What Is Galvanizing?
Galvanizing is the practice of immersing clean, oxide-free steel into molten zinc to form a protective coating over the metal. The coating is bonded metallurgically to the steel and this coating helps to protect the surface against corrosion
How Long Does Galvanizing Last For?
This depends on the corrosion rate of the environment that the work is in and the thickness of the galvanized coating. Since atmospheric corrosion rates in the UK have fallen significantly over the last few decades, the general level of protection offered by a galvanized coating has in many cases, more than doubled. With typical corrosion rates averaging 1-2 microns per year, a coating life in excess of 30 years would not be uncommon.
If the coating is scratched and scuffed, will it last as long?
Hot dip galvanized coatings have excellent abrasion resistance. In fact, the outer zinc layer is soft enough to absorb impact and abrasion while the alloy layers that are metallurgically bonded to the steel, are harder than the steel substrate. Minor abrasion will have little impact on the life of the coating.
If I have to do any repairs or alterations on site, can the galvanizing be repaired?
The most common method for repairing galvanized coatings is to use a suitable zinc rich paint. This needs to be applied in accordance with the manufacturer’s instructions and to a thickness equal to or 30µm more than the surrounding coating depending on whether or not the item is to be over coated. An alternative method is to have the area zinc thermal sprayed to the required thickness.
What is powder coating?

Powder coatings are based on polymer resin systems, combined with curatives, pigments, leveling agents, flow modifiers, and other additives. These ingredients are melt mixed, cooled, and ground into a uniform powder similar to baking flour. A process called electrostatic spray deposition (ESD) is typically used to achieve the application of the powder coating to a metal substrate. This application method uses a spray gun, which applies an electrostatic charge to the powder particles, which are then attracted to the grounded part. After application of the powder coating, the parts enter a curing oven where, with the addition of heat, the coating chemically reacts to produce long molecular chains, resulting in high cross-link density. These molecular chains are very resistant to breakdown. This type of application is the most common method of applying powders. Powder coatings can also be applied to non-metallic substrates such as plastics and medium density fiberboard (MDF).

Sometimes a powder coating is applied during a fluidized bed application. Preheated parts are dipped in a hopper of fluidizing powder and the coating melts, and flows out on the part. Post cure may be needed depending on the mass and temperature of the part and the type of powder used. No matter which application process is utilized, powder coatings are easy to use, environmentally friendly, cost effective, and tough.

How long does powder coating last?

This is a very common question. There are many aspects to consider when determining the longevity of powder coatings including the nature of the application and the surrounding environment. Salt, pollution and general deposits will effect the lifespan of the product and it is suggested that you follow a maintenance program to assist the longevity of the coating. Click here for more information on how best to maintain your powder coating.

From the perspective of adhesion and film integrity, with experience like PCS has, correctly applied and pre-treated powder coated metal can and has lasted since it was first applied more than 40 years ago.

Powder coatings are considered extremely resilient, and are a coating of choice for use on gas or oil pipelines which are buried in the earth or underwater. Powder coatings are also commonly used on automotive parts and commercial and residential appliances because of their excellent chip resistance, hardness and or chemical resistance.

From the perspective of resistance to light and UV degradation, some powder coatings are outstanding, being used on the facades and window sections of large buildings.

The standard range of powder coatings are designed for general outdoor use and applications. They offer good weathering resistance, excellent film integrity and very good hardness

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Farrer Mill Yard
Farrer Mill Lane
Halifax, West Yorkshire

Tel. 01422 349536
Fax. 01422 349468