Anodising is the procedure by which the natural film on aluminium is very much increased in thickness. The metal is on the anodic side of the galvanic series. Its position is alike to zinc and magnesium, i.e. it is readily oxidised. This oxide on aluminium is physically corrosion resistant, abrasion resistant, very hard, an insulator and very tenacious. In its natural form the oxide film is less than 0.50 microns thick.

Since the naturally occurring film is so thin and attached to a soft supple metal, it is easily damaged. So building up this coating will provide very useful properties for the aluminium anodising on Dallas.

Preparation

The very basis of every excellent coating is preparation. In anodising, good preparation is necessary. Oils and greases are removed in weak alkali solutions and the exterior is etched to remove heavy oxides. After rinsing, the aluminium metal is dipped into a desmut solution so as to remove the insoluble components of the aluminium which remains on the outer surface after etching, rinsed and presented for anodising.