The best Chemical Sealer you can buy to stop cooling system leaks Works equally well in aluminum or cast iron blocks Cooling system must be thoroughly clean before use Does not work with antifreeze If this doesn't stop the leaks, find yourself a welder! WARNING!#MOR35500 and #MOR35520 - Avoid contact with eyes or skin. Do not take internally. If splashed on skin, wash thoroughly with cold water. If splashed in eyes, flush thoroughly for 15 minutes with cool water and consult a physician. If taken internally, drink 3 or 4 glasses of milk or water. DO NOT induce vomiting. Call a physician immediately. Always keep out of reach of children. In an emergency, call the Poison Control Center. Seattle: (206) 526-2121Denver: (303) 739-1123Pittsburgh: (412) 681-6669Pit Stop USA offers Moroso Ceramic Engine Seal - One Pint Plastic Bottle 35500 at low everyday prices. Be sure to check out all of our products from Moroso Performance Products including Moroso Performance Products Coolant Additive and Moroso Performance Products Coolant Additives.