Clearlok from Birchwood Technologies is an “all-purpose” water-based polyurethane sealant formulated to provide a protective topcoat on most metal surfaces. Clearlok produces a clear, hard and glossy sealant that is said to offer scratch and scuff resistance and long-term corrosion protection. It is suited for black oxide finishes on iron and steel; black finishes on aluminum; and non-finished iron, steel and aluminum surfaces.
The sealant produces a final coating thickness of 0.0001 to 0.00003 inches, and it is rated for corrosion resistance of 12-24 hrs of neutral salt spray or more than 100 hrs of humidity exposure. It contains no harmful VOCs and is supplied as a heavy-bodied liquid that can be diluted with water for application using immersion tank processes or for easy brush-on application. According to the company, it can be easily implemented on most plating and finishing lines. Clearlok can dry quickly at room temperature or can be force-dried using warm air.