Zinc Coating Technical Information

Galvanised Zinc Coating Processes

There are three different zinc coating processes for steel, aluminium and other metals, each with high corrosion resistance and a variety of other benefits.
Before each of these processes, the metal parts must undergo surface preparation (in the form of either blasting or chemical pretreatment).

Note: DECO offers zinc flake coating onsite and can outsource zinc electroplating. We do not currently offer zinc phosphate coating.

Zinc Flake Coating

Zinc electroplating is a common finish which has been used for many years on products for internal use. Zinc electroplating can also vastly improve the appearance of metal components.

• The parts are sprayed with a liquid coating using conventional or electrostatic spray guns
• This liquid coating contains zinc and aluminium powders in the form of very small flakes; these flakes overlap to form a highly efficient galvanic coating
• For extra corrosion resistance or different colours, parts can be top coated with special sealers

As zinc flake coating is a liquid coating, it may fill small holes such as screw heads. It is therefore important to tape off parts you do not wish to be coated.

Zinc Electroplating

Zinc electroplating is a common finish which has been used for many years on products for internal use. Zinc electroplating can also vastly improve the appearance of metal components.

• First, the parts are cleaned and rinsed to remove surface contaminants
• The parts are dipped in a vat of specially-formulated zinc chemistry
• A DC current is applied at the anode to deposit the zinc onto the parts
• The product is rinsed and dried
• A post-plating conversion treatment can be applied to increase corrosion resistance

Due to the nature of the zinc electroplating process, the coating may not be deposited evenly across the product. The outer edges may acquire a thicker coating, while recesses may acquire a thinner coating or no coating at all.

Note: DECO offers outsourcing for zinc electroplating jobs, but does not perform this service onsite.

Zinc Phosphate Coating

Although zinc phosphate conversion coating has limited corrosion resistance on its own, it is often used as a pretreatment before painting or applying another surface treatment to metal components to greatly reduce risk of corrosion. It also offers greater resistance to the elements, reducing wear in metal parts. Zinc phosphate coating can improve paint adhesion to the surface of the metal parts, and is generally applied to steel components.

Note: DECO Australia does not currently offer zinc phosphating.

• The steel part is either dipped in a zinc solution, or the coating is applied with a spray gun
• When the metal comes into contact with the solution, a 'pickling' process occurs, creating a crystalline coating
• The parts are often post-treated with oils or other sealants

Quality Testing, Standards and Compliance

We test all our zinc coated products in our on-site Quality Testing lab. This ensures all our products comply with Australian Standards.

AS/NZS ISO 9001:2015

DECO Industrial complies with AS/NZS ISO 9001:2015: provision of metal finishing services (including zinc coatings). This ensures we comply not only with Australian regulations and requirements, but with customer expectations and specifications.

ISO 14001 Environmental Management System Certification

ISO 14001 ensures organisations and their processes and products comply with Australian environmental laws, and minimise their impact on the environment as much as possible. DECO Industrial is in the process of attaining this certification.