: What material did you use for the strongback? I am guessing it
: needs to be solid wood but plywood scarfed together would make a
: really rigid frame but I don't like the idea of driving screw
: into the side of the plywood.

Most are made out of solid wood. I made mine out of two laminations of 1/2" ACX plywood. I overlapped the 8' long pieces by 2 feet. It's really like the gunwales of a SOF and makes a very rigid frame. I use coarse drywall screws to attach forms to the strongback and, yeah, you have to be careful about splitting the plywood. I've built a number of boats on that strongback from 19' strippers to 8' SOF's for my daughters. It's getting tired. For the next one, I'll either use solid wood or maybe edge the plywood with a solid-wood strip to screw the forms to.

=D