>Furthermore, two years down the road and you need to do it all again!
 

Hi Tom and all; actually that is true for a polish only. There is a
chemical coating used in the aircraft industry in the alodine family
that forms a protective shell on aluminum that is essentially
permanent, and does not require a repolish job every two years. Only
normal washing will keep this finish clean. There are two flavors of
this stuff, one is clear, and the other gives a nice golden color
which would probably look great on an Airstream, except that
Airstreamers would doubtless not appreciate a gold bullet, as opposed
to a silver one !
 

Doug