Hot Dipped Galvanizing
Hot Dip Galvanizing is one of the most cost-effective methods of coating steel, given its long protective life span.
Almost all Webforge products are available galvanised, either in-house or through fellow Valmont Company, Industrial Galvanizers
. Webforge NZ has an in-house Galvanising facility in its Palmerston North plant. All Galvanizing is carried out to AS/NZ4680.
Galvanizing is the practice of immersing oxide free iron or steel into molten zinc in order to form a zinc coating that is metalurgically bonded to the substrate's surface.
The zinc coating protects the surface against corrosion:
- By shielding the base metal from the atmosphere, and
- Because it is more electronegative than iron or steel, the zinc provides cathodic or sacrifical protection
Even if the surface is scratched, exposing the base metal, the zinc is slowly consumed while the iron or steel remains protected from corrosion.
The hot dip galvanizing process is adaptable to coating nearly any product including tanks, sheets, strip, pipes and tubes, fittings, hardware, wire cloth, hollow ware, and structural assemblies.
Galvanizing consists of four fundamental steps:
- Surface Preparation - cleaning and pickling to free the surface of dirt, grease, rust and scale
- Prefluxing - to dissolve any oxide that may have formed on the substrate surface after pickling, and prevents further rust from forming
- Galvanizing - clean, oxide free items are immersed in the molten zinc