Since 1946

Hot-dip galvanizing is used to protect steel from corrosion in a variety of environments, including air, water, soils, and chemical applications. The performance of the galvanized steel in these applications is dependent upon a set of corrosion variables. The most common applications are found in the atmosphere or open air.

In atmospheric applications, the galvanized steel develops of a series of films on the zinc surface known as the patina. It does this by being naturally exposed to wet and dry cycles. The patina then needs to be exposed to aggressive chlorides or sulfides. This is a key component to galvanizing’s long life.

A variety of independent and industry tests of galvanized steel samples have been performed over the past few decades, in numerous environments, to determine the life of the product until maintenance will be required.

The American Galvanizer’s Association’s website contains resources regarding the durability of galvanized steel. Please note the performance data on their site is based on actual performance in the field, and not on accelerated testing methods. Manufacturers of other corrosion protection systems use these accelerated tests, which usually involve salt spray tests, to claim their products perform as well as hot-dip galvanized. What they fail to mention is that salt spray tests do not allow the zinc coating to go through the natural wet and dry cycles necessary to form the zinc patina.

American Galvanizer’s Association Specifier’s Guide