Maintenance of anodized aluminium
The French Association for the Promotion of Anodized or Lacquered Aluminium (ADAL) informs about the minimum maintenance requirements for surface-treated aluminium.
The information comes courtesy of the ADAL website.
The anodizing layer consists of alumina (aluminum oxide) with a thickness of 10 to 20 microns. This layer has a high hardness protecting the aluminium and maintain a long durability of the appearance of the buildings using it. Its hardness allows it to withstand the action of a light abrasive. However, it is sensitive to acid (pH <5) and alkaline products (pH> 8).
It is therefore necessary to avoid cleaning with household products such as hydrochloric acid, caustic soda, vinegar and alkali.
The routine maintenance of the anodized joinery consists of a simple washing with water and a mild detergent (pH between 5 and 8) followed by a clean rinse with clear water and a wipe with a soft absorbing cloth. This operation can be combined with the cleaning of the windows.
In the case of slight fouling or deposits (limestones, marine salts), a slightly abrasive type F buffer may be used. During the cleaning operation, care must be taken to ensure that the drainage orifices are open. In the case of very heavy fouling (due to lack of maintenance) requiring renovation, it is recommended to contact a specialized company (for any information contact the ADAL).
Aluminium and its alloys used in the building and construction industry have, by themselves, a very good resistance to weather and even severe environments.
Anodizing provides effective extra protection.
To maintain the aesthetic qualities of the anodized aluminium, it is strongly recommended to carry out regular maintenance (see ADAL Information newsletter No. 19).
The frequency of cleaning depends on the environment and of the dirt thickness on the surface. The more frequent the cleaning, the easier and more economical it is.
Frequency of cleaning
In rural or urban areas where the atmosphere is not very aggressive, the maintenance frequency, for surface regurlary "cleaned" by rains is annually.
In urban, industrial or marine environments, surfaces exposed to rain require ideally a semi-annual maintenance.
Cleaning of areas not washed naturally by rainwater should be carried out more frequently than for exposed surfaces. In areas with high frequencies and high demands (building entrance, storefronts), cleaning can be carried out more frequently.
On surfaces regularly maintained, washing can be carried out with water added with a wetting agent (Teepol or similar). It should be supplemented with a clean rinse with clear water and a wipe with a soft absorbing cloth. This operation can be combined with the cleaning of the windows.
On medium-dirty surfaces, use "scrubbing-cleaning" cleaners specially developed for this use. These products contain a wetting agent and de-scrubbing materials. In any case, it is recommended to complete the cleaning by washing with clear water and wiping with a soft absorbent cloth.
On heavily fouled surfaces, if the fouling is particularly adherent, "scrubbing-polishing" products can be used such as synthetic Scotch-Brite F Finishing pads. A final, careful, clear water rinse followed by wiping with soft, absorbent rags is required.
With conservation treatment, the above methods can be supplemented by a preservation treatment using products which application leaves an ultra-thin and water-repellent film on the surfaces. The use of such products may, in some cases, combine the cleaning and preservation action. In all cases, however, this preservation film should not yellow, not attract dust, or cause an iridescent effect (especially on dark colored colored finishes).
It is essential to avoid the use of very aggressive products, such as certain detergents for dishwashers and laundry detergents as well as alkaline or acidic products. In addition, coarse abrasive pads such as steel wool or emery paper should be avoided.
If, in the vicinity of the building, construction work has caused dirt deposits on the aluminium surfaces (for example, work on the roadway in front of a shop or construction of a neighboring building), it is necessary on the parts not washed naturally by rain, to carry out a careful maintenance.
When cleaning products, it is strongly recommended to carry out a preliminary cleaning test on a small hidden surface using the instructions given in the technical data sheets of the suppliers of these cleaning products.