What gauge steel? There are tricks to doing it, but they get progressively harder as you go up in thickness. I've heard of people pressing a rod into the metal, with the metal trapped in a frame, but that seems like it would be even more work than just tracking down a shop with a bead roller and begging 10 minutes on it. I got Eastwood's cheapest bead roller off their e-bay store delivered to Mtl for under $150. Beefed it up a little and it handles 18ga easily enough.

You could weld strongbacks to the sheet, but I'd suggest a heavy hit of weld through primer on either side before welding. But that leaves you open to a lot more welding, and distortion.