J-B Weld ultimate copper silicone gasket maker and sealant is an RTV (Room Temperature Vulcanized) silicone gasketing material that is 3 times more oil resistant than conventional silicones and designed to resist the high operating temperatures of turbocharged or high-performance engines. Ultimate Copper is effective in temperatures from -75F to 700F intermittent. Upon curing, which occurs when the product is exposed to the moisture in air, the silicone forms a tough, waterproof seal on most surfaces. It will not shrink or crack, resists weathering, is sensor safe and is great for many automotive applications.
Advanced high temperature RTV sealant adhesive.
Designed for high operating temperatures.
Three times more oil resistant.