MIMF

I ruined my IRW back, it cracked next to the center strip. It will be usable for another instrument.
I have an old stop sign.
Is there any precedent for using this material for a guitar back? I see resonator types all metal.
Will hot hide glue stick?
Can one affect a dome shape by beating this stuff with a sand bag into a form?
I'm pulling my hair out.
I hope everyone is well.

I have seen a guitar made from a mailbox, but never one from a stop sign. Why would you put that on the back? It deserves to be up front! But having tried it many years ago, forget about beating it into shape. I don't know what kind of aluminum they use, but it is so hard it is nearly impossible to bend or shape. You will probably be stuck (pun intended) using epoxy to glue metal.

Repair the back you have and use it. We seldom throw away backs just because they have a crack.

If you are wanting to use an aluminum back it should be used with aluminum sides and top also. Brass, nickel, or steel are more common for guitar bodies because they are easier to weld.

Yeah, I'm thinking bigger center strip on the rosewood back and you are good. Joining aluminum to wood requires all sorts of allowances for expansion that I'm not sure I would want to do. But, if you are up for wild'n'wooly, don't let me stop you.

If the crack is not easily repaired (missing wood?) you could remake it as a three piece back - a la D35.
Buying a new back might also be the way to go even if you have to stain the back and sides to make them match.
As to aluminum, I would heed the instructions on the sign.<g>

The old stop sign sounds like the perfect start for the reclaimed materials challenge!!!

I'm surprised Clay didn't recommend formica instead of aluminum.