The technique of Priming uses a paint rich in zinc phosphate, which is applied to the steel, and which provides an active corrosion resistant coat. The compound in the paint disrupts the normal formation of anodes on the surface of the steel, what we would generally see as ‘rust’. It achieves this by hydrolysing in water to produce zinc ions (Zn²⁺) and phosphate ions (PO₄^3-). The phosphate ions act as anodic inhibitors by phosphating the steel and rendering it passive, whereas the zinc ions act as cathodic inhibitors. To be sure this method will protect your steel, the paint needs to be applied at an optimum thickness of 125 microns. For this, two layers need to be applied directly on the steel using a roller, after which the steel should remain rust resistant as long as it is not used outside in harsh conditions.