3M™ Scotch-Weld™ anaerobic activator AC649 is an acetone-based green surface activator/primer that cures anaerobic adhesives on inactive or very cold surfaces. For normal active surfaces, this activator accelerates both fixture and cure times significantly. 3M™ Scotch-Weld™ anaerobic activator AC649 increases the cure rate of anaerobic adhesives, especially on inactive metals, such as plated parts, anodized aluminum, stainless and galvanized steel. It can be pre-applied up to 30 days in advance and can be used with 3M™ Scotch-Weld™ thread lockers, pipe sealants, retaining compounds and gasket makers. Anaerobic adhesives are uniquely formulated to cure in the absence of oxygen. The term \"anaerobic\" means \"living without air\" and when the oxygen is excluded, a chemical chain reaction begins that causes the adhesive to polymerize. Contact with metal speeds the polymerization process and rapidly accelerates the curing process, forming tough cross linked plastic that provides aggressive adhesion with effective shear strength. More commonly referred to as thread lockers, pipe sealants, retaining compounds and gasket makers, these adhesives are often used to enhance the seal or holding force, in the threads of joined fastener systems such as nut-and-bolt assemblies. A nut-and-bolt assembly may have as little as 15% metal-to-metal contact and even a small amount of anaerobic adhesive readily fills any air voids between the threads and then hardens to a thermoset plastic. These unique adhesives are easy-to-dispense, cure rapidly and provide effective torque strength while resisting temperature and vibration and sealing out moisture and gasses to protect against corrosion. Anaerobic adhesives can decrease manufacturing costs, enhance equipment reliability, minimize aftermarket breakdown and reduce warranty claims. Scotch-Weld™ 7010367620, 1-Part, Bottle Container, 8 oz Container, 5 min Setting, 24 hr Curing, Green, 0.79 Specific Gravity, 1 g/L VOC, 2 cPs Viscosity