Powder Coating On Zinga
Powder coating on Zinga treated surfaces is possible. Powders have been used over Zinga for over seven years now, and salt-spray testing has been under taken to 5000 hours with excellent results. These reveal that the steel is totally galvanised and finished in colour, with no potential for corrosion problems.
One of the main factors is that Zinga is not a paint, but a pure zinc coating. Due to this, Zinga can actually be applied in the same spray-booth or an adjacent spray-booth to the powder-booth. There is no danger regarding silicone poisoning or fish-eyes.
The Zinga layer can be reduced to as low as 40µm DFT underneath a powder-coat, as there is typically no more than 0.8% pin-holes in powder coatings. Where moisture or water-vapour can enter a microscopic pin-hole, once it penetrates through to the zinc layer it will react and plug the hole with oxides and carbonates.These are dense, non-conductive salts and even ionic currents cannot pass through to the solid zinc layer underneath.
Both gassing and non-gassing powders have been used over Zinga, although the non-gassing types do not always give a high-gloss finish.