Gasket Maker Gray is a sealant that hardens at room temperature. Extremely resistant to extreme temperatures. Creates a reliable seal that does not crack, shrink or shift under the influence of sudden temperature changes. Replaces o-rings, washers, and asbestos, rubber, felt, paper, cork, and metal seals. It can be effectively used for repair of: valve guide bushings, oil pans, thermostat housings, etc. Resistant to lubricants, coolants, gasoline, kerosene, water, acids and alkalis. Easy to apply and remains flexible. The surface to be treated must be degreased