This is particularly true for exterior items prone to rusting and corroding in the harsh New Zealand environment. Both salt and high-UV sun can wreak havoc with coatings. Improperly treated steel, for instance, rusts very quickly and without proper pre-treatment will last only four months but correctly powder coated, will last approximately 20-30 years.
Metal must be prepared carefully and an anti-corrosive applied. This allows the powder to adhere properly, otherwise it simply falls off. How a product is pre-treated depends on what it is and what it will be used for. A complete pre-treatment process consists of cleaning, rinsing, conversion coating, seal rinsing, drying and cooling.
At Rainbow Powder Coaters, steel is pre-treated with iron phosphate. Aluminium undergoes a chromate conversion coating. Hot dipped galvanised items and electro-galvanised items are also sent through our chromate conversion tanks.