12 Red RTV Silicone Gasket Maker High-Temp Instant Sealant for AUTO GASKET 3.0oz. Uncured sealant causes eyes skin irritation. Assemble part once silicone has skinned 8 to 12 minutes. Our gasket line is made of non-asbestos material, the best rubber, stem seal, graphite or MLS (multi-layer steel) head gasket for superior sealing.