Our Dura-coat™ finish is a multistage process in two main parts, galvanizing and powder coating.
Hot dipped galvanizing is the process of coating steel by immersing the metal in a bath of molten zinc, at very high temperatures. A coating is formed, giving the steel a robust, durable, and corrosion protective finish.
Powder coating is the topcoat. The process of coating the surface with a powder material, heated to its melting point, which then flows and cures to form a smooth, firm, durable finish. Very resistant to scratches, cracking, peeling, UV rays and rust.
The secret to a good quality coating lies in the preparation of the surface. This is achieved by taking the steel through a number of pre-treatment stages.
Degreasing is first carried out using either acid or alkaline-based chemicals. Pickling is carried out in diluted hydrochloric acid, which produces a chemically clean surface, which will react with the molten zinc.
A mixture of zinc chloride and ammonium chloride are then used before the steelwork is thoroughly dried. We then immerse the steelwork in a special bath, holding malt and zinc at 450°C. While it is submerged, it alloys with the iron in the steel, to form zinc iron alloy layers. These layers form the basis of the coating, which is then overlaying with zinc as it is withdrawn from the bath.
The end result is a coating that not only has great abrasion resistance, but one that can last up to a 170 years.
During fettling, we carefully remove any uneven, hardened galvanizing drips to provide a quality finish to the surface of the final product. More degreasing, cleaning, rinsing and drying now follows before the powdered coating is applied.
Powder coatings are based on polymer resin systems, combined with curatives, pigments, levelling agents, flow modifiers and other additives. These ingredients are mixed and ground into a uniformed powder, a bit like flour. We use a spray gun which applies an electrostatic charge to the powder particles, which are then attracted to the steel.
After a part is sprayed, it is transferred to a large oven, where the powder melts and flows into a smooth coating. Our Dura-coat™ finish provides a more durable finish than liquid paints can offer. Products are more resistant to scratches, chipping, abrasions, corrosion, fading and other wear issues. It’s tough, it looks great, and it lasts a long, long time.