PoYo Silicone Mold Making Putty - Trial Unit Easy to use tin-cure silicone mold putty that is mixed and applied by hand. Mix Ratio: 100A:6B by weight or 20A:1B by volume Pot Life: 3-5 minutes - Cure Time: 30 minutes (Pot life and cure time can be adjusted (faster or slower) by varying the amount of Part B catalyst.) Shore 40A Hardness PoYo Putty has been used to make molds of valuable antiques and archeological models and can be used to make fast molds of sculpture, prototypes, candles, picture frames, coins, etc. You can cast wax, gypsum and a variety of resins into PoYo Putty molds.