The hot dip galvanising process produces a durable abrasion resistant coating of metallic zinc and zinc-iron alloy layers bonded metallurgically to the steel base that totally cover your fabrication or component.
For most classes of steelwork hot dip galvanising provides the lowest long-term cost. In many cases it also provides the lowest initial cost.
An important point to remember is that during the process, the zinc coating becomes part of the steel surface it is protecting.
Galvanised coatings are abrasion resistant because zinc that is bonded to the steel serves as a sacrificial anode while protecting it. Even if the zinc coating is damaged through a scratch or other abrasion, the exposed steel continues to be protected cathodically by the remaining zinc. This is a key advantage of the process as a corrosion protection option. This unique metallurgical structure of the resulting coating provides outstanding toughness and resistance to mechanical damage in transport, erection and service.
The coating is subject to corrosion at a predictably slow rate, between one-seventeenth and one-eightieth that of steel, depending on the environment to which it is exposed.
An inherent advantage of the process is that a standard minimum coating thickness is applied even on sharp corners.
The coatings are virtually 'self-inspecting' because the reaction between steel and molten zinc in the galvanising bath does not occur unless the steel surface is chemically clean. A coating 'miss' is very easy to see if it occurs. Therefore a coating which appears sound and continuous is sound and continuous.
Galvanising today remains a highly versatile process: Items ranging from small fasteners and threaded components, up to massive structural members can be coated either with a hot dip, or centrifuge process. The mechanical properties of commonly galvanised steels are not significantly affected by the process.