An aftermarket remanufacturer of automotive generators, motors, starters, etc., was in search of a water-based coating to replace the solvent-based coatings that they had used for more than 50 years. Previously, a combination of protective solvent-based coatings had been used as part of their standard procedure. The function of the solvent-based coating (normally fast drying black paint) was not only to provide a new appearance to an old part, but also to protect against oxidation.
Due to environmental concerns, there was a need for a water-based coating that would provide the following:
• Eliminate solvents to comply with health and safety regulations.
• Improve the overall corrosion protection (extend shelf life by 6-12 months).
• Provide a protective coating that would enhance the natural appearance of the metal.
• Add corrosion inhibitor to allow for the coating to perform under conditions where the parts are not chemically cleaned and the surface is left with a residue from a wheel abrader.
Parts were placed in a large bulk-style basket and dipped into a bath of undiluted VpCI®-383. Parts were then removed and allowed to air dry for approximately 15-20 minutes. Cure time was one hour. Dry film thickness was 0.5 mils (13 microns).
Initial results showed that VpCI®-379 provided the required protection but the appearance was not acceptable (amber color). VpCI®-386 provided the desired appearance, but was unable to protect the poorly cleaned surface. VpCI®-383 was developed to meet the unusual requirements of enhancing the natural appearance of the part and protecting against corrosion on a contaminated surface.