A wide variety of coatings can be used on the surface of zinc zinc parts, and sometimes the choice depends on the method of surface preparation. However, some coatings cannot be used on zinc locks, especially oil-based alkyd paints.
There are many kinds of epoxy paints, and they need to be specially used for locking zinc parts, and polyamide curing epoxy paints are usually used. Epoxy will chalk in the sun, so the topcoat is better coated with an aliphatic polyurethane topcoat that looks good and is chemical resistant.
Water-based acrylic paints dry quickly, make great top coats, and are easy to suan. However, although water-based latex paint dries quickly, it takes 2-4 weeks to fully cure. Therefore, in the initial period, their adhesion and wear resistance are poor. For new construction, handling damage may occur.
Chlorinated rubber and vinyl coatings have been used on zinc locks in the past, but environmental regulations regarding VOCs have limited their use. The surface of the locked zinc part after sweeping sand treatment and phosphating primer has good adhesion.
Acrylic paint can be directly painted on the surface of the zinc lock, of course, it is better to have a phosphating primer as a primer.
Some acrylic paints contain ammonia, which can cause the coating to peel if the pH is high. If the zinc lock is buried in the ground, it can usually be coated with epoxy bituminous paint or pure epoxy paint, and it is better to coat the surface with sweep sand treatment or phosphating primer. Epoxy zinc rich paint can usually be applied directly to the surface of zinc lock parts, but not all epoxy zinc rich paints can be used, please check the supplier's paint product specification.
If the surface is prepared by sweep sanding, it needs to be painted within 24 hours, because the fresh zinc layer will start to oxidize. Applying a phosphating primer or acrylic passivator first will give us enough time to paint.
