Casting molds: investment, rubber, silicone and sand

The mold is the structure into which molten metal is poured to give it form. Depending on the casting technique, the mold can be single-use or reusable.

Investment mold (lost wax) #

Made by covering the wax model with a refractory plaster inside a flask; when heated, the wax melts out and leaves the cavity. It is single-use (see lost-wax casting).

Rubber and silicone molds #

Used to make copies in wax (injection) or in resin, tin and pewter. They are flexible and reusable. Vulcanized rubber molds withstand thousands of copies.

Sand mold #

A mix of sand and binder packed around a pattern; used for simple pieces. See casting.

Ingot molds #

Of steel or graphite, to cast metal into bar form.

Care #

Keep rubber and silicone molds clean, flat and away from heat and light.

See also #

• Casting
• Lost-wax casting
• Casting crucibles: types, uses and care