Mold making and casting using todays modern materials allows small businesses, hobbyists and small scale manufactures to do limited runs manufacturing their own products without the expense on and complication of injection molding or other expensive processes. Flexible silicone rubber molds are used for reproducing artwork, prototypes, sculptures, dolls, figurines, or other 3 dimensional items. Flexible RTV (room temperature vulcanizing) molds can take incredible detail from the original model. RTV molds are great for limited production of various cast pieces (artwork, puppets, props, prototypes, etc.)

    There are other flexible mold materials, such as latex rubber, urethane rubber, and polysulfide rubber. Each has its own advantages and disadvantages. Flexible RTV silicone molds are higher in cost, but in terms of ease of use, mold longevity and the range of casting materials that can be cast in them, this is where silicone molds will typically outshine the other types of mold rubber.

    A variety of casting materials can be cast in flexible RTV molds, and one of the most popular casting resins used these days are fast cast urethane resins. Other materials that can be cast are polyester resin (or traditional fiber glass), epoxy resin (or epoxy-glass), wax, concrete, plaster or other gypsum casting materials (Hydrocal, Hydrostone, Ultracal, etc.).

    Latex, urethane, and polysulfide rubber molds can also be used with some of these materials, but you really need to know if the casting material and a given mold material are compatible. Otherwise the mold could be ruined or deteriorate rather quickly.

    There are different processes or casting techniques used depending on the casting material and/or the item being cast. Solid poured castings, slush casting or rotocasting for hollow cast items, and hand layed up fiber glass (polyester or epoxy), pressure casting, and core molding (another method for making hollow castings) are some common casting techniques used in flexible rubber molds.

    The process used can depend on what the end product is, which in turn can affect how the mold needs to be constructed. So early on one needs to decide on the casting material and process that will be used, so the proper mold can be made. Some types of molds can be used for more than one process.

    If you have a mold making or casting project you would like us to consider, please contact us.