How To Spray Paint Galvanized Sheet Metal

For the most dependable results look for paints that are formulated specifically to bond to galvanized steel.

How to spray paint galvanized sheet metal.

The choices of paint for galvanized metal will depend upon both the application and service environment. The problem with painting galvanised metal is that the surface when new is very shiny and smooth making it difficult for paint to stick to the surface. Galvanized metal is difficult to paint because it s coated with a layer of oil to prevent white rust. Alkyd and oil based paints may seem to stick at first but the oily layer eventually sheds the paint.

Avoid using alkyd based paints such as spray paint on galvanized steel. The painting process is actually very straightforward because the surface of galvanized steel is relatively smooth and consistent. 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. Once the metal has dried dampen a cloth with white vinegar and wipe the surface down.

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. The surface that has been painted. It also has surface contaminants oils greases residues etc left on the surface from the manufacturing process that interfere with the adhesion of paints. Paint that has lost its adhesion to a galvanized metal substrate e g.

The acid in the vinegar will act to etch the metal and help the paint adhere. 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.