Re: Tinsmith's in frame gas tank for cantilever Schwinn.
Cool project - keep the photos coming and those whiskers out of the rollers!
I've done some hammer forming over wooden bucks in steel and it really is amazing how far you can stretch the metal and how tight you can make the corners. Yep, you need to keep the buck slightly smaller than the finished piece to allow for metal thickness and space for inside corners. Copper should be even easier.
Looking forward to seeing your project come together.