Here's a bit of cross-disciplinary wisdom:
I ran across a brief note in the July 1997 edition of Sport Aviation, the
magazine sent to all Experimental Aircraft Association (EAA) members.
The note is from Paul Michel, who is apparently an employee of the FAA.
Paul quotes FAA Advisory Circular 43-4A: "Steel wool, steel wire brushes,
copper allow brushes or severe abrasive materials should not be used on
any aluminum surface. Aluminum wool, fiber bristle brushes and mild
abrasives are acceptable tools for cleaning anodized surfaces, but care
should be exersized in any cleaning process to avoid unnecessary breaking
of the protective film, particularly at the edges of the aluminum sheet."
He goes on to note that metal abrasives (such as steel wool) will embed
microscopic particles of material into the aluminum, and this will
subsequently cause deep pitting, due to dissimilar metal corrosion.
While I realise that not all aluminum is anodized, we would be best to
heed this warning even for ordinary aluminum tubing used in antennas.
Bill Coleman, AA4LR, PP-ASEL Mail: firstname.lastname@example.org
Quote: "Not in a thousand years will man ever fly!"
-- Wilbur Wright, 1901
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