Treat corrosion on aluminium
Aluminium window frames in homes are one area where aluminium corrosion often occurs for various reasons. While many are under the impression that aluminium rusts, since it does not contain any iron - aluminium does not rust but rather corrodes.
Aluminium window frames are installed in many homes in coastal regions, primarily for their resistance to weathering, but over time corrosion can occur and this appears in the form of dulling of the finish, calcium, lime or hardwater crusting or dust.
You may also find corrosion where aluminium frames are installed using steel clips, nults and bolts, or rivets, as reaction occurs (galvanic corrosion) between the steel and aluminium. Aluminum naturally has a smooth coating of oxidation and it is this coating that provides a hard shell barrier against corrosive elements. Strong acid and alkaline solutions dissolve the coating, which subsequently leads to corrosion.
Where corrosion occurs between joints, recesses and welding zones, on the edge of a join or crevice oxygen is reduced and aluminum will corrode. In these instances the treatment is best left to a reputable aluminium welding professional rather than trying to repair the problem yourself and end up with even more corrosion.
Treatment of unpainted aluminium alloy
1. Use a soft cloth to remove oil and surface dirt with any suitable mild cleaner such as dishwashing liquid. Do not use steel wool, steel wire brushes, or sandpaper.
2. Hand polish the corroded area with metal polish (Brasso is one such brand).
3. Rub over the polished surfaces with a soft cloth and wax polish.
Treatment of anodized aluminium
Anodized aluminium needs to be treated with care in order to avoid damaging the anodized coating in those areas not already corroded. Care must be exercised in the cleaning process to avoid unnecessary breaking of the adjacent protective film. Treatment is the same as for unpainted aluminium. When installing aluminium fittings or fixtures, ensure that the manufacturer provides you with information relating to the process used on the aluminium (anodized or not) and ask them for the correct procedure involved for cleaning and/or corrosion treatment.
Care and maintenance of aluminium fittings and fixtures
Aluminium is durable and resistant to water damage, but you should never use abrasive products of any kind as this will destroy the natural finish. Many glass cleaners can damage the anodized surface of the aluminum if allowed to remain on the surface for any length of time. Regular cleaning can be performed with a mild dishwashing detergent. After cleaning, wipe dry with a soft cloth.