04-20-2009, 03:19 AM
Depending on what I am casting, I make molds either out of RTV Latex (room temperature vulcanizing) or a two-part acrylic casting mixture. With the RTV, I cast the sections of stone wall out of Hydrocal. The acrylic molds is make using the LEGO trechnique and then use them to cast resin parts. For smaller molds, I just use a plastic parts drawer from one of those multi-drawer small parts cabinets, set the part face up and slowly flood the drawer with RTV compound until the detailed face of the positive master is well covered. This works well for walls, flat panels and such where the detail is essentially on one face and the sides and top. After it dries thoroughly I remove the mold, flex, peel and remove the molded copy. I then return the mold to the drawer to keep it flat and refill it, or leave it stored flat until the next time. Casting is a useful technique for mass producing some items that you will need a lot of. I found a site belonging to a guy who casts freight car bodies, something I'm working my way up to, long with two-part indexed molds. Much to learn. :?