Thanks for your quick replies, which ranged from ...
,,, I've rebuilt antennas that were VERY corroded by using 600 grit sand paper to
polish off all the crud, blew the dust off with dry compressed air, then wiped them down with denatured alcohol, gave them a good coat of self-etching primer, and after waiting a few days for the primer to fully set up, painted them with one-part epoxy paint. I've never seen ANY evidence of detuning from this process, and some of the antennas I did 5 years ago still look like the day I finished them.
,,, I was just told that the phosphoric acid in LocTite's "Aluminum Jelly" works
well, too.
... I was recommending the cleaning of the elements, then a liberal dousing of
marine spar varnish for protection. But after years of recommending that, I had one person tell me that it wasn't good for him ...
Clint