This is from the official Elsa Win CD's
Problem description
Mat aluminium trim strip discoloured, milky
Cause
The silver-coloured trim strips of the Audi models consist of pure aluminium (AL 99.9).
The use of aluminium on the vehicle is in line with the Audi philosophy and helps to protect the environment, since during the production of conventional chrome trim strips an exceptionally high number of pollutants and toxins are released.
Unlike chromed trim strips the disposal of trim strips of pure aluminium is relatively easy.
During their production aluminium strips are highly polished. Then an protective coat is applied by anodal oxidisation.
This anti-corrosion coat is between 8 - 10 micrometer thick and transparent.
It is relatively brittle similar to a ceramic coat. This means, fine hairline cracks are created on the strip if it is bent, thus damaging the protective coat.
No polish or alkalic/acid cleaning agents must be used, as they can damage the aluminium coat. Please observe the processing instructions of the cleaning agents you use (for instance industrial dust remover).
In car washes alkalic intensive cleaners are used.
As these cleaners are highly concentrated, they must be sufficiently thinned down with water. Make sure that remnants of the cleaner on the vehicle are completely rinsed off. This is especially important on hot summer days, as the water dries relatively quickly and remnants of the cleaner cling to the vehicle surface, which can cause damage.
If the protective coat is damaged, this leads to white corrosion on the aluminium (the trip steams up, becomes mat or milky, see attachment).
[IMG]file:///C:/ElsaWin/docs/hs2/A/en-GB/viewer/hst2-html-view-2003-10/res/hinweis.gif[/IMG]
•Please observe the information in the owner's manual about the care of aluminium strips.
Production solution
No change.
Service solution
Replace damaged trim strips. Explain the background to the customer.
Accounting instructions
This is no fault in the sense of warranty.
