Birchwood Casey’s Clearlok Max Topcoat is a water-based blend of acrylic polymers that forms a scuff-resistant, clear-coat finish on virtually all metal surfaces. Typical finish applications include hand tools, machine components, power transmission components, pumps, valves and oilfield equipment. The densely packed polymer structure forms a tightly adherent barrier against corrosion while enhancing the durability of the surface. The topcoat is well-suited for black oxide or other surface coatings, such as phosphates and antique finishes, the company says. It can also be applied directly to clean or shot-blasted metal surfaces such are bare steel, aluminum, nickel and zinc plating.
Supplied as a liquid concentrate, the coating is pH neutral, non-hazardous and safe to apply without ventilation. The concentrate is diluted with water, applied to parts by immersion and dried at 70° to 130°F, achieving a nominal film thickness of about 0.002". Once dry to the touch, the parts are ready for assembly or packaging. Full hardness is achieved in about 24 hours.
Minimum humidity resistance is 400 hours (ASTM D1748), depending on film thickness.
For applications requiring extra corrosion resistance, the dried finish can be sealed with Dri Touch rust inhibitor to create an even more impervious barrier against humidity and corrosion.