Loctite (37509) Klean N Prime Activator Part No: 494147

The 494147 Klean ’N Prime Activator (Loctite 37509 / 7649) is engineered to prepare difficult-to-bond metal surfaces for anaerobic adhesives. Its solvent-based formulation works on otherwise “inactive” or plated substrates — such as stainless steel, gold, silver, aluminum, zinc, or passivated surfaces — by promoting a proper cure. 



This activator not only speeds up the cure time of Loctite anaerobic products but also boosts the bonding strength (break-away torque) on metals that normally struggle to cure fully. 

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It’s particularly useful in low-temperature environments (below 5 °C / 41 °F), where standard anaerobic adhesives may cure too slowly. 

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Apply a light coat, allow it to flash (dry briefly), then apply your threadlocker, sealant, or gaskets. Use cases include valve covers, intake manifolds, fasteners (2.2 mm to 12 mm), AC belt brackets, and more.