vacuum clamping sides?

Craig Bumgarner

Maldoror wrote:

when you say "balance the grain" do you mean to keep the plies perpendicular, or to have consistent grain throughout, or something else? since you can't do horizontal on the outside ply, how do you arrange the 4 plies?

Yeah, that is a problem. What I do is put the inner two plys at 45 degrees opposed. So if the inner and outer layers are at 0 degrees, the middle two layers are at 45 and -45 degrees. This works well to prevent splitting and keeps the grain stresses balances. If you go 0 - 0 -90 - 0 degrees, the back will concave, in my experience badly and in the wrong direction.

also, finished up all the molds except for the multi-radiased dish.

I've used the dish & go-deck method and still use a 15' radius dish for the back though I don't use a go deck anymore, just clamps. On the top, I prefer to free form it with just the pliage and the braces. That way I can arch my braces however I want them and am not dependent on the dish.

Recently, I've been fitting the braces to the assembled sides before gluing braces to the top. This allows me to get the geometry, especially the bridge height exactly right. This is contrary to how most guitars are built, but it is working for me. I fit the braces to the sides while in their mold. When I am ready to glue the top, I lay the top face down and the sides with braces which are just friction tight in the linings, trace the braces on the top. I take the braces back out of the sides and glue them one at a time to the top using long reach cam clamps. At first I was worried if I could be sufficiently accurate to hit the notches in the linings, but that proved to be no a problem. It helps to use center line marks on the top and braces.