: I second the advice to simply make the holes in your forms
: oversized, and use the clearance to align them in spite of your
: strongback's bend or twist. As long as your internal strongback
: is stiff and well supported, it does not matter whether it is
: perfectly straight. Any departure from straight can be dealt
: with by the placement of your forms. You should support your
: strongback rigidly first, in position ready for stripping, then
: align the forms using tight strings as guides.

: Good luck,

: Allan Edie

Me too.

To check the strongback is stable, you could string a line along it, and mark the line. Then leave it for a few days to be sure it is not warping any more. You're going to be checking the alignment of the forms along the beam anyway. And once the first few strips are on (even once just the first strip either side are on), that will stiffen it up a lot.

I had about a one inch warp along the beam, which was fine to work around. (Be aware of it when mounting the end forms though - very easy to mount these pointing off to one side! Note the pencil centreline along the beam, it goes almost to the edge in the middle.

Cheers, Ian