[Elecraft] RE: 'Refreshing' Aluminum

[Ferguson, Kevin]

Aluminum self passivates, forming an oxide layer that prevents
further corrosion.  Most aluminum _alloys_ don't share this feature.
Outside of electrical wiring, there are few applications for pure
aluminum....for almost every other application there is an alloy with
superior properties that doesn't cost much more....so it is rare to 
encounter pure aluminum in any structural application.

The most common aluminum tubing is 6061-T6 alloy.  This often comes with 
a thin protective layer of pure aluminum to prevent corrosion.  If you
cleaning
removes this layer, then you have lost the protection. THIS is probably what
happens with the steel wool.  Also, the fine scratching increases the
surface
area, increasing the rate of corrosion.

If you go to a large truck stop, you will find a bottle of "acid wash" for
restoring
shine to the aluminum steps, bumpers, etc. found on modern 18 wheelers.

Or you could just use vinegar.  Use it with a soft cloth, and elbow grease.
It 
will corrode any steel hardware, so you may need to disassemble prior to
cleaning.