This is probably the most common question we get. If you had to give a short answer, I would say that galvanization is always the winner. But that’s not a full answer, so let explain.

What is galvanization?

For hot dip galvanization, the steel goes through a bath with molten zinc, which is at a high temperature. This isn’t a coating, a chemist would say a bond is made, as the zinc becomes a part of the steel. If you lived the mountainous countryside, and you did this with a gate, you probably wouldn’t have to deal with it for a while. But if you’re in a more populated urban area, you have to deal with it at a more frequent rate.

Another item to add in the galvanization win column is when it chips, the zinc will slowly oxidize, and because of this the steel is protected.

However, there is a more positive tub of powder coating. Powder coating comes in different colors and provides a consistent and smooth surface.

A good powder coating can last outdoors from 10 to 15 years. Unfortunately, powder coating that shows signs of chalking, fading, or chipping represents a prematurely aged coating. Chipping leads to the coating malfunctioning to a greater degree. Through chipping, the substrate can come into contact with moisture and begin to rust, creating a rust blister. Underneath the coating, the rust blister will scatter the coating further, causing even greater damage. By the time the coating damage becomes evident, rust will be present throughout.

Many people wonder if the coating can be repaired. Rust can be stamped out, but the substrate will need to be prepared, in the form of stripping it to its base coating. The substrate can be further refined to a rust grading scale of 1.0 (0.0 being no rust, and 1.0 being heavily rusted).

For more metal work with a longer life span, and powder coating, the best option is to start with a layer of zinc galvanization (because of its superior rust resistance) and with a newer powder coating on top. This mitigates the powder coating chipping to rust spalling. Rust spalling becomes a problem if powder coating overlaps a zinc galvanization.

This is why we recommend this powder coating for commercial gates and external railings, because of a need to eliminate spalling rust with a long-life span. This is the best option for outdoor metals with a long life span, because this option has a higher upfront cost than powder coating alone.

South Yorkshire context

Anything built near a road, or especially near a highway, should consider road salt, since the night gritting winter splashes are hard on finishes. Galvanising can withstand the issues of using a powder coat alone. For applications near major roads or where traffic runs right up the gates, you should take that into consideration when speccing your properties.

If you are removing existing metalwork that has old powder coats where rust has tracked from underneath, that explains why. That rust won’t happen on a properly galvanised piece of new work for a very long time.

Any particular finish option queries for a job, just contact us, and we will let you know what we think is best.