I was thinking about making a MC helmet out of metal, but weldable sheet metal is kind-of out of my pricerange right now... plus, to do it right I would want to massage each peice into fitting right, spend hours of grinding to make it smooth, and then have it powder-coated, which... is also out of my price range right now. but yes! Im sure it could be done! My friend has a TON of aluminum lying around from his dad's job, but that would have to bolted or rivited together, as I dont have the neccissary upgrades to my MIG to weld aluminum...