Hot-dip galvanizing (HDG), as referenced on this site, is the process of dipping fabricated steel into a kettle or vat containing molten zinc. The process is inherently simple which provides a distinct advantage over other corrosion protection methods. While the steel is in the kettle, the iron in the steel metallurgically reacts with the molten zinc to form a tightly-bonded alloy coating that provides superior corrosion protection to steel.
The information throughout this section on durability, longevity, cost, and sustainability applies only to the hot-dip galvanizing (commonly referred to as batch, general, or after-fabrication galvanizing). It is important to understand not all zinc coatings are created equally; thus, applying any of the information provided about hot-dip galvanizing to other zinc coatings is not accurate or recommended.
To understand the hot-dip galvanizing process and its evolution, it makes sense to start at the beginning, which dates all the way back to 79 AD.