Steel Fabrication: The Complete Guide to Powder Coating
29 June 2022
One common type of finishing used in steel fabrication is powder coating. Powder coating is a form of dry painting which differs dramatically from other processes like galvanisation or priming.
This guide will explain all you need to know, including a step-by-step explanation of how the process is completed and a run down on the benefits of choosing to powder coat your structural steel products.
What is Powder Coating?
Powder coating is a dry process of coating and sealing structural steel together as an alternative to paint. The necessary materials must be able to carry an electrostatic charge and resist high temperatures, hence why it’s often used on metal.
Choosing to powder coat is often a premium option when compared to painting, often coming at a higher cost. Still, despite this, it comes with many advantages, such as applying a very even coating, being more durable and resistant to corrosion, chemical damage and weather.
Powder coating is not flammable or carcinogenic and is much better for the environment than traditional paints.
How to Powder Coat Steel
The dry powder is applied to the surface electrostatically and then cured under UV heat or light. The powder is usually based on a polymer resin system which hardens through a curing process.
1. Clean the MetalÂ
The first part of the coating process is to clean down the steel thoroughly, including removing all dirt, grease or debris from the surface. Any extra particles could prohibit the electrostatic charge, rendering the powder application useless.
2. Pre-Treat the Metal
Next, the metal is pre-treated with a conditioner to set and lock in the pH level. Following that, the corrosion barrier is applied to protect from any damage, and a sealant is applied. The steel is then rinsed and left to dry in an oven before being left to cool completely.
3. Apply the Powder
The third step begins with earthing the metal and electrostatically charging the powder in preparation to be applied. The powder itself contains either epoxy or polyester resin, along with curing agents and a variety of additives to alter the colour and finish.Â
The powder is then sprayed onto the steel through a powder gun, which allows the powder to spread and sit evenly across the surface of the metal through an effect known as static cling.
4. Curing
The final step involves placing the metal into a curing oven where it is heated to around 200°C for 12-15 minutes. Curing allows the powder to turn into a hardened gel that binds permanently to the steel, creating a strong bond that forms a tough, durable finish.
Benefits of Powder Coating
While the powder coating process may seem convoluted compared to other finishes like traditional priming and painting, it creates a very strong and even-looking finish that provides many incredible benefits.
Learn more about the advantages of powder coating your steel:
Durable and Long-Lasting
Your powder-coated steel will be resistant to wear and tear no matter its use, whether it’s a steel beam (otherwise known as an I beam or universal beam), steel column, channel or steel tubing. A powder coat is also resistant to fading, chemical damage and weather, making it very suitable for use outside, whatever the conditions.Â
Powder coating also provides superior protection against corrosion, making it an excellent choice for use in high-moisture areas where steel could be prone to rust.
Saves Time and Money
Although the initial cost of powder coating can exceed priming and painting, in the long run, powder coating proves to be a much more cost-effective option. The steel sections will last significantly longer, especially if used in situations where its durability and longevity are put to good use.
The powder base used in the coating has a very long shelf life and results in minimal waste when the coating is applied to the steel, meaning fewer resources are needed, and more is recycled.
Environmentally-Friendly
As far as steel finishes are concerned, powder coating is a very environmentally friendly option. As previously mentioned, there is minimal waste when powder coating steel. Unlike paint, the powder base contains no volatile organic compounds (VOCs) to bind it because it simply uses its electrostatic charge to cling to the steel before being cemented in place through the curing process.
On top of this, the lack of VOCs present also means these structural steel beams are significantly better for the health of those working with the powder.VOCs carry a carcinogenic risk and can cause breathing problems through inhalation.
Order Steel from Local Steel Fabricators
Using our online web store is a great way to get in contact with a local structural steel fabricator and supplier wherever you are in the UK.Â
Try out our service to buy steel online, and you’ll be immediately connected to our UKCA-certified structural steel fabrication companies who can efficiently fulfil your order, with delivery and collection options available.