How To Spray Paint Galvanized Sheet Metal

Possible cause new galvanized metal a product used to make corrugated sheets gutters and downspouts is usually smooth and is coated with either a layer of oil to prevent white rust or is passivated.

How to spray paint galvanized sheet metal.

For the most dependable results look for paints that are formulated specifically to bond to galvanized steel. On older galvanized metal surfaces where the zinc coating has begun breaking down known as white rust use a wire brush or fine sandpaper to remove the chalky film before cleaning it. Galvanized metal is difficult to paint because it s coated with a layer of oil to prevent white rust. Once the metal has dried dampen a cloth with white vinegar and wipe the surface down.

Paint that has lost its adhesion to a galvanized metal substrate e g. When painting galvanized steel all paint systems used should be specifically formulated for use on galvanized steel and applied in accordance with the paint manufacturer s recommendations. The painting process is actually very straightforward because the surface of galvanized steel is relatively smooth and consistent. Galvanized steel is a great material to use for a variety of tools products and projects and it s environmentally friendly.

It also has surface contaminants oils greases residues etc left on the surface from the manufacturing process that interfere with the adhesion of paints. Avoid using alkyd based paints such as spray paint on galvanized steel. The enamels in alkyd paints can react with the slick zinc finish on a galvanized steel surface leading to poor adhesion and peeling. The choices of paint for galvanized metal will depend upon both the application and service environment.

The acid in the vinegar will act to etch the metal and help the paint adhere. Alkyd and oil based paints may seem to stick at first but the oily layer eventually sheds the paint.