What is Hot Dipped Galvanising?

Galvanising steel is a chemical process that is used to create a protective coating in order to prevent corrosion of steel through atmospheric exposure.

So called “hot dipped” galvanising involves a process where the steel is literally dipped into a bath of molten zinc to create the protective layer.

The hot-dipped galvanising process

Many of our clients would be familiar with our galvanised reinforcing steel products, but how exactly does steel become galvanised in the first place?

Step 1: Cleaning the steel

Firstly, the steel is thoroughly cleaned by immersing it in a highly caustic solution in order to remove any surface impurities like oil, dirt or paint, which could disrupt the galvanising process later on.

Step 2: Pickling the steel

Next, the steel is “pickled” in an acidic solution to remove mill scale to ensure that the steel surface is completely clean and free from debris.

Step 3: Hot dipped galvanising

Now that the steel surface is fully prepared, it is dipped into the bath of molten zinc.

The steel will remain in the bath until it reaches the same temperature as the zinc bath itself (around 449 degrees celsius). This ensures that the chemical reaction is thoroughly complete.

Step 4: Cooling

The final step is to cool the steel in a “quench tank” rather than simply letting it air cool.

This is done to ensure that the atmosphere doesn’t prematurely begin to interact with the galvanised surface before it has properly cooled.

Hot dipped galvanising is considered a superior method compared to cold galvanising (sometimes called cold plating) because it ensures that the steel is thoroughly coated and the galvanising layer is extremely durable.

Since galvanised steel is typically used in outdoor applications where the prevention of corrosion can be assured, hot dipped galvanised steel is the usual choice. 

Neumann Steel – Your Steel Mesh Experts

For more details, contact our expert team. Choose Neumann Steel for high-quality steel mesh and reinforcing mesh. We’re not just suppliers; we’re your partners in building durable and reliable structures. For enquiries or quotes tailored to your project’s needs, our expert team at Neumann Steel is here to assist you. For a technical or design discussion, submit an enquiry via our contact page.