Technical Info | What are Zinc-rich Paints
Zinc-rich Paints

Brite Zinc - brush imageZinc-rich paints have long been recognized for their excellent paint adherence to both new and weathered galvanized surfaces. Zinc-rich paints have been used in the U.S. for more than 75 years and in Europe for well over a century. One of the key reasons for the success of zinc-rich paints is their barrier and cathodic protection. In a 1960s study by the American Iron and Steel Institute and the Steel Structures Painting Council, zinc-rich paints outperformed all other classes of paint. Significantly, at the nine-year inspection in 1970, there was no loss of adhesion to  Zinc-rich paints have long been recognized for their excellent paint adherence to both new and weathered galvanized surfaces. Zinc-rich paints have been used in the U.S. for more than 75 years and in Europe for well over a century. One of the key reasons for the success of zinc-rich paints is their barrier and cathodic protection. In a 1960s study by the American Iron and Steel Institute and the Steel Structures Painting Council, zinc-rich paints outperformed all other classes of paint. Significantly, at the nine-year inspection in 1970, there was no loss of adhesion to the zinc surface.

Zinc-rich paints possess similar characteristics to a hot-dip galvanized zinc coating. With a high percentage of zinc in the dry film (i.e., after cure), these paints can synergistically combine with the corrosion inhibitive properties of metallic zinc. The zinc dust in paint is integrated with organic binders. These binders allow the zinc particles to remain in contact with each other so the zinc paint can provide cathodic protection.

Zinc-rich paints are an accepted method of repairing damaged galvanized coatings according to ASTM A 780. Zinc-rich paints containing at least 65% zinc meet the specification designations. They are widely used for touch-up and repair of damaged galvanized coatings because of their relative ease of application.

Although zinc-rich paints are useful as primers to gain surface adherence, they are also satisfactory as a finish coat when a neutral or matching color is desired (see Brite Zinc description).

These paints can be used alone, but for a more attractive finish, a topcoat is often employed. While most top coats are easily used, some with very strong solvents may result in a lifting of the primer. Successful topcoats include polyvinyls, acrylic latexes, polyurethanes, and polyamid cured epoxies. DO NOT USE LACQUERS OR ALKLYD-BASED TOPCOATS AS THEY REACT NEGATIVELY WITH ZINC-RICH PAINTS. Specific manufacturer's recommendations should be followed for application and topcoating.