One of the most commonly used type of industrial coatings is the zinc coating which gives an aesthetic finish to the metal on which it is applied in addition to the corrosion resistance aspect. The zinc may be used together with lacquers, seals and waxes for a better finish. Even though zinc is also a metal, whenever it is exposed to different environmental elements, it forms a protective film and this is why it is deemed as a good option when it comes to coating other metals. Once the zinc is electrified, it adheres to the steel surface and the metal underneath is consequently protected against corrosion.
The amount of protection offered by the zinc coating is dependent on the thickness of the plating. Compared to a thick coating, a thin one rusts at a faster rate. Still, the corrosion rate is much slower than that of steel, even where both metals are exposed to water or other environmental conditions. Although the zinc may appear to rust first, it forms a coating which subsequently impedes further rusting. Due to this useful element, zinc coating is commonly used in construction sites, welding sites and storage facilities. It is also applied in the manufacturing of steel girders and car parts.
Zinc coating may be applied through a number of processes including continuous hot dip galvanizing, hot dip batch galvanizing and electrolytic galvanizing. In continuous hot dip galvanizing, a rolled sheet is dipped in molten zinc. Steel coated using this method is often used on roofs, silos, air ducts and car parts. Hot dip batch galvanizing on the other hand is applied in items such as road barriers, street furniture, lighting poles, advertising poles and garden frames. The galvanization process in this case also involves immersing the steel into a bath of molten zinc. Electrolytic galvanizing is quite popular though more and more industries have moved towards continuous dip galvanizing due to market preferences in addition to the operating costs associated with the process.