I have been restoring a 1956 Mercedes 300 Sl at the shop.I thought that I had all the metal work done until we stripped the hood and found that it had some old poorly done repairs. There was no saving it .The only solution was to fabricate a new skin. the basic hood shape was fairly easy . The only difficultly was the two 5 foot long hood bubble details.The plan was to make a concrete reinforced fiberglass hammer form to flow form the bubble details into the aluminum skin once the basic blank was formed.Fortunately I have access to another car that I could use for making patterns and a fiberglass buck.The hood was on a finished painted car so we had to be carefull not to scratch or damage it.We taped off all the edges and underside to protect it.We then waxed it with mold release and layer of PVA. water soluble mold release to get a clean release.
We sprayed down some tooling gell coat
Followed with a few layers of cloth and resin
After a bit of water the casting came off clean with no damage to the loaner hood
. More to follow.