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Old November 21st 04, 04:29 PM
Jim Keller
 
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Default Corrosive protection for ground radial plate?

I have an HF9V vertical that uses about 36 radials. The radials are
terminated at a square aluminum plate at the base of the antenna. I
have about a dozen holes in the plate. The screws, washers and nuts
to secure the ground wires to the plate are stainless steel. The
lugs at the end of the ground wire are the type intended for house
wiring. Maybe zinc coated over copper?

I would like to disassemble everything, clean it all up, then
reassemble but this time using some type of protective coating on each
connection to prevent moisture from getting in and disturbing
conductivity to all connections to the plate.

Question is, what have others done to prevent antenna connections,
such as ground radials from corrosion at their points of contact?

I've heard about Penetrox and was curious if it would work in this
application.

I live about 5 miles from the Ocean and the vertical is located on a
slope that gets watered at least once a week.


Thanks,

Jim Keller
WB6YXY
Oceanside, Ca.
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Old November 21st 04, 11:43 PM
Ian White, G3SEK
 
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Default

Jim Keller wrote:

Question is, what have others done to prevent antenna connections, such
as ground radials from corrosion at their points of contact?

With copper wires soldered to a copper pipe busbar, I used several coats
of clear polyurethane spray lacquer. Five years later, it looks like
new.

Anything that will keep the water out of the joint between the two
different metals will do fine. The advantage of clear lacquer is that
you can see what condition it's in without disturbing anything.


I live about 5 miles from the Ocean and the vertical is located on a
slope that gets watered at least once a week.

I live in England. The whole country gets watered, several times a week.


--
73 from Ian G3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek
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Old November 22nd 04, 10:59 PM
Bob McConnell
 
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Default

On Sun, 21 Nov 2004 23:43:39 +0000, "Ian White, G3SEK"
wrote:

Jim Keller wrote:

Question is, what have others done to prevent antenna connections, such
as ground radials from corrosion at their points of contact?

With copper wires soldered to a copper pipe busbar, I used several coats
of clear polyurethane spray lacquer. Five years later, it looks like
new.

Anything that will keep the water out of the joint between the two
different metals will do fine. The advantage of clear lacquer is that
you can see what condition it's in without disturbing anything.


I live about 5 miles from the Ocean and the vertical is located on a
slope that gets watered at least once a week.

I live in England. The whole country gets watered, several times a week.


Hi Jim,

The major corrosion problems occur when you mate dissimilar metals.
Copper to aluminum is probably the worst in my experience. Here in the
states, we mixed copper and aluminum wiring in houses for a while in
the 60's and 70's, before AL wire was completely outlawed. There were
two fixes developed to control the corrosion. One was a special alloy
for all fittings, screws, clamps, etc. that might came in contact with
either or both metals. I still see electrical hardware marked CU/AL to
indicate it is made from that alloy. Then a paste was developed that
would prevent the oxidation from occuring. All points where both
metals came together were coated with it, before and after assembly.

There are other combinations, some of which have galvanic properties.
There are anti-seize and other pastes to deal with some of those.
Sometimes, all you need is a good silicon based lube, liberally
applied and wrapped with shrink wrap and electrical tape to keep the
rain out.

Bob McConnell
N2SPP

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Old November 23rd 04, 12:32 AM
Jack Painter
 
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Default


"Bob McConnell" wrote
The major corrosion problems occur when you mate dissimilar metals.
Copper to aluminum is probably the worst in my experience. Here in the
states, we mixed copper and aluminum wiring in houses for a while in
the 60's and 70's, before AL wire was completely outlawed. There were
two fixes developed to control the corrosion. One was a special alloy
for all fittings, screws, clamps, etc. that might came in contact with
either or both metals. I still see electrical hardware marked CU/AL to
indicate it is made from that alloy. Then a paste was developed that
would prevent the oxidation from occuring. All points where both
metals came together were coated with it, before and after assembly.

There are other combinations, some of which have galvanic properties.
There are anti-seize and other pastes to deal with some of those.
Sometimes, all you need is a good silicon based lube, liberally
applied and wrapped with shrink wrap and electrical tape to keep the
rain out.

Bob McConnell
N2SPP


Hi Bob, a caution to anyone using silicone for any part of a grounding or
bonding connection: silicone is a dialectric, and is not appropriate for
anything other than an outer component of waterproofing - which I gather you
meant but might have confused some folks. The copper pastes (or alloy
mixtures) which you mentioned are the appropriate internal and external
coatings for electrical connections in lightning protection systems - which
any ground radial system is also providing. These are available at most
electrical supply companies.

73,
Jack Painter
Virginia Beach VA


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Old November 25th 04, 08:27 AM
Roger
 
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Default

On Mon, 22 Nov 2004 22:59:20 GMT, Bob McConnell
wrote:

On Sun, 21 Nov 2004 23:43:39 +0000, "Ian White, G3SEK"
wrote:

Jim Keller wrote:

Question is, what have others done to prevent antenna connections, such
as ground radials from corrosion at their points of contact?

With copper wires soldered to a copper pipe busbar, I used several coats
of clear polyurethane spray lacquer. Five years later, it looks like
new.

Anything that will keep the water out of the joint between the two
different metals will do fine. The advantage of clear lacquer is that
you can see what condition it's in without disturbing anything.


I live about 5 miles from the Ocean and the vertical is located on a
slope that gets watered at least once a week.

I live in England. The whole country gets watered, several times a week.


I live in Michigan. We get watered every day for a month and then
nothing for a month.
:-))

Hi Jim,

The major corrosion problems occur when you mate dissimilar metals.
Copper to aluminum is probably the worst in my experience. Here in the
states, we mixed copper and aluminum wiring in houses for a while in
the 60's and 70's, before AL wire was completely outlawed. There were


Completely outlawed? It's tripple ought AL right into my breaker box
and that was installed last year. OTOH I've never seen outlet wiring
made of AL.


snip

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com
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