How do you straighten your form?This is a 64" R/D form 1 piece.
I have used 3/16" and 1/4" thick angle iron but sometimes it takes 1 on each side.
Holding a straight edge to the form there was a gap about 3/16" in the middle.
I needed a 3rd hand, picture did not turn out good.
Sometimes I use 1" x 3/16" flat bar, drill three 1/4" holes, one on each end and one in the middle.
Tighten the outside ones flat to the form, All thread with a nut on the inside and screw it out until flat, 2nd nut to lock it down.
Very little tension on this one, I turned the all thread by hand.