Cast-a-Mold silicone thinner is a dimethyl fluid with a viscosity of 50 cps. This thinner will be compatible with any of our silicone rubbers. Lowering the viscosity of a mold making rubber will allow the silicone to flow more easily into smaller detailed areas. We recommend only adding 3% to 5%. Adding too much silicone fluid can adversely effect the physical properties of the silicone itself. Tear and tensile strength will be lowered if too much silicone thinner is used. The thinner can also be used to help replenish the life of a silicone mold. We recommend brushing a small amount into the mold before storage.