Flexible mold

A mold is a hollow shape which exactly encloses the shape of a desired object. The object is usually created by pouring a liquid into the mold and allowing it to solidify: typical liquids include molten metal or plastic, plaster of Paris, epoxy resin.

Molds generally divide into two classes: solid or flexible.

There are five different types of flexible mold compounds in significant use today.

Hot-Melt

polyvinyl chloride

Latex

Silicone rubbers

Polysulfide rubbers

Polyurethane flexible mold compounds

From the standpoint of general utility and economy, the polyurethanes surpass all other types.

Equipment and accessories

Mixing containers and stirring paddles should be of metal or plastic and always spotlessly clean, warm and dry. Use 1-inch fiber brushes cut down to 1-inch length for application of wax release agent. A regular short fiber scrubbing brush should be used for buffing wax from deep grain or fine design of model or pattern.

Sulphur Free Plastalina Clay (The Compleat Sculptor, New York City) is excellent for modeling, laying up and sealing models and dams. 1/4"-3/8" plywood should be used for mounting models. Scrap pieces can be sawed to rectangular shapes and used for straight side retaining dams.

Lightweight sheet metal, linoleum and heavy cardboard can be used for circular or irregular shaped retaining walls. Sash cord and masking tape are used to bind the walls to the model baseboard. 1/2" X 2" furring and "2 x 4's" cut to short lengths make good wedges. For plaster casting, use regular Molding or Casting Plaster

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