[VAC] Re: Mirror shine/old aluminum

[RJ Dial <rj.dial@xxxxxxx>]

Here's what my notes show:
From 1948 the external skins were 2024ST aircraft aluminum alloy with an alclad layer 
(a soft thin pure aluminum protection layer) until the late 60's when the alclad layer 
was dropped   (no exact dates, as old stock and formed pieces were used up at varying 
rates.

Alclad was dropped because Clearcoat became an option in 1962 and standard in '65 to '66, 
depending on the model.

In the mid '82 model year trailers were changed over to the etched panels (dull matte 
finish).

In Aug 1998 ('99 model year) the etched skins went prefinished, much like  modern 
prefinished hardwood floors.

Charlie Burke can probably verify if the above is correct and fill in a few blanks.

It is the alclad layer (with no alloy elements) that give the early trailers their 
brighter polish, but is also why care must be taken not to sand or etch the alclad layer 
(.002"-.005" thick) - otherwise there is a slightly noticeable change in those spots.   
Our '65 Caravel had a few spots like that from when someone stripped and sanded off the 
clearcoat back in the early '80's. You can see them close-up, but aren't too noticeable 
from afar.

RJ
'65 Caravel
(www.vintageairstream.com)