Galvanising Process

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 and completely covering the work piece.

For most classes of steelwork hot dip galvanising provides the lowest long-term cost. In many cases galvanising also provides lowest initial cost.

The hot dip galvanised coating becomes part of the steel surface it protects.

The unique metallurgical structure of the galvanised coating provides outstanding toughness and resistance to mechanical damage in transport, erection and service.

The galvanised 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.

Galvanising's cathodic protection of steel ensures that small areas of the base steel exposed through severe impacts or abrasion are protected from corrosion by the surrounding galvanised coating.

An inherent advantage of the process is that a standard minimum coating thickness is applied even on sharp corners.

During galvanising the work is completely immersed in molten zinc and the entire surface is coated, even recesses and returns which often cannot be coated using other processes.

Galvanised 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. Therefore a hot dip galvanised coating which appears sound and continuous is sound and continuous.

Galvanising is a highly versatile process. Items ranging from small fasteners and threaded components, up to massive structural members can be coated.

The mechanical properties of commonly galvanised steels are not significantly affected by galvanising.

Galvanising provides outstanding corrosion performance in a wide range of environments.

Duplex coatings of galvanising-plus-paint are often the most economical solution to the problem of protecting steel in highly corrosive environments. Such systems provide a synergistic effect in which life of the combined coatings exceeds the total life of the two coatings if they were used alone.