Hand cut dovetails have long been a hallmark of craftsmanship. They are a strong and attractive way to join boards together. While not incredibly difficult, getting good results isn't exactly easy. This joint requires a lot of practice and muscle memory to cut accurately. That can be an issue for woodworkers who don't often cut dovetails, or for woodworkers who primarily use power tools for joinery, but occasionally want to add hand cut dovetails to their project.
In this instructable I am going to demonstrate the creation and use of a saw guide. If you want to skip out on making your own, or want a high quaility aluminum one that will last forever, visit David Barron's site
Step 1: Creating the Saw Guide - Tools and Materials
For making a saw guide, you will need the following:
The lengths noted can be adjusted to your needs. I was making several so I used fairly long pieces. You can use shorter lengths, just make sure you have enough room to safely hold the piece while cutting it
1/4" x 1/4" x 14" long hardwood (quartersawn white oak shown)
1/2" thick x 1 3/4" wide x 14" long hardwood (cherry shown)
1/2" thick x 2 1/4" wide x 14" long hardwood (cherry shown)
A small roll of 3/4" UHMW "slick tape" I use this kind
Two (2) 18mm neodymium magnets
CA (super) glue
Finish (oil, shellac, etc)
Compound Miter saw
Sharp 3/4" forstner bit
Using tools is dangerous. Follow all of the manufacturers safety instructions and wear the appropriate personal protective equipment
Step 2: Assemble the Saw Guide
First attach the 1/4" strip to the edge of the 1/2" thick x 1 3/4" wide piece of hardwood using wood glue. I like to add a few drops of CA (super glue) to the wood glue after I spread it. While too brittle of a bond to be used on it's own, CA glue will act as an instant clamp for your wood glue. Hold the piece down with your hands for about a minute, and it won't move. Clamp it up
Next with a jointed hardwood block and 80 grit sandpaper, sand the inside corner. Remove any glue squeeze out and get the surface rough, then plane the outside flush and square
Once that is done repeat the process by spreading glue in the same fashion across the top of both pieces (shown) and clamping the 2 1/4" board over that
Step 3: Cut the Guide
First, decide on an angle. I like the 1:6 (10 degree) angle. It's good for soft and hardwood, and is the best looking (in my opinion) when the pins are very narrow. I made a set up guide for the saw (pictured). Instead of drawing a line 1 inch over 6 inches, I halved it to make it easier - 1/2" over 3". I do not rely on the scale on my miter saw. Once I cut the gulde, I use that to align the blade
The first cut into the guide needs to be with the blade tilted to the left. Then I tilt the saw to the right (using my set up guide to verify the angle) and make another cut. I left about 1.5" at the widest point.
To make the next step easier (drilling for magnets)- make one more cut Tilt the saw back to the left and cut a very thin piece. Since this is the inverse of the guide you cut, you can use it as a jig to keep your guide flat on the drill press table
Step 4: Install the Magnets
I am using 18mm magnets but a 3/4" drill bit because I don't have a 18mm forstner bit. There is a little wiggle room but epoxy has good gap filling properties.
I clamp the guide and the drilling jig I cut in a wood screw clamp and drill it out on the drill press. Go slow and check often. It's critical the magnet be flush with edge. Don't rely on depth stops. Once it's good, flip and repeat.
Epoxy the magnets in being mindful of polarity.
Step 5: Finish the Guide
I am using tru oil, but any finish would be ok. Notice I taped off the inside. I want that to remain as rough as possible.
After finishing I applied the slick tape over the magnets
Why bother with the tape?
Well for one, the magnets are really strong and this stuff is really slick. It reduces friction a lot and wears really well. Another very important reason is to allow for the saw's set. The teeth on a saw are pushed out wider than the plate so it will not bind. If the tape was not proud of the surface, the saw would cut into the guide.
Now lets make some dovetails!
Step 6: Using the Guide to Hand Cut Dovetails
First, get your tools ready. You will need
A dovetail saw. As you can see I have both a Dozuki and a western style saw. Both work well with the guide
Coping or fret saw
Mark your baselines however you like. I like to first mark them a little proud with a pencil, then score that with a knife. Once I have a knife line I use that to set my marking gauge.
Then put the piece in a vise and mark out your tails. Because you are using the guide, you do not need to mark the angles down the face. You just need to mark across the top. I decided on 2 pins for this test piece. Be mindful of the width of the socket and make sure you have a narrow enough chisel
Step 7: Cut the Tails
NOTE: I AM LEFT HANDED
Right handed people will need to start on the opposite side
Start your saw with a very shallow cut straight across on the waste side of your scored line. No angle yet. Now slide your guide up until it clicks against the magnet. Now saw following the angle. You likely will not make it all the way to your baseline. Remove the guide and finish the cut.
Move your guide and cut every other line being mindful of the direction you are sawing in
Now flip the piece in the vise and do the same
Once all the cuts are made, remove the bulk of the waste between the tails with a coping saw. Do not go all the way to the baseline
Step 8: Remove the Waste
For the half pins on the ends, it's best to saw the waste. I reinforce my gauge line with a knife, then remove some material in front of the line with a chisel. This leaves a ledge for the saw to reference. Carefully saw to remove the waste.
Then using a sharp chisel remove the rest of the waste between the tails. Chisel half way, flip, then repeat
A good tip is to "undercut". Chisel straight (90 degrees) for the first bit, then angle the chisel inward a bit and chop to the middle. This helps reduce baseline gaps when assembling the joint
Step 9: Cut the Pins
Transfer your tails to the pin board however you see fit. I am using a dovetail alignment board (future instructable) for this. Use either a very thin lead mechanical pencil or a knife. Knife is preferable.
Use the guide to make the cuts. This time the angled half of the guide will be horizontal and the straight half will run down the board.
Like with the tails, you will need to flip the board in the vise. However with this step the guide will need to be placed on the back side of the piece for one set of cuts. Also remember I am left handed and this will be backward for most people.
Once all your cuts are made, use the coping saw again to remove the waste. Be very careful not to saw into your pins. I like to make sure the "show" face is facing me so if I make a mistake, hopefully it's in the back
Step 10: Remove the Waste
Using chisels, remove the waste back to your baseline. Be careful when chopping. The tails are thicker on one side than the other. I find it easiest to remove the waste from the thinnest portion of the pins, then put it back in the vise to clean out the waste from the corners
Step 11: Finish It Up
Assemble your joint dry before adding glue. It shouldn't take a lot of pressure to mate the surfaces. If it does require a lot of pressure, stop. You run the risk of splitting. Pull the pieces apart and look for burnishing/bruising and pare gently pare away material until it fits well.
Since we marked these a little proud, some clean up is needed. Grab your favorite smoothing plane and clean it up. You are done!
If you are cutting a whole box, you can "gang cut" the tails. Put them in the vise 2 at a time and cut both at once. The guide makes this easy
Just saw lines. Using this guide over and over is a great way to establish the muscle memory to saw straight and true.
Make a few more. Once you get the stock all glued up, it's easy to cut some different angled guides. Just be sure to cut a new drill jig for each different angle. Also a saddle square with a magnet (90 degrees, no angles) is very useful.