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What Is Hot Dip Galvanising?

WHAT IS HOT DIP GALVANISING
& WHAT ARE THE BENEFITS?

At Savannah Campers & Trailers we build high quality hot dip galvanised trailers. We have exclusively used hot dip galvanised steel for our entire range of single axle and double axle trailers. Why do we do this? We thought it might be worth putting together this little piece to explain exactly what it is and why it is the superior finish for trailers.

The Process

Hot dip galvanising is the process of coating metal in molten zinc. This process can be broken down into three main steps; surface preparation, galvanising and inspection. All three need to be completed thoroughly so that the surface will last in all weather conditions. To see a visual breakdown of the overall process take a peek at this video put together by the American Galvanisers Association (https://www.youtube.com/watch?v=UE7zY9JoVIc).

Surface Preparation

When the material arrives at a galvanising facility it is hung by wire. Here it is placed in a racking system which can be lifted and moved through the process by cranes. The steel then goes through a series of three cleaning steps; degreasing, pickling, and fluxing. Degreasing removes dirt, oil, and organic residues. The acidic pickling bath will remove mill scale and iron oxide. The final surface preparation step, fluxing, removes any remaining oxides while coating the metal with a protective layer to prevent any further oxide formation prior to galvanising. Proper surface preparation is critical, zinc will not react with unclean materials.

Galvanising

After surface preparation, the steel is dipped in the molten bath of at least 98% zinc. The steel is lowered into the kettle at an angle that allows air to escape from tubular shapes or other pockets, and the zinc to flow into, over, and through the entire piece. While immersed in the kettle the zinc metallurgically reacts with the trailer parts to form a series of zinc-iron inter-metallic layers and an outer layer of pure zinc.

Inspection

The final step is an inspection of the coating. A very accurate determination of the quality of the coating can be achieved by a visual inspection, as zinc does not react with unclean steel, which would leave an uncoated area on the part. Additionally, a magnetic thickness gauge is used to verify the coating thickness complies with specification requirements.

This is just a quick overview of the complicated process of galvanisation. Hot-Dip Galvanising is designed to protect your trailer from rust and wear. By using this method, we increase the life expectancy of all our trailers by up to 20 years. This is also very important for coastal areas as trailers are more susceptible to rust in these areas.

Why Not Paint?

This is a pretty cut and dry answer. Hot dip galvanising is better. It is going to last long into the future and protect your trailer. Although paint can be aesthetically pleasing it is easily damaged by the weather as well as wear and tear. We want our trailers to last well into the future. A good quality painted trailer may last a few years with absolutely no trouble. But if you look at a 10-year-old painted trailer in comparison with a 10-year-old hot dipped trailer you will easily see the difference. We want our trailers to last a lifetime, not only a few years. We believe if you are going to invest your hard-earned money into a trailer you should get a good return on your investment through the years you can use it. That’s why we hot dip galvanise.

If you are on the lookout for a quality trailer that will last long in to the future make sure to check out our full range of hot dip galvanised trailers at our showroom 15 Hargreaves St Edmonton.