Re: [VAL] (no subject)...Clearcoat question

["Tom" <tmeeker@xxxxxxxxxxxxxxx>]

I've never seen clearcoat get cloudy over time when it is properly adhered
to the aluminum skin.  I have seen clearcoat begin to release from the
aluminum skin and the clearcoat in that area was cloudy as you say.  When
the clear coating is broken moisturized air gets underneath the applied
clearcoat and begins to lift if off the aluminum skin - which might or might
not cause the cloudy appearance.

I have clearcoat lifting off in places on our 1995 Airstream and this
peeling clearcoat is still clear to look through.  Automobiles that have
clearcoat which is allowed to develop cracks in the clearcoat due to neglect
also appear to be cloudy as you say.  It is no different in appearance on
automobiles or Airstreams when the clearcoating begins to deteriorate and
lift off the sheetmetal.

Also, not all aluminum skin is created equal.  The older Airstreams used
clad aluminum whereas the newer Airstreams didn't but rather used a newer
alloy instead.  You can actually see the difference in the aluminum skins
that have clad aluminum versus the skins that don't have it.

You can polish the clad aluminum skins to a mirror finish but remember you
are removing a finite amount of that clad aluminum in the process.  I have
no idea how many times you would need to polish the skins removing oxidation
before you'd actually begin to damage the underlying aluminum alloy of the
clad-coated aluminum skin.  I'm sure it can be done though.

It serves no purpose that I know of to even try to attempt a mirror shine on
the newer alloy aluminum sheetmetal.  The two metals would never look the
same - only clad aluminum will give the mirror finish.

The darker aluminum skin used by Airstream does not have the 100% aluminum
cladding like the older Airstreams, which is why it is darker in appearance.
I do not know what year or years are involved when Airstream began switching
over from the clad aluminum to the unclad aluminum alloy of today.  I'm sure
that the clearcoats have also changed chemically over the years - but on
second thought maybe I won't bet on that either.

Tom
WBCCI 5303