[ARC5] Taigh Ramey - please contact me - AL cleaning.

[Mike Hanz]

It is a function of the type of aluminum, Ken..  For example, the B-29s 
used a variety of aluminum alloys, but the parts of the skin that really 
shine is made of Alclad, a variation that has a thin layer of pure 
aluminum on the surface.  The high stress components are of a different 
alloy (7075) and it doesn't polish worth a darn.  You can see that 
difference in the aerial shots at 
http://aafradio.org/NASM/Enola_index.html .  Acid rain can eat through 
sections of the pure aluminum layer, unfortunately.

In terms of aluminum polish, I like Met-all, but there are a bunch of 
them out there.  I think we used close to half dozen different types 
polishing the Alclad on the Enola Gay - none of them stood out over the 
others, as I recall.  With somewhat corroded metal, there is a tedious 
method of polishing aluminum that I have used a number of times in the 
past, but it demands infinite patience.  Nothing magic about it - you 
just start with 220 grit wet or dry paper and keep shifting to finer 
paper until you have it down to a level that met-all or similar polish 
can work effectively.  Of course, most of the aircraft radio chassis and 
the like then have to have an aluminum etch that will reduce the 
recently polished aluminum to a nice white matte finish.  Somewhat of an 
anticlimax, but that's the process.  :-(    If you have corrosion 
products you might start with the etch and then go through the polishing 
evolution, but there is nothing I'm aware of that is a miracle solution.

 - Mike

Kenneth G. Gordon wrote:

>I thought I would ask Taigh about this, PLUS ask the collective wisdom 
>while I was at it.
>
>Every time I see another photo of a restored warbird, whoever has done 
>the work has polished the aluminum until it looks like a mirror.
>
>I have tried any number of methods to obtain the same effect and, so 
>far, have failed. Not only failed, but failed miserably.
>
>In fact, I STILL have not come up with a relatively simple method to 
>even CLEAN the aluminum acceptably.
>
>Nothing I have used so far has done even a fair job of cleaning all the 
>surface garbage off aluminum, let alone making it shine.
>
>So, I guess I have TWO different questions here: 1) how do YOU 
>thoroughly and effectively CLEAN aluminum, I.e. BC-458s, and 2) how 
>do YOU give aluminum that beautiful mirror shine?
>
>Any help would be very much appreciated.
>
>Ken Gordon W7EKB
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