There are several different processes for galvanizing steel.

#1 Hot-Dipped Galvanizing

As the name implies, Hot-Dipped Galvanizing process involves dipping the base metal into a molten pool of zinc.

Before the Zinc-bath, the base metal must be cleaned either mechanically, chemically, or cleaned with both methods to assure a quality combined with the zinc coating. Once cleaned, the base metal is then fluxed to rid it of any residual oxides that might remain after the cleaning process. The base metal is then dipped into a liquid bath of heated zinc and a metallurgical bond is formed.

Hot-dipped galvanizing is an economical method.

#2 Pre Galvanizing

Pre Galvanizing is very similar to Hot-Dip Galvanizing. But it is performed at the steel mill. The metal is then passed through a pool of hot, liquid zinc and then recoiled.

Compared to hot-dip galvanizing, Pre Galvanizing can rapidly galvanize large coils of steel sheet with a more uniform coating. A disadvantage of Pre Galvanizing is that once fabrication of the pre-galvanized metal begins, exposed, uncoated areas will become present. This means that when a long coil of the sheet is cut into smaller sizes, the edges where the metal is cut are left exposed.

#3 Electro-galvanizing

Electro-galvanizing does not use a molten bath of zinc. Instead, this process utilizes an electrical current in an electrolyte solution to transfer zinc ions onto the base metal. This involves electrically reducing positively charged zinc ions to zinc metal which are then deposited on the positively charged material. Grain refiners can also be added which helps to ensure a smooth zinc coating on the steel.

Similar to the pre-galvanizing process, electro-galvanizing is typically applied continuously to a roll of sheet metal.

Electro-galvanizing can provide a uniform coating and precise coating thickness. However, the coating is typically thinner than the coating of zinc achieved by the hot-dip galvanizing method which can result in reduced corrosion protection.