Full-Blind Dovetail

Full-blind Dovetails

P. Michael Henderson

I've done a number of dovetail tutorials but had ignored the full-blind dovetail (also known as the "double lap") primarily because I don't see a lot of use for it. But recently, I decided to do a tutorial on this type of dovetail just for completeness.

I suppose the reason the full-blind dovetail is not used very much is that you can't see the dovetails - and other types of joinery, perhaps made by power tools, are available. And if you did want to do a hidden dovetail, the secret miter dovetail gives, in my opinion, a better looking joint since it looks like a miter joint (no end grain showing).

For this tutorial, I'm going to use two pieces of clear pine about 6 inches wide. Clear pine is straight grained, not very hard and has no knots that might get in the way. I forgot to take a picture of the two pieces of pine before I started the work.

Make sure your wood is flat, square, and the same thickness all around. Also, make sure the two pieces are the same width across. For this tutorial, I'm using two pieces that are the same thickness. You can use pieces of different thickness but your layout will be a bit more complex.

To help you understand where we're going, and what a full-blind dovetail is, I'm going to start by showing the completed joint, and the way the two pieces are cut to fit together. Here's the completed joint.

And here's the two pieces of wood, cut to fit together. Note that one of the pieces has a rabbet cut on the end, while the other does not. In a way, this is similar to the secret miter dovetail which has a rabbet cut on both pieces. One way to think of this full-blind dovetail is as a transition between the half-blind dovetail and the secret miter dovetail.

Here's how the joint fits together.

An immediate question is which piece should be the pins and which the tails? Either way we go, we begin by cutting the piece with the rabbet. I chose to put the pins on that piece because I thought of it as a drawer front - where you wanted to dovetail the drawer sides into the drawer front and didn't want your dovetails to show. And on drawers, you always put the tails on the drawer side.

To get started, there are three dimensions that are needed in making this joint. It's nice to have three marking gauges but you can certainly do with one and just mark each dimension after you set the gauge.

The first I'll set is the distance of the rabbet. I'm going to use 3/16 inch but you could probably get by with 1/8 inch. You don't want it too small or you'll chop through it when chopping out the sockets.

Scribe across the piece that will have the rabbet. In this case, it will be the pins piece.

Then scribe the end of that same piece to mark the depth of the rabbet.

Take your marks around the sides.

Then mark the end of the other piece of wood, the tails piece in this tutorial.

Then set the marking gauge to the thickness of the wood. I'm using three marking gauges but you can do it with one.

Then use that distance to scribe a line on the pin board.

Then set the marking gauge to the depth of the rabbet.

And use that depth to mark the length of the tails.

Now, cut the rabbet. I can set my Kapex saw to only cut to a certain depth and that's what I used to cut the rabbet. You can do the same on your table saw with the miter gauge. I don't cut down to the line because the saw blade doesn't make a nice flat bottom.

I use a chisel to trim to the line. First chop lightly at the back edge of the lip.

The use the chisel to remove the waste to the line. You can register your chisel on the line.

This should give you a nice clean lip.

Now I'll lay out the pins. Make a mark about 3/16 inch from each end.

Then, using a dovetail saddle marker, lay out the pins. Since I'm going to mark the tails from the pins, the exact shape of the pins doesn't really matter much.

After you have the tops of the pins marked, use a double square and a knife and bring the lines down to the scribe line.

This is what it looks like when I'm finished marking.

Saw to the line. Again, the exact shape of the pins doesn't matter that much so if you're off the line don't sweat it. However, when you're sawing, make sure you don't cut into the lip of the rabbet. That will show when the joint is finished.

This is what it looks like after sawing, with the waste marked.

Chop out the waste, just as you would for a half-blind dovetail, taking the sockets down to the lip of the rabbet.

Now to transfer the pins to the tails. To do that, I have to stand the pin board against the tail board. I use a clamp to hold the pieces in place. You can move the pieces into final position by tapping with a soft faced hammer.