Degreasing

A mild acidic or biological cleaning bath removes organic contaminants such as dirt, grease, and oil from the metal surface. Epoxies, vinyls, asphalt, or welding slag, which cannot be removed by degreasing, must be removed before galvanizing by grit-blasting, sand-blasting, or other mechanical means.

Pickling

A dilute solution of ambient hydrochloric acid removes mill scale and iron oxides (rust) from the steel surface. As an alternative to or in conjunction with pickling, this step can also be accomplished using abrasive cleaning or air blasting sand, metallic shot, or grit onto the steel. 

Fluxing

The final surface preparation step in the galvanizing process, a zinc ammonium chloride solution, serves two purposes. It removes any remaining oxides and deposits a protective layer on the steel to prevent any further oxides from forming on the surface prior to immersion in the molten zinc.

American Galvanizers Association

As a member of the American Galvanizers Association (AGA) Southern Galvanizing is happy to share the many useful resources offered by the AGA website.