How To Make a Urethane Rubber Mold of Prop Gun


To cast multiple prop guns, PMC® 121-30 is an excellent mold rubber choice. The material is low shrinkage, easy to use (1:1 by volume mix ratio), and self de-airing. This application illustrates a cavity pour mold with a gypsum support shell. Ease Release® 200 is sprayed into the mold before the pigmented Smooth-Cast® 325 is cast.

Materials Used in this Tutorial

  • PMC® 121-30
  • Ease Release® 200
  • Smooth-Cast® 325
  • Mixing Sticks
  • Mixing Containers
  • Gypsum Support Shell
  • So-Strong

Step 1: Prop Gun Mold With Legs

In the picture below the mold is closed. Notice the legs used to hold the mold in a pouring position.

Step 2: Inside Of The PMC Mold

Here you can see the opened mold. One half of the rubber has been pigmented darker.

Step 3: The Original Model And Mold

The original model and opened mold.

Step 4: Side One Of The Mold

Notice the small rod, used to create a hollow gun barrel.

Step 5: Side Two Of The Mold

The surface detail captured is perfect.

Step 6: Casting

The resultant castings reflect perfect detail as well.