Rough-Arching the Plates

Well, the rib structure is assembled, so now it's time to begin work on the plates. First, I shoot them through the jointer-plane to get a perfect, straight fit. Then I clamp one into the bench, lather it with hide glue, and set the other on top of it. Overnight, the glue will set.

The method is called a "rub joint" because all you do to join them is rub the two surfaces together with the glue on them. There are no clamps involved. It's the sort of thing that'll make you nervous while you're doing it, but I don't have pipe the long pipe clamps we used at the school for joining plates, and this method is surprisingly effective. It says a lot about how perfect the join needs to be, though.



This instrument will have a one-piece back; the maple was already provided for me, and prepping the wood for the back is a story in its own right. I've got this 8 foot board that is plenty wide for the back, and over twice as thick as it needs to be. So I cut off the length that I'll need for it, and now I'm looking at it trying to decide how to thickness it down. So I call up a friend and we decide to rip it in half with a handsaw, so that I can get two backs out of it. After about twenty minutes of trying to cut through it, we decide for a change of tactics and I suggest a chainsaw. So that's what we used. It worked surprisingly well and we just ran the thinner board through the planer a few times, and that's what I used for the back. My only regret is that we didn't have our camera with us to take pictures.





So anyways, the next step is to flatten the underside of the board. Here, I start out with a jointer-plane, then graduate to my block plane.












Getting the top down to thickness was significantly less complicated than the back. I just used my jointer plane on it. Whew. Piece of cake.







It's a little difficult to tell in this picture, but the next thing I did was lay the rib structure on the undersides of the plates and scribe around it. Then, I penciled in another line exactly 3mm away from the outside of the ribs. I also gave the corners a little bit of individual attention to establish the final outlines of the plates. I cut these out with a bandsaw and sanded them a little bit closer to the line.

Then I get to begin the joyful task of rough-arching the back. My last violin was European maple. This is clearly a more local maple like the one I used on my most recent mandolin (and swore vainly that I would never use again). On the mandolin, I had some problems with tear-out. On this particular piece, the problem seems to have been that it was actually not maple at all, but marble. It was one hard piece of wood! I've been keeping a time-log for this instrument so I can tell you in no uncertain terms that the first rough-arch of the back took eight hours.



The first rough-arch of the spruce top, however, only took forty-five minutes.