Loctite 5940 black silicone sealant 100ml loctite 5940 p loctite 5940 sealant is primarily used as a general purpose sealing and bonding agent as a space filling rubber adhesive or formed in place gasket it cures on exposure to moisture in the air to form a tough flexible waterproof oil resistant silicone rubber bond p p the sealant adheres to clean metal glass most types of non oily woods silicone resin vulcanized silicone rubber ceramic natural and synthetic fibre and many pa