On Mon, 12 Mar 2007 11:05:13 -0700, Hank Zoeller
wrote:

Richard Clark wrote:
Wire brush mating connections and assemble quickly - forget the rest.

Interesting.

I understand the reason for quick assembly but I'm curious about the clean-up of
the oxidised aluminum elements. What kind of wire brush? Steel? Brass?
Why not some sort of abrasive paper? Or a Scotch Brite pad?

Hi Hank,

I was speaking more to the idea of cleaning what is ultimately a
cosmetic issue - the rest of the elements. Forget that.

As for your choices in abrasive materials, use what comes to hand. By
this time many would have chimed in with their favorites, and
compounded with lengthy technical reasons. Those reasons are usually
all very well and good in the face of neglecting other simple
considerations which I will expand on.

I'm also curious why you seem to dismiss the use of conductive anti-sieze
compounds - Penetrox, for example.

This is a kind of belts-and-suspenders solution. There is nothing
wrong with it, but you don't have to go out of your way to use this
stuff if you are mating similar metals.

BTW, I'm not trying to be argumentative,

What a buzz-kill!

I'm truly curious about your thinking
on the matter. Last fall, I put up an aluminum tubing vertical and I'm looking
forward to taking it down this spring to see how it fared over the winter.
Prior to reassembly I planned on cleaning up the mating connections with
aluminum oxide paper and using a light coating (wipe on, wipe off, thin film
left behind) of Penetrox.

Let us know how that fared. Myself, I lay down a layer of tape
(Scotch 3M rubber) that extends above and below the joint. I then add
a layer of clay (the black stuff you can buy for more money to pay for
the trademark) typically found either in a flower shop or at the
plumbing shop. I then wrap that with another layer of tape. The two
layers of tap encapsulate the clay for easy, clean removal only.
Joints are always bright and dry when disassembled and we get enough
wet here in Rain City to test that claim. My lawn is now buried in 3
inches of moss. I wish I could kill the grass completely.

I don't suppose many would go to this level of waterproofing of yagi
elements (I don't have that luxury to consider at the HF end of the
scale, and the VHF/UHF never seem to have any problem with connections
that are manufactured to be tight). I do this level of waterproofing
with every connector or connection, however.

73's
Richard Clark, KB7QHC