Machining Through Dovetails

Machining through dovetails using the Leigh or Keller is a piece of cake. The procedure is as follows:

1. Mill your drawer/box pieces square and flat. Size them to the finished dimensions, plus 1/32" or so on the length.
   
   
2. Layout and your workpieces: Left Side Face, Right Side Face, Front Face, Back Face , similar to the method discussed for half-blind dovetails. Mark the bottom of each workpiece. With the Keller, you need to decide which edge (top or bottom) will be your common reference. Keller (and I agree) suggests that you use the bottom edge as your common reference. Thus, your dados for the bottom panel will align. The top edges may not line up perfectly, but this is easily remedied by planing the top edges once the box/drawer is assembled.
   
   
3. Always begin with the tail boards and cut all of the tail boards before cutting your pin boards. The Keller won't require any pin adjustment (you adjusted this when you originally setup the Keller). All Leigh adjustment is done using the pin template.
   
   

   Cutting the Tails

4. Leigh: Clamp a tail board against the edge stop and the finger template. Adjust the desired dovetail layout using the pin template. Once you have the layout set and the fingers tightended down, flip to the tail template.
   
   

   

5. Keller: Clamp a tail board (or clamp two tails together, outside faces facing each other, inside faces facing out) in your vise and clamp the dovetail template to the work piece. I often size my drawer/box to match the spacing of the dovetail template. To determine the exact drawer/box height for half-pins top and bottom, I use multiples of 1-1/8". Then I place the dovetail template over the tail board, so that the edges of the boards are equi-distant from their adjacent template fingers. When all is said and done, I end up with equally-sized half-pins. The Keller Instruction Guide recommends that you mark lines 5/16" to the left and right of the center line of workpiece edge. Then, align the template over the workpiece edge so that a template finger sits within your two lines. Finally, clamp a stop against the "bottom" edge of the work piece.

6. Place your dovetail cutter in the router and adjust its depth to cut the thickness of the pin work piece, plus 1/64". I Scribe a line on the front side of the tail board by butting the "pin" board against the "tail" board, under the tail template and scribing the line using the pin board as the marking edge. Set the router on the template and lower the bit to intersect your scribed depth line. Unlike half-blind dovetail jigs, the depth of cut for through dovetails does not affect the dovetail fit. It only controls how far the tails/pins protrude.
   
   
7. Cut all of your tail boards. On the Keller, you want to keep the bottom edge of all work pieces against your stop. Thus after cutting one end, you will flip the work piece (like a river boat paddle) rather than rotating it (like a propeller). Consequently, for one cut the face will be towards the backing board and will face way from the backing board for the second cut.
   
   

   Cutting the Pins

8. Place the straight cutter in the router and adjust its depth to cut the thickness of the tail work piece, plus 1/64" using the method described for the dovetail cutter above.
   
   
9. Leigh: Place a test pin board in the jig. Rout the test piece and check for fit. Adjust the pin template as necessary. Once it is adjusted correctly, machine all pin boards.
   
   
10. Keller Method 1:
    1. Clamp a pin board in your vise, outside face away from the jig.
    2. Place its mating tail board corner on the end of the pin board in its correct position, relative to the finished product (make sure the bottom edges are aligned) and scribe the first tail socket onto the pin board. Keller suggests that you use a pocket knife. Make sure the blade rides on tail socket edge, not the socket wall.
    3. Place the pin template on the work piece. Line up a finger of the pin template between the scribed lines.
    4. Machine the pin board end.
    5. Repeat all steps for each pin board end.
    
    
    
11. Keller Method 2:
    1. Clamp a pin board in your vise, outside face away from the jig.
    2. Place its mating tail board corner on the end of the pin board in its correct position, relative to the finished product (make sure the bottom edges are aligned) and scribe the first tail socket onto the pin board. Keller suggests that you use a pocket knife. Make sure the blade rides on tail socket edge, not the socket wall.
    3. Place the pin template on the work piece. Line up a finger of the pin template between the scribed lines.
    4. Clamp an edge stop along the bottom edge of the work piece.
    5. Machine the one end of each pin board that shares the bottom edge/face away orientation.
    6. Remove the edge stop. Repeat the scribe and edge stop setup (stop will be on the opposite side) for the pin board ends you have not machined.
    7. Machine the remaining pin board ends.
    
    
    

Using a Leigh Like the Keller

The Leigh demo video tape shows the Leigh setup like a Keller, meaning you can mount the template fingers in a fixed position on a backer board. Consequently, it would have the same benefits of the Keller's ease of use. It's intriguing, but I'm not sure it would work since the tail/pin templates are one and the same!

Using a Leigh Like the Katie

The following is from Lynn Baker:

You have done a great and very comprehensive review on the Keller dovetail jig. Thank you. I would like to pass along an alternate and possibly useful method of using the Keller jig which was demonstrated at a Woodshow in Seattle last year.

Instead of using a vise to hold the work and clamping it to the backer board/template, mount the bit in your router table router, clamp the work to the backer board, and place the template on the router table surface to rout the pins and tails. The router has no tendancy to tip and you have very positive control of the operation. I have used this method exclusively for the past 6 months and have produced noticibly better results than I had before, using the conventional procedure. I hope you find this method useful and thank you again for the fine website.

Lynn Baker Glacier, WA

A Few Suggestions - Notes

• Check out my drawer making tutorial.
  
  
• Reduce tear-out by fronting the work piece with a sacrificial board, using sharp cutters, using a steady feed, taking light cuts, incising the cut where possible, and cutting in a direction that provides as much support as possible for the area being cut. Techniques you need to employ include steadiness, feed speed, and correct direction of cut.
  
  When cutting the pins, I make an incise cut left-to-right (standing behind the jig) across each socket area. Then I enter the socket from the left side and cut all the way back, then across the back towards the right side, and exit towards the front.
  
  
• You can mask tear-out after the project is assembled by smearing glue or epoxy into the tear-out area and sanding the area. The sanding dust will mix with the glue to fill the tear-out. It isn't perfect, but it fixes smaller imperfections.
  
  
• Use a 1-1/2 HP router or greater. The power is needed to keep the cutter speed consistent. The weight actually helps keep the router planted flat on the finger template.
  
  
• Sharp bits reduce tear-out and uneven bottoms. If you use the jig a lot, you will probably want to invest in two sets of bits. That way you'll have one set in the shop while the others are being sharpened. I touch up my bits with a fine and extra-fine ceramic stone. It seems to help.
  
  
• Your work pieces need to be square and flat.
  
  
• Use eye and ear protection. Unlike shaping operations which usually only take a few minutes, machining joints for cabinet drawers and boxes can take hours of continuous router use. Consider purchasing the Leigh RVA (Router Vacuum Adapter) to catch the chips/dust.
  
  
• When making drawers, I use a rip blade to dado the slot for the drawer bottom. A trick I learned from the Frank Klausz tape: After you have finished the last pass for the last drawer side/front, raise the blade and rip the bottom of the back piece. Thus the width of the back piece will be equal to the distance from the drawer side/front top edge to the top edge of the drawer bottom dado. Later, when assembling the drawer, you can slide the bottom in from the back and nail it to the bottom of the back piece.
  
  
• Practice, practice, practice. But practice actually making things (boxes, footstools, drawers), not two workpiece corners like the demo guys. Practice using pine or poplar. Pine teaches you to be careful. Poplar tears out less and is more forgiving.
  
  
• Contact Keller & Co if you have difficulties. From my brief experience, they (David Keller) respond quickly to emails.
  
  

Avoiding Tearout - From David Keller, President of Keller & Co.

The following is an email message I received from David Keller regarding avoiding tearout when machining plywoods and other materials:

Plywoods, and some of the more brittle hardwoods, present a difficulty in router cutting of any kind. Of course, because the dovetail joint requires cutting into the end grain, that portion of the cut is most in jeopardy. Some suggestions for reducing tearout:

1. Make sure that the grain direction of the surface plies is vertical, much as it would have to be if the wood were solid. The cuts into short grain that would occur if the face veneers went across would virtually guarantee tearout and breakage.
   
   
2. When cutting the dovetail sockets, the most vulnerable part of the cut is the short grain above the sloped sides of the cut. To reduce tearout there, keep the rpm of the router high, keep the bits sharp, and make the entry cut with a slower feed rate. This will give the chips a chance to exit without pushing the uncut face veneer out (= blowout).
   
   
3. With drawer, cabinet or box stock, double up the two dovetailed boards, the opposite sides of a drawer, for instance. Make a sandwich of the two boards, cutting them both at the same time, with the exposed faces of the boards on the inside of the sandwich. That way, the boards will back each other up, keeping the face of the wood or plywood absolutely clean. The only face in jeopardy, then, is the entry cut, which is now going to be one of the faces that will be inside the joint when assembled.
   
   
   This not only protects the exposed faces of the wood from tearout, but also cuts setup time in half. For thinner stock, it is possible to cut 3 boards at one time.
   
   
4. When cutting the pins, router technique is essential. Since the boards can only be cut one thickness at a time, the following is very useful:
   
   
   1. Make the entry cut by starting with a light cut across the exposed face, from the left to the right (as standing behind the template, in normal operating position). This is the equivalent of a scoring cut, and neatly cuts the face veneer or surface grain.
      
      
   2. Enter the wood to cut towards the back inside face on the right side of the opening between the template fingers. Go through the wood to the backing block.
      
      
   3. Do NOT circle the router bit around to the left and exit back out to the face. Because of the direction of the router bit rotation, the bit would try to force chips out the front, pushing the face of the wood on the left out in front of the chips - guaranteed to tearout the front edge of the pin.
      
      
   4. Instead, after making the entry cut along the right side of the opening, direct the router bit out to the front via the same path you just used to enter. Slide the router bit out, past the wood, over to the left side of the opening. Then, cut the balance of the waste wood from the face inward. This requires a light climb cut (cutting with the direction of the router bit's rotation), so keep good control of your router in case it might grab and jump. This will finish the cut with an absolute minimum of tearout.
      
      
   5. Thus, you are cutting the pins only from the face inward, for both clearance cuts.
      
      
   6. On some very difficult woods or plywoods, where even these techniques are not enough, place some scrap in front of the cuts to back up the cuts and prevent tearout completely. 1/4" masonite works very well in this role. Make sure the sacrificial board is clamped tightly to the face of the work.
      
      
5. Remember to keep your bits sharp and clean.
   
   

This will ensure a very clean cut for the pins and tails, whether in plywoods or solid wood.

Alternatives and Other Jigs

Don't discount making through dovetail joints by hand or the hybrid method employing both the bandsaw and hand. If you're not doing a ton of through dovetail joints, doing them by hand makes sense. If you're a novice at making through dovetail joints by hand, buy or rent the Dovetail a Drawer video by Frank Klausz. Actually, this video teaches alot more than just dovetails. I found his general woodworking techniques to be very enlightening.

I came up with a chart comparing the Keller, Leigh, AKEDA, and PC Omnijig dovetail jigs. Click here to view it.

Here is a run down of Dovetail jigs you might consider:

• AKEDA DC-16 Through and Half-Blind Dovetail Jig
  The AKEDA DC-16 from AKEDA Jigs Incorporated is the new guy on the block and certainly is a must-consider dovetail jig. Without any adjustments, the jig produced flawless, variably-spaced through dovetails for a box on my first try. I had the same experience with my first drawer. The jig comes through on its promises: no adjustments, excellent dust collection, virtually no setup, dovetail layout is easy and repeatable. It is quite simply a joy to use. Also, I like the geometry of the dovetails. They're more aesthetically pleasing than most machine-produced dovetails. Woodcraft handles the distribution of the AKEDA DC-16 for the U.S.
  
  
• Leigh D4 Through and Half-Blind Dovetail Jig
  The Leigh dovetail jig Leigh Industries, Ltd. Is considered one of the best jigs on the market. I have had one for many years and like it for through dovetails. Leigh offers an extensive array of accessories that allow you to mill mortise and tenons, a variety of box joints, and decorative joints.
  
  
• Porter Cable 16" and 24" (5116 and 7116) Dovetail Jigs
  The Porter Cable #5115 and #7116 jigs run $350 and $400, respectively. They are among the most robust jigs on the market. Porter Cable offers a variety of optional templates to compete with the Leigh as being the most versatile dovetail jig available. Someday we'll get around to publishing a review on it.
  
  
• Porter Cable 12" 4112 Half-Blind Dovetail Jig
  The Porter Cable #4112 dovetail jig runs about $100 and is for my money, the best HB dovetail jig around. Click here to read my PC4112 review.
  
  
• Keller Through Dovetail Jig
  The Keller is considered by some as the easiest-to-use through Dovetail jig. I agree! Models run $150-$450. I purchased my Keller 1601 from Seven Corners Hardware for $189.00, which is considerably less than the show price ($209) or the suggested retail price ($249). Check out the Keller web site! It provides some great info and a gallery of work from Keller users!
  
  
• Woodrat Dovetail/Joinery Jig
  The Woodrat is perhaps the most unique dovetail (joinery) jig on the market, and thus appears to have the largest learning curve. I have not used the jig, but it gets high points for versatility and creative/artistic capacity. Setups appear to be more complex than typical jigs. Runs in the neighborhood of $500.
  
  
• RBI Wood Tools
  RBI sells a PC 4112 look-alike for $100.
  
  
• Hartville Tools Model 12378
  The 12378 is another PC4112 look-alike for $100. Hartville sells aftermarket cam-action clamps for the 12378 that also fit the PC 4112.
  
  
• Woodhaven Dovetail Jigs
  Woodhaven sells a variety of dovetail jigs including their new top-of-the-line jig that can be used in the conventional mode or on top of a router table.
  
  
• Sears Craftsman Dovetail Jigs
  Don't laugh, my father uses one of the cheaper models with excellent results. I recently gave him my old Woodstock Intl jig so he might retire the Craftsman, but don't count on it.
  
  
• Woodstock Intl Half-Blind Dovetail Jig W1099
  This jig, also sold by Harbor Freight (Central Machine) and others, runs between $40 and $60. It works pretty well.
  
  
• Katie Jig
  A relatively new jig that has received good reviews. It runs $250 plus. Marc Sommerfeld demos the Katie at the Woodworking shows. Impressive in that you can clamp a tail and pin board in the jig at one time (given you're cutting them on a router table). This ensures the alignment of the top/bottom edges and could be a real time saver if you had a two router setup like Marc Sommerfeld has at the shows. One drawback I saw in the demo is that the tails/pins top/bottom orientation is swapped on each end, unless you had two setups. If you get a chance to attend the WW Shows, look at the side of Marc Sommerfeld's drawers and you'll see what I mean. Functionally sound, but......
  
  
• Stots Dovetail Template Master
  You use this template master to make dovetail and box joint jig templates. You can use it to make templates of virtually any size. It runs about $50 plus another $30 for the router bits if you don't have them. I want to try this tool, but I just have not had the time to fool around with it. Review coming soon.
  
  
• Incra and Jointech Router Fence Incremental/Positional Jigs
  I would not consider the Incra and Jointech jigs for production work, but they work well if you are up to the setup. They work as advertised, but are time consuming to setup and use compared with dedicated dovetail jigs. For what it's worth, I prefer the Jointech positioner over the Incra. The Jointech is more roubust, uses leadscrew technology instead of the incremental racks, templates are easier to use, provides built-in centering, and their fence construction and design is excellent.
  
  
• The $19.99 Half-Blind Dovetail Jig
  The Popular Woodworking September 1999 issue ran an article on a $19.99 half-blind dovetail jig. Click here to view the article in PDF Format. The author (Troy Sexton) explains how to make a simple router template to machine the pins. The tails are cut on the bandsaw. The price of "$19.99" includes $11 for a 23/32" diameter template guide and $8.95 for 1/2" 14 degree a dovetail bit. You probably already have these items. The simplified process:
  1. Rip a 5/16" thick template the same width as your drawer pieces.
     
     
  2. Use a dado to cut notches on one end of the template. One notch per tail.
     
     
  3. Clamp the template to the back side of the drawer front.
     
     
  4. With your router sitting on top of the template, run the router in and out of the notches.
     
     
  5. Use the cut pins to layout the tails.
     
     
  6. Cut the tails on your bandsaw.

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