I did the same thing. I started with a 2X4 that was bent on every axis and had twist. I just cut bigger holes in the forms for more adjustment, lined them up and then waited about a week to let the strongback dry out some more (it was delivered in the rain and sat outside all day). I realigned then put on some stabilizer strips that I screwed in. I eyeballed it the other day now that I’m done with it, and it still looks pretty straight. My biggest problem was warped plywood I used for the endforms: The deck ended up skewing slightly to the left side and I didn’t notice until it was too late, so I just built the hull slightly to the right hoping that when I forced them together they would meet halfway in the middle where they’re supposed to be. Turned out ok, but there is a decent sized dookie filled gap where they didn't align 100%. Oh well. Next time I’m going to build a box-beam.

: I buy this one :-)

: Wil try with 2 or 3 layers of 5/8" ply and make sure the rig is properly
: aligned together , and maybe fasten the first 2-3 strips on each side with
: screws to keep it all in place.

: I'm pretty confident this will do the trick.

: Thanks again.

: Jesper