Rubber Mold Casting

Casting metal alloys in rubber molds is a popular method for creating complex and intricate metal parts. The process involves pouring molten metal into a rubber mold, which is then allowed to cool and solidify, resulting in a finished part. Generally, metals must have a low melting temperature.

Rubber mold casting is often done as a centrifugal casting (See: Rubber Mold Spin casting), but can be done as a gravity fed process.

Project by Lucas Rivers, The University of Memphis.

A rubber mold used to cast tin alloy. Mold by Lucas Rivers
Mold Material: Smooth-on Moldmax 60
Alloy: Tin with 4% Copper and .04-.2% Selenium

Rubber molds are ideal for casting some metal alloys due to their flexibility and ability to reproduce fine details. The mold is typically made from a silicone or urethane rubber material, which can withstand the temperatures involved in the casting process.

To begin the casting process, the rubber mold is first prepared by applying a mold release agent to ensure that the finished part can be easily removed from the mold. The mold is then heated to a temperature appropriate for the type of metal being cast.

Once the mold has reached the desired temperature, the molten metal is poured into the mold cavity. The metal fills the mold and takes on the shape and details of the mold cavity. The mold is then allowed to cool and solidify.

After the metal has solidified, the mold is opened and the finished part is removed. The excess rubber material is trimmed away from the part, and any rough edges are smoothed out using sandpaper or other tools.

Casting metal alloys in rubber molds offers several advantages over other casting methods. First, it is a cost-effective method for producing small to medium-sized batches of parts. Second, rubber molds can be easily modified or replaced, allowing for changes in the part design without incurring significant costs. Finally, rubber molds are capable of producing intricate and detailed parts with consistent quality.