when you get the waste cleaned out, use thetail end of the board to lay out the pins (right).Use a sharp pencil for marking, then cut out thepins. Check the fit of the pins to the tails using apiece of scrap as a hammer block across thewhole joint. If theyre a little big, do some fittingwith a four-in-hand rasp.The joint should besnug, but not so tight that it cracks the tail boardwhen hammering the joint together.12347 8 9www.popwood.comThreaded InsertsLay out and drill 516" holes as shown in thediagram.These accommodate the threadedinserts for the set screws. Attach the threadedinserts using a hex key/Allen wrench.2"9 forpins1/2"2 1/8"1"2 1/8"6"CLFind centerline fromthe narrow side of the jigModified"T"-nutWoodenpadThreadedinsert5/16"holeThumbscrews1/2" x 6" stock3/4" x 6" stock1" x 1"stock9fortailsMeasure 3 1/2" across centerof wide side for cross-cutting jigfrom sandwichApply sandpaperto inside of wide side of jig9090Schedule of Materials: Dovetail Jig No. Item Dimensions T W L Material2 Sides 34" x 6" x 36" Plywood1 Center block 1" x 1" x 36" Poplar2 Faces 12" x 414" x 6" PlywoodSuppliesLee Valley800-871-81582 14"-20 flanged insert nuts #00N10.13,$.09 each.Ried Supply800-253-04212 14"-20 thumbscrews #MIT88,$1.99 each.Woodcraft800-225-11533"-wide UHMW self-stick tape#16L65,$17.99/roll5 610