The Anodising Process What is anodising? Anodising is an electro-chemical process used to create a protective film of aluminium oxide on the surface of aluminium profiles or sheet aluminium. As the aluminium oxide film is created from the aluminium itself, it is integral to the aluminium and cannot crack or peel. Anodising finishes Pre-treatment of the aluminium surface before anodising can produce variations in the final appearance of the anodised product. Common finishes are satin or linished (brushed). Anodising colours A wide range of anodised colours can be obtained through a process known as electrocolouring. When colour anodising is specified, the colour is generated with the use of metal salts during the completion of the anodising process. For permanency of colour, no dyes or pigments are used. Anodising hardness The aluminium oxide surface is the same material as sapphire or carbordundum, and provides a hard, wear-resistant and weather-resistant surface for architectural aluminium products. Corrosion resistance Anodised coating thickness can be varied from 10 microns to 25 microns to give the desired level of corrosion resistance and wear resistance. For recommendations, click here. Cleaning recommendations To maintain the decorative and protective properties of anodising against atmospheric pollutants and grime, a regular cleaning schedule should be specified and adhered to. The preferred method of cleaning anodised aluminium is with warm soapy water, gently rubbing with a damp cloth or sponge until any grime is removed. It is important to rinse thoroughly with fresh water to remove any traces of soap or detergent. Acid or alkaline cleaning compounds should be avoided as they may attack the anodic surface. Abrasive cleaners should not be used.
Recommended Anodising Thickness & Cleaning Frequency Interior Applications Exterior Applications Conditions Thickness Frequency Conditions Thickness Frequency Mild 10 microns 12 months Mild 15 microns 12 months Moderate 15-20 microns 12 months Moderate 15-20 microns 9 months Severe 25 microns 6 months Severe 25 microns 9 months Very Severe 25 microns 3 months Very Severe 25 microns 1-3 months Severe or very severe interior conditions could result from moisture condensation, such as in indoor pools. Severe or very severe exterior conditions could result from a coastal site exposed to salt water vapour. Warnings Contact with highly abrasive materials such as sandpaper and steel wool should be avoided. Contact with alkaline products such as the mortar used in cement rendering, plastering and tiling must be avoided totally and any traces should be removed from any anodised surface immediately.