I just bought a very old, vertical antenna. The ant. is aluminium
andvery corroded.
Is this just a cosmetic problem, or will the corrosion affect the
radiation/reception of RF?
Since the insulation on wire antennas doesn't affect their
effectiveness, I'm thinking the corrosion wouldn't be a problem; but my
working-class logic has gotten me in trouble before. G Will painting
an aluminium antenna decrease it's effectiveness, or not
matter? Thanks

Bob -

If you wish to clean the aluminium - lye (NaOH) is often used -
however this
is a caustic agent - and usual precautions should be used if you use this
approach. There are also aluminium cleaners available at your local auto
supply stores.

Although some amateur use steel wool pads -- this can leave steel
slivers on
the aluminium tubing that can oxidize (rust) - I refer non metallic
scrubbing
pads if you need some elbow grease.

Hmm. Grey matter being a bit thin now, and about 40 years since I was at
school, but doesn't caustics on aluminium cause dangerous gases? Better
to use a scotch bright pad and an agent like Brasso (English name for
Brass cleaner compound) Once you've tin worm it's hard to stop the
oxydization. Your main priority is making sure the antenna has no
weaknesses in the wall thickness so that it's safe and will not bend.
Painting should have no detrimental electrical effects providing the
paint has no metalic compounds in it, but surly painting is just hiding
defects!! A previous posting asked about using stainless steel fixings
on aluminium, this causes an electrolitic conversion between the two
metals, not quite a good combination especially if you've shelled out
mega bucks for a decent antenna. After a few years in the air without
inspection you's be in for a big surprise.
Cheers from England. Dave

--
Amateur Radio Call Sign M1BTI, Located in Manchester England.
Locator square IO83TK
Chairman Of Trafford Radio Club. Club Call Signs G0TRG & M1BBP
Located at Umist, University Of Manchester Institute For Science And
Technology
Share What You Know, Learn What You Don't.

On Sat, 10 Sep 2005 19:02:39 +0100, Dave Piggin
wrote:

Once you've tin worm it's hard to stop the oxydization.

Hi Dave,

Is tin worm like White Pine Weevils or Bronze Birch Borers?

When a neighbor saw me laying out a ground field, he asked what I was
doing. I answered that I was doing root propagation to grow an
aluminum tree.

73's
Richard Clark, KB7QHC

Is tin worm like ... Bronze Bitch Borers?


I've met a few of them in my time...

Jim