Loctite SI 5699 is a flexible silicone sealant and cures on exposure to moisture in the air to form a tough rubber gasket. The product is designed primarily for flange sealing with excellent oil resistance or rigid flange sealing for example on transmissions and cast metal housings. It is tack-free after just 10 min. The product is water-glycol resistant and can be used on machined or cast surfaces, metal or plastic.