Resin casting

Styrene is a similar liquid monomer at room temperature, which will also polymerize into clear glass-like polystyrene plastic, with addition of a suitable catalyst.

When the two part resin is mixed air bubbles tend to be introduced into the liquid which can be removed in a vacuum chamber.

The casting can also be done in a vacuum chamber (when using open molds) to either extract these bubbles, or in a pressure pot, to reduce their size to the point where they aren't visible.

The creation of a toy or figure start with the traditional sculpting process where the artist designs a clay sculpture.

Mixing the two liquid parts causes an exothermic reaction which generates heat and within minutes causes the material to harden, yielding castings or copies in the shape of the mold into which it has been poured.

Due to aggressive nature of most compounds used for casting and the high temperature of the reaction the mold gradually degrades and loses small details.

Typically, a flexible mold will yield between 25 and 100 castings depending upon the size of the part, the intensity of the heat generated.

The ability of RTV silicone molds to reproduce even the tiniest detail means that many of these low volume castings are of very high quality.