Monday Woodworking 101 - Mitered Dovetail
Dovetails are a strong and attractive way to join corners, however they present a set of challenges. Among one is hiding grooves for bottoms and things like sliding lids. While stopped grooves and lapped (half blind) dovetails present solutions, a mitered dovetail does as well.
I'm not getting too in-depth on the dovetail process. This 101 is mainly focused on the mitered portion. For more in-depth instructions, see my dovetails 101
Also I was a bit pressed for time getting this together and these are far from my best dovetails. However they can still be made presentable after planing them flush.
Starting with a gnarly piece of hard maple, I have a groove cut in one side. Here I am cross cutting it at the bench hook to get my two pieces.
Then I mark the boards for the pins and tails, and mark the baselines like a regular dovetail
I then set my gauge about 1/8" away from the top of the groove and made a mark on the back and end grain of the pin board, and all 3 sides on the tail board. Do not mark the face of the pin board. If so it will need to be planed off
I then lay out the miters with a knife. Starting from the outside corner and ending at the inside of my scribed baseline.
When precision matters, use the right tool. I'm using a Z-saw dozuki to cut the miter, and a small Z-Saw dozuki for the vertical cut
With the piece in the vise I cut the miter staying well off the line. The edge is fragile and a saw will damage it
I go right to the line I scribed
Now I cut inside the vertical line. This cut is important. I want to be right inside my line, and dead vertical. I saw on an angle being careful not to go into the edge or past the baseline. The waste pops out.
This is off the saw. Now ready to clean it up
For this I use a chisel and a guide that is proved at 45 degrees. This was cut on the tablesaw. I label the date on it so it won't just get tossed around with the other scraps
I put the guide I made on top of the piece and against the fence of a bench hook. Make sure the bench hook used has a square fence. I line up the edge of the guide block on the baseline and square against the fence.
I clamp it down with a holdfast. The block tend to creep back a tad so I adjust it with a mallet. Since this is a paring operation, if there is too much to pare away, advance the guide past the baseline and work back
Pare down the edge gently. Making sure the back of the chisel stays tight against the block. Also be sure the surface the piece is on is sacrificial because the chisel will go into it
Paring complete. Nice crisp edge, 45 degrees
Now I flip everything around for the opposite piece and do the same thing
Done. Now for the dovetails
The layout on the tails. Man, this is some ugly maple. The miter is on the left side
this is the tricky part of the layout, and it's only tricky on the tail board. Your "edge" isn't really the edge of the board. It's the end of the miter - the gauge line I struck in an earlier step. I measure in 1/8" from that line. Make sure your narrowest chisel fits to clear the waste
I lay out and cut the dovetail. I used my 10 degree maker. I always cut 14 degree dovetails. As such, these didn't come out that great. Notice in the layout that the line nearest the miter is a straight cut. Horizontal across the end grain and vertical along the face.
With this mitered dovetail, there is only one half pin that is sawn off from the edge.
Laying out the pins. This part is also a bit tricky. Make sure the grooves are on the same side, and are on the inside of the board. I am using a fenced dovetail alignment board here. When doing all 4 corners it is necessary to flip the alignment board in the vise for 2 of the corners
Pins cut. Notice the vertical line near the miter is not cut. This is why I didn't mark it on the face of the pin board
I like to remove the waste with a turning saw.
All chiseled out and ready for fitting and adjustment
This was rushed and it shows as evidenced by the arrant knife line and the gap in the pin at the miter. Also I dropped a piece out of the vise and damaged the fragile miter. However after a slight chamfer to ease the edges, this would be an acceptable joint.
In the next 101 I will outline some tips on fixing issues and gaps in dovetails using this as an example
Here is an example of a mitered dovetail I didn't rush and came out much better. I really like using this joint. A half blind dovetail is easier to cut, but the mitered dovetail allows for the aesthetic off a though dovetail without the hassle of a stopped groove