An excellent source of information on Aluminium Corrosion is Aluminium Matter . This is an e-learning website which seems to cover most of the corrosion issues airstreamers will be faced with.
While keeping the outer skin in good condition is one concern, you should not forget about the inner skin.
Exhibit 1 - CA built Airstream, 1956
Alclad supplier - Reynolds
Location - Primarily resided in California
NB - The content of these images may be disturbing or offensive to some aluminitus sufferers. While they may look bad, I would like to mention it's all treatable, it just takes time -
Outer skin, tell tail signs -
Inner skin, the full extent of corrosion is revealed -
Closer look and a slight tap -
Factory sealing of the seams has not help stop the corrosion -
Rear light panel will need replaced also -
Other Isolated patches -