BLK HI TEMP SEALANT: Seal inner pipe on direct vent units, fireboxes, burners, pellet stove venting or blowers. Easy appliance removal for inspection. This product is not an adhesive. Use proper mechanical fastners to secure assembly. Easy-to-apply sealant for installation and maintenance of direct vent gas burning systems. Seals gas duct and pipe flanges, as well as the firebox of direct vent fireplaces. Use for sealing vent applications with pellet stoves. It flows to create a homogeneous gasket in operating temperature up to 800 F. Harsh pungent odors will not be emited as with some other high temperature sealants. Tough and flexible with air curing and further hardens with heat. It resists vibrations, cracking, fumes, gases, moisture and acids formed by gas combustion by-products. Does not shrink or turn brittle. Clean up with water within 15 minutes.