Molding and Casting with Smooth-On Products!

PunishedPropsArticles - Written, Blogs, Casting, Materials, Molding & Casting


I am frequently asked which molding and casting materials I use for my props and costumes. It’s different for every project, but for the Kaijudo Gauntlet build, I used all Smooth-On products.

The molds were made with Rebound 25 silicone. It’s a brush on, platinum cure silicone that is fantastic for making these kinds of molds. I first put on a thin “print coat” of silicone, then added a couple more layers for strength. The last layer had a thickener added to the silicone so that it was easier to brush, giving it a bit of an icing consistency.

The “mother mold” was made using Plasti-Paste II. This “trowelable” plastic makes a hard, removable shell around the silicone so that it retains it’s basic shape. I built these in two parts to make them easier to pull off the mold.

The gauntlet pieces were cast in Smooth-Cast 65D. This is a polyurethane plastic resin with about a 2.5 minute pot life. This means you mix it up, dump it in the mold, and then have a couple minutes to slush it around the inner surface of the mold before it hardens. This way your piece only has plastic on the surface and isn’t a massive, solid block. For these pieces I slushed 4-5 layers of plastic to get the wall thickness I wanted. I also added a black SO-Strong tint to the plastic resin before mixing it up.

This particular project employed “cold casting” with metal powders. Check out the video for the full build!

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