PRETREATMENT OF ALUMINIUM BEFORE POWDER COATING.

The use of powder coatings as protective and decorative finishes for aluminium has increased rapidly in recent years. Common uses include window and patio door frames, garden furniture, structural components of buses, domestic appliances and engineering components. This increasing and wide use of the finishing technique has endorsed the need for an effective pretreatment of the surface to ensure that the excellent protective properties of the coatings are maintained for many years. The sequence recommended for best performance where chromate coatings are used consists of non-etch alkali cleaning, alkaline etching, rinsing, conversion coating, rinsing and de-ionised water rinsing.