Don't buy metal at lowes.
Quick google turned up this :
Metals4u metals distributor - stainless steel, aluminum, brass, pipe sheets, tubing Austin, San Antonio, Dallas TX
Also, call Austin Metal and Iron and see what they can tell you. I buy recycled or surplus materials any chance I get.
Or, use dow corning square edge XPS foam, get it from a distributor of you need to. Do not use polyester resin, it will melt the crap out of it!
Fiberglass supply and resin:
http://www.raka.com/epoxy_kits.html
Epoxy costs, but does not react with your base material.
Click on the warehouse specials link.
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2007 Dodge Ram 3500 SRW 4x4 with 6MT
2003 TDI Beetle
2002 TDI Beetle
currently parked - 1996 Dodge 2500 Cummins Turbodiesel
Custom cab, auto, 3.55 gears