AC SmartSeal External is a leak stop suitable for any material. It effectively seals all types of leaks up to 5 mm. Specifically designed to be inert to all kinds of lubricants and gases, External does not react to temperature changes, making it a superior external leak sealer. Easily mixed by using two fingers. Once applied, the leak is closed. It is ideal for emergency sealing and does not disperse any residue into the system and, if necessary, it can be easily removed and once dried, the product can be sanded and refinished. Instructions for Use: Find the leak by using the usual detection methods. Once the leak is identified, turn off the system, and clean the application area. Cut with a knife a quantity of SmartSeal External which is enough to create a ring around the entire diameter of the pipe in the area of the leak. Using your fingers mix the two components for a while. The color must be uniform and you should perceive a slight sensation of heat. Apply the mixture directly on the leak area, let it adhere to the whole circumference with about .5 inches on each side of the leak area. Wait 4-5 hours for the SmartSeal External to cure and harden. Curing can be accelerated with the use of a heat gun. Once the product is dried, let the system run normally again.