: I used 2"x3" Rectangle Steel for a strongback and then
: MDF for the "c" shaped spacers, center one gets some
: wedges. I have been happy with it. But I also own a steel
: fabrication company so I also prescribe to use what ever you're
: comfortable with!

My strongback for the past several years has been a simple Yost one, built up of layers of 2x4's bolted together and a 1x6 cap deck screwed to the top. It's not changed shape in the least that I've seen. I still use a stretched string as a baseline just to insure the boats are straight.

I originally used Rob Macks plywood box beam and that worked great, but I screwed up the construction of it and it wouldn't slide apart after it was built. When I moved here I had to sawzall it into pieces to get it out of the shop (that hurt), so had to make a new one. I was at the time making SOF's and the 2x4 one was easy, have built something like 15 boats on it now, including a few in classes that I taught.

Bill H.