What Is Galvanization?

Galvanization is the process of applying a protective zinc coating to steel or iron in order to prevent premature rust and corrosion. Proponents of galvanized steel, who may use it to construct or repair steel structures, for example, benefit from lower maintenance and repair costs because of its special properties.

Without protection, steel will rust due to atmospheric conditions over time. The degree of rust will depend on the environment that the product is in. Rust is an iron oxide (typically a red oxide) that is formed by the reduction and oxidation reaction of iron and oxygen, in the presence of water or air moisture.

There are protective methods such as painting or plastic coating, but these methods do have drawbacks. When damaged, sections of the steel will become rusty and the protective coating will fall away, making these types of protection non-lasting and unreliable (always needing continued maintenance).

One of the better methods of protecting steel materials against corrosion is through hot-dip galvanization. With hot-dip galvanization, all the surfaces of the material are dipped into, and completely coated with, molten zinc.

The corrosion of zinc is very slow, which gives it an extended life while it protects the base metal. Due to the alloying of the Zinc to the iron, cathodic protection occurs. This ensures that small areas of steel that may be exposed through damage are not compromised by rust. Unlike organic coatings, small damaged areas need no touch-up. The cathodic protection will last as long as the zinc layer is present.

Take special care if your project requires contact between any galvanized material and copper or brass. This is especially true in a moist or humid environment as rapid corrosion of the zinc could occur. Water running off a copper or brass surface could have enough dissolved copper in it to cause rapid corrosion. If this applies to your situation, prevent it by ensuring the water flows from the galvanized material to the brass or copper parts.

The primary advantages for using Galvanized include:

#1 Long life expectancy.

#2 Lower cost than stainless.

#3 Coating life and performance are reliable. 

#4 Less maintenance/Lowest long-term cost.

#5 Outstanding resistance to mechanical damage.

#6 No other coating can provide the same protection.

#7 Protection to small areas of steel exposed through damage.

#8 No lost time in surface preparation, painting, and inspection.