You can build an airplane out of 1030 mild steel tubing..
You can build an airplane out of wood and fabric...
You can build an airplane out of fiberglass and resin...
You can build an airplane out of plywood...

Go to the EAA site and order a couple of books... Tony BIngelis wrote
a good series... ALex Strojnik also has a great series of books...
REad and understand these two authors and you will be the new Burt
Rutan...

cheers ... denny