Soft Anodising

The most common form of anodising is sulphuric acid anodising which offers an anodic film thickness between 3 and 25microns, depending on the end use of the components. The lower to middle ranges are ideal for decorative finishes which may be dyed, etched and/or brightened to enhance the component's appearance. Anodic film thicknesses above 15microns are used for increased durability and external applications, where corrosion resistance and wear are the main criteria.

Depending on which alloy it gives a uniform appearance silver to grey, which can be dyed a wide range of colours.

Good for protection where a cosmetic appearance is required, can be dyed in a range of colours. The sulphuric acid anodizing process is capable of yielding a range of coating thicknesses on most aluminium alloys. It is suitable for general protective purposes and for the production of a suitable surface for subsequent painting or adhesive bonding.

The process shall be specified where anodising is required on aluminium alloy items which are liable to be used in contact with concentrated hydrogen peroxide.