I am about to refurbish an old Hy-Gain TH3-Mk3 Thunderbird tri-band
yagi. This yagi has been used in a coastal environment and thus the
aluminum is slightly pitted and most of the connecting hardware needs
replacing.

I figure steel wool would work fine for the aluminum tubing, I know
how to test the traps, but I am wondering whether to use stainless
steel or galvanized hardware? Which would react least over time with
the aluminum? Also, I remember many years ago there is an electrical
joint compound stuff for using between the tubing sleeves - can anyone
please give me some brand names of this stuff?

Any other ideas appreciated....

Larry VE7EA

Larry,

I use "Ox-Gard", available from the local "Do-It Center" hardware store
outlet. Preserves overlap joints on aluminum tubing and makes them easy to
adjust and disassemble after years outdoors.

Works fine for radio waves, but does not conduct DC. Found this out the hard
way in an application where I was passing RF alongside some DC signaling
information. The RF got through just fine, the DC not so much.

-larry
K8UT
"lagagnon" wrote in message
...
I am about to refurbish an old Hy-Gain TH3-Mk3 Thunderbird tri-band
yagi. This yagi has been used in a coastal environment and thus the
aluminum is slightly pitted and most of the connecting hardware needs
replacing.

I figure steel wool would work fine for the aluminum tubing, I know
how to test the traps, but I am wondering whether to use stainless
steel or galvanized hardware? Which would react least over time with
the aluminum? Also, I remember many years ago there is an electrical
joint compound stuff for using between the tubing sleeves - can anyone
please give me some brand names of this stuff?

Any other ideas appreciated....

Larry VE7EA

I figure steel wool would work fine for the aluminum tubing,

I've read that it is *not* a good idea to use steel wool to clean up
aluminum, especially if it's going to be exposed to the weather.
There's a tendency for tiny bits of the steel to get caught in the
aluminum... it'll rust.

I'd suggest using a 3M (or generic equivalent) green abrasive
scrubbing pad. These pads are rough enough to remove oxidation from
copper PC board material, so I imagine they'll shine up aluminum just
as well, but they won't leave rustable material behind.

I know
how to test the traps, but I am wondering whether to use stainless
steel or galvanized hardware?

I believe that you can get some amount of electrolysis if galvanized
metal and aluminum are in contact, especially if the aluminum is not
well-anodized or if there is electrolyte around (e.g. if your area is
subject to salt spray). Some people in the boating trade claim "no
problem", others state that you should never use zinc-galvanized and
aluminum together.

Stainless-steel-and-aluminum seems to be the preferred combination.

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

Dave Platt wrote:
I figure steel wool would work fine for the aluminum tubing,

I've read that it is *not* a good idea to use steel wool to clean up
aluminum, especially if it's going to be exposed to the weather.
There's a tendency for tiny bits of the steel to get caught in the
aluminum... it'll rust.

I'd suggest using a 3M (or generic equivalent) green abrasive
scrubbing pad. These pads are rough enough to remove oxidation from
copper PC board material, so I imagine they'll shine up aluminum just
as well, but they won't leave rustable material behind.


3M pads and Bon Ami cleaner works well.

And clean aluminum has better gain. One of my 432 antennas tested at
Central States gained .4dB between very dirty oxidized elements and
cleaned elements.

tom
K0TAR

(Dave Platt) wrote in :

I figure steel wool would work fine for the aluminum tubing,

I've read that it is *not* a good idea to use steel wool to clean up
aluminum, especially if it's going to be exposed to the weather.
There's a tendency for tiny bits of the steel to get caught in the
aluminum... it'll rust.

I'd suggest using a 3M (or generic equivalent) green abrasive
scrubbing pad. These pads are rough enough to remove oxidation from
copper PC board material, so I imagine they'll shine up aluminum just
as well, but they won't leave rustable material behind.

Neverdull is far better to use.

http://www.nevrdull.com/

Bruce wrote:
(Dave Platt) wrote in :

I figure steel wool would work fine for the aluminum tubing,
I've read that it is *not* a good idea to use steel wool to clean up
aluminum, especially if it's going to be exposed to the weather.
There's a tendency for tiny bits of the steel to get caught in the
aluminum... it'll rust.

I'd suggest using a 3M (or generic equivalent) green abrasive
scrubbing pad. These pads are rough enough to remove oxidation from
copper PC board material, so I imagine they'll shine up aluminum just
as well, but they won't leave rustable material behind.

Neverdull is far better to use.

http://www.nevrdull.com/



Isn't the oxide good? Doesn't it protect the metal?

dave wrote in
:

Bruce wrote:
(Dave Platt) wrote in
:

I figure steel wool would work fine for the aluminum tubing,
I've read that it is *not* a good idea to use steel wool to clean up
aluminum, especially if it's going to be exposed to the weather.
There's a tendency for tiny bits of the steel to get caught in the
aluminum... it'll rust.

I'd suggest using a 3M (or generic equivalent) green abrasive
scrubbing pad. These pads are rough enough to remove oxidation from
copper PC board material, so I imagine they'll shine up aluminum
just as well, but they won't leave rustable material behind.

Neverdull is far better to use.

http://www.nevrdull.com/



Isn't the oxide good? Doesn't it protect the metal?


Yes, but it is non-conductive.

On Apr 28, 3:43*pm, lagagnon wrote:
I am about to refurbish an old Hy-Gain TH3-Mk3 Thunderbird tri-band
yagi. This yagi has been used in a coastal environment and thus the
aluminum is slightly pitted and most of the connecting hardware needs
replacing.

I figure steel wool would work fine for the aluminum tubing, I know
how to test the traps, but I am wondering whether to use stainless
steel or galvanized hardware? Which would react least over time with
the aluminum? Also, I remember many years ago there is an electrical
joint compound stuff for using between the tubing sleeves - can anyone
please give me some brand names of this stuff?

Any other ideas appreciated....

Larry VE7EA

I would stay away from the steel wool. Bits of it will imbed in the Al
and rust.

Jimmie

JIMMIE wrote in news:9b6a811c-4f7a-4686-a503-
:

....
I figure steel wool would work fine for the aluminum tubing, I know
how to test the traps, but I am wondering whether to use stainless

If you brush aluminium with a material, there is a tendency for the
material to become embedded in the surface.

Stainless steel is widely used to brush aluminium clean before welding, and
with minimum degradation. I would not use steel wool. Non metallic
scrubbers may embed non-conductive material in the surface, frustrating low
resistance connection between clamped surfaces.

I have found the little Dremel #530 stainless wheel brush handy for scratch
cleaning the inside of mating tubes, although limited in reach. I haven't
tried, but the flexible shaft adapter might give good reach into larger
diameter tubes. For the outside, I just use a stainless scratch brush.

Owen

Owen Duffy wrote in
:

JIMMIE wrote in news:9b6a811c-4f7a-4686-a503-
:

...
I figure steel wool would work fine for the aluminum tubing, I know
how to test the traps, but I am wondering whether to use stainless

....
Apologies, I mis-quoted there, the text was by lagagnon
.

Owen