I made a small curbside find today, a 3" stack of sheet steel pieces with a "FREE" sign taped to them. So into the truck they went. The pieces are 6-10" wide by 30-36" long and range in thickness from 1/16" to 1/4". Unfortunately, most of the thicker stuff is a bit curved, bowed the long way anything from 1/2" to 1" at the center. I'd guess from stress caused by shearing them to size.
Any suggestions how to flatten them out?
Tove