Mold Making Guide - One Part Skin Molding
One Part Skin Molding
Producing the Backing Case
The backing case (blue colored in figure) can be made from plaster or epoxy resin or polyurethane, by casting or by polyester lamination. It is often advisable to strengthen the backing case using struts made from cardboard or plywood coated in glass fibre + polyester.
Position the model on the base, attach by screwing, seal the joint between the model and the base with plastiline avoiding any air inclusions. The model is then covered in aluminium foil, with a layer of plastiline of constant thickness.
A mold release agent is applied to all surfaces of the dismantable frame, then the backing case can made from the materials listed above.
The frame is dismantled, the mold is opened. The plastiline is removed together with the protective film, the plastiline is weighed to know how much RTV is to be used.
The pouring and venting holes are made. To pour the RTV drill a hole vertically from the lowest part of the model.
Cover the whole internal surface of the backing case with vaseline to avoid any suction, spread the vaseline by a hair dryer.