How a Zinc Protective Coating Protects Your Fence How a Zinc Protective Coating Protects Your Fence
Chain link fences are an inexpensive way to protect property and with the right protective coating they can last for decades. When considering installing a chain link fence, the materials that you choose will determine how well your fence ages.
Zinc Plating vs Galvanizing
Both zinc and galvanized protective coatings use zinc. The difference is in the thickness of the coating. The thickness of a zinc coating is 3 microns. Galvanized materials are dipped in molten zinc and the coating is typically 50 microns. A galvanized fence may get scratched or may have exposed edges but the zinc in the coating will still protect the fence. The reason for this is that there is a current that is generated by the corrosive elements reacting with the zinc. The corrosion acts on the zinc in the coating instead of the metal in the fence. If a wire on the fence is cut the zinc will develop an oxidation layer over the cut area and this protects it from rust.
If a fence is already installed then a zinc primer can be applied and then it can be painted. This primer is usually marked “cold galvanizing." Paint alone is a good protector until the surface is broken or water gets in via the edges. This moisture will corrode the metal. Applying a thin coat of this primer will protect the fence.
Zinc Sacrificial Anodes
Anodes of this kind have been used by ships and boats for many years. In the same way that a galvanized fence is protected by its zinc coating, a zinc anode will attract the corrosive elements. It “sacrifices” itself to protect the metal of the fence. Zinc anodes can be placed along the fence to add protection from rusting and corrosion.
How Chain Link is Galvanized
There are two methods of galvanizing chain-link fencing. GAW (galvanized after weaving), as its name suggests, means that the steel is woven into chain-link panels first and then the coating is applied. The other method is GBW (galvanized before weaving). Each steel wire is galvanized before it is woven into chain link. As the chain link is woven or welded it may burn off some of the zinc leaving areas that are vulnerable to rust. GAW covers cut ends and welded or woven points and increases its strength. GAW is the most common and the most durable.
Chain link fence fittings include the nuts, bolts, gate hardware and other hardware used to construct the fence. It should also be protected by galvanizing. Not all fittings have this coating and so it is advisable to ask about the coating. If any part of the fence gets corroded it could cause rust stains on the area around it.
When choosing a chain-link fence consider how long you expect the fence to last, the wear and tear it will receive, and your budget to find the perfect solution for your fencing needs.