Hot Dip Galvanizing Or Acid Passivation

Zinc Is A Sacrificial Layer

Hot-dip galvanizing puts a zinc coat on carbon steel that corrodes instead of the steel underneath. It is immersion, so it reaches cut ends, hook welds and the inside of banding. That is why panels here are galvanized after fabrication rather than before.

Passivation Restores A Layer That Was Already There

Stainless steel protects itself with a passive chromium oxide film. Cutting, welding and handling damage that film. Acid passivation removes free iron and lets the film reform across the whole fabricated panel. It adds nothing on top of the steel.

What Kills A Zinc Coat

Chlorides and cleaning chemicals. A washdown floor in a food plant, a pool surround or a coastal promenade will strip zinc far faster than weather alone. That is the case for stainless, not the strength of the panel.

What Kills Stainless

Skipping the passivation, embedding carbon steel particles with the wrong tooling, and mixing metals at the fixings. Stainless grating that rusts almost always rusts at a weld, a cut end or a fixing.

The Other Two Treatments

This plant also produces electroplated galvanizing, a thinner brighter zinc for sheltered duty, and painting, which belongs over a galvanized coat rather than instead of one.