PlatSil® 73-40 Silicone Rubber
PlatSil® 73-40 is a mid-range hardness (A40) platinum silicone rubber designed for making long-lasting, flexible molds to cast liquid plastics or rubbers (polyurethanes, polyesters and epoxies) as well as polyurethane foams.
PlatSil 73-40 can also be used to cast waxes (foundry applications or candles), plasters (gypsum or fiber-reinforced gypsums), soaps, and all varieties of concrete (wet-casts, glass-fiber reinforced concrete-GFRC). Since PlatSil 73-40 has no shrinkage upon curing and resists mold distortion due to casting, it is an ideal product where dimensional stability is required.
PlatSil 73-40 is a 1A:10B mix and has a yellow-colored Part A for easily identifying when material is properly mixed. PlatSil 73-40 also has Polytek’s signature high, knotty tear strength and offers excellent chemical resistance and elongation as well. As with all Polytek silicone mold rubbers, PlatSil 73-40 allows casting to be done without release agents in most cases.
Pour as supplied or thicken for brush-on molds using PlatThix liquid thickener.
|Mix Ratio||Shore Hardness||Pour Time||Cured Color||Mixed Viscosity||Specific Volume||Demold Time|
|1A:10B||A40||45 min.||Yellow||25,000 cP||22.0 in³/lb||16 hr.|
|Accessories: PlatThix Liquid Thickener, PlatSil® 71/73 Part R Retarder, Silicone Fluid 50cs, PlatSil® 71/73 Part X Accelerator|
Video Tutorials on YouTube: How to Make a Two-Piece PlatSil 73-40 Block Mold | How to Make a Mold of a Decorative Tabletop & Cast Concrete. For other video tutorials, visit the Polytek YouTube Channel.
Blog Tutorial: How to Make a One-Piece PlatSil 73-40 Block Mold