I have patterns made to do the interior wrap/seat for the FED I'm building and wondered what material to use. My plan is that the wrap will be on the inside of the roll cage/chassis structure and will extend to a vertical tube just behind the rearend housing and will also be used as the seat. I have 2 - 2" X 1/8" steel straps welded to the cage which are curved to form the seat bottom, and will be either riveted (maybe solid driven rivets), or welded to the wrap to make it one piece. My patterns are Left and Right and will be butted and spliced together with a strip again riveted or welded together in the center behind the driver's spline. I would put the splice strip to the outside, so the inside would be smooth. I plan to install it using Dzus button head fasteners. FWIW, the outer body panels (outside the chassis tubes) would extend slightly past the forward edge of the interior so they would actually have an overlap.
All that being said, I have three types of material in my shop to do the wrap and the seat bottom and wonder if any of them would be an appropriate or acceptable material....18 Ga. mild steel, .040" aluminum and .063" aluminum. I believe the aluminum sheets are 5052 alloy.
I would appreciate some input from experience and say "Thank You" in advance. There's probably a spec somewhere in some rules, but I haven't dug around the internet for it yet.
Thanks
Lynn