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What is Galvanization?

Galvanization, or Galvanization, is the process of applying a protective zinc coating to steel or iron, to prevent rusting. The most common method is hot-dip galvanization, in which parts are submerged in a bath of molten zinc. 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) which is formed by the reduction and oxidation reaction of iron and oxygen, in the presence of water or air moisture.

It forms a coating of corrosion-resistant zinc which prevents corrosive substances from reaching the more delicate part of the metal the zinc serves as a sacrificial anode so that even if the coating is scratched, the exposed steel will still be protected by the remaining zinc.

Types of Galvanization

• Electro galvanization – In this type of galvanizing process, the raw metal is submerged into an electrolyte solution, in which the anode is composed of zinc. As the process of electrolysis happens, current starts flowing into the metal from the zinc anode and particles of zinc get coated on its surface. However, this protection is both uneven and pretty thin but boasts a shiny appeal. Moreover, the process does not follow any rigid cleaning procedure of the raw metal before the electrolysis, which tends to impurities getting stuck on the surface of the metal.

• Hot-Dipped Galvanization – This procedure is preceded by a series of cleaning and rinsing steps to get rid of all impurities. The wire is first cleaned in a caustic solution to do away with scales and impurities, following which it is rinsed thoroughly, and a non-oxidized compound, or flux, is added to it. Thereafter, the wire is immersed in molten zinc at a temperature range of 443 – 465° Celsius, or 830 – 870° Fahrenheit. As the result of a chemical reaction between iron and zinc, a layer of pure zinc gets deposited on the surface of the wire, thus creating a protective layer on it. Although the hot-dipped galvanized steel wires are not as shiny as the electro galvanized ones, the coating is thicker and less impure. Guess all that shine are not really gold after all!

• Cold Galvanizing – Well, basically, this has less to do with galvanization and more with painting. It involves applying a resin-based zinc varnish on the steel wire to form the protective layer of coating. However, it is quite ineffective in terms of abrasion resistance and has the lowest service-life than the aforementioned types of galvanizing process. The term is used for marketing purposes basically; otherwise, cold galvanizing is all about painting the steel wires with zinc-enriched paint.
 

Primary Benefits of using Zinc Coding

1. Lower cost than stainless.
2. Less maintenance/Lowest long term cost.
3. Long life expectancy.
4. Coating life and performance are reliable.
5. Outstanding resistance to mechanical damage.
6. Protection to small areas of steel exposed through damage.
7. No other coating can provide the same protection.
8. No lost time in surface preparation, painting and inspection.

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