The process involved is:
Surface of steel structural is blasted by compressed air pressure with abrasives to remove all traces of rust or any foreign contamination and thus facilitate exposure of the base metal, within a few hours; the blasted surface is coated with zinc or aluminum. This is done by melting a zinc or aluminum wire in an electric arc or flame and atomizing the molten particles. These particles are then propelled by compressed air on to a blasted surface.
Additional sealant provides barrier protection to the surface. Though surface painting has to be done periodically for luster-retention, the basic aluminum coating remains intact and will protect the structure for years.
The advantages of Aluminizing and Spray Galvanizing in comparison to ordinary painting are as follows:
All metals have properties that cause them to react as an anode or a cathode when coupled to another material in a corrosive environment. The application of zinc / aluminum (anodic coating) to iron substrates forms a protective layer and results in corrosion protection referred to as cathodic protection or sacrificial protection.
Aluminizing or Spray Galvanizing provides well mechanical interlocking based on quality abrasive blasted pre-treated. Coating thickness of up to 500 microns can be applied though the industry standard is 100 – 150 microns. Aluminizing process is ideal in high temperature environment to prevent oxidation and corrosion. Coating with sealant provides a base for paints for longer life to structures.