All week I’ve been itching to saw these joints that connect the legs to the benchtop. I’ve never cut a 5″-deep dovetail joint in a 6×6, so I wasn’t sure what to expect.
It was easy going until my enormous saw suddenly stopped cutting. Had the flesh-detecting technology in my tenon saw kicked in? (Ye Olde Saw Astyntan?) But I’m getting ahead of myself here.
Let’s back up to Tuesday when I was laying out these joints. I spent a long time staring at the original plate from Roubo’s “L’Art du Menuisier,” and it wasn’t making sense to me. Robert Lang and I tried sketching the joint (electronically and on paper) to reconcile the odd perspective of the joint (I believe it’s supposed to be in parallel projection instead of in perspective, but even that doesn’t really explain it).
Oh, and there was the fact that the original text’s dimensions don’t really jibe with the drawings.
So I set forth to create a joint that resembled the drawings of workbenches shown throughout the four volumes of Roubo , and that obeyed some of the basic rules of wood-to-wood joinery set down by Joesph Moxon. And it would split my top like a muffin.
The first question was proportioning the thickness of the sliding dovetail and the tenon. These legs are finishing out a little bigger than 5″ x 5″. So I went for a 1-1/2″-thick dovetail, a 1-1/2″ thick tenon and 1-1/2″ space between the two. The remainder (a bit more than 1/2″) was the shoulder at the back.
About that angle on the dovetail. It looks a lot steeper than is typical in a drawer or carcase. Roy Underhill suggested in “The Woodwright’s Shop” to use a dovetail that has a slope of 2-1/2″ to 1″ when he built his bench with a rising dovetail.
That sloped looked too shallow. After fussing around, we settled on a slope that was 1-3/4″ to 1″. That is one steep slope (about 30Ã?Â°), but it looks right. So be it.
I laid out the joints last night before I left work and started in on the sawing this morning with a honking enormous 11-point tenon saw that’s 16″ long.
I needed a bigger saw. I couldn’t reach the baseline because the brass back hit the top of the leg. That was a new sensation.
So I got out my full-size ripsaw. And that’s when the fun began. Even with the big saw, it took some time to rip those cheeks. I could have written a couple blog entries while sawing one joint. But it’s going well.
Soon I’ll get to make the female part of the joint and give my mortise chisel and brace a workout.
– Christopher Schwarz