Hi Rush,
If you are connecting copper to copper, you don't need to worry
about galvanic action on the joint. But if it is a clamped above
grade joint, you may want to use a silicone grease based compound
to prevent deterioration due to oxidation.
Subgrade connections should all be brazed or welded. If they are
to dissimilar material, then the connection should be
waterproofed before the dirt is replaced over the connection.
The above grade connections to the tower will definitely need to
take galvanic action into account. There was a large discussion
of this topic on the reflector within the last year or two.
You might want to search the archives for this discussion.
There are two things to watch out for when selecting the compound
to use.
1. Avoid the ones that have a petroleum based carrier.
2. Be careful what the filler metal (if any) is. If the
compound has metal filler particles, the metal used for the
filler depends heavily on the metal that is intended to be
clamped together. For example, it is not a good idea to use
compound with copper particles in it to join aluminum
components.
Clamping copper to galvanized steel should be done with an
intermediate layer of stainless steel.
73, Eric N7CL
To: <towertalk@contesting.com>
>Date: Fri, 22 Oct 1999 08:47:27 -0400
>From: Rush Johnson <W4QA@charlotte.infi.net>
>
>I am working on my ground system and am in the process of
>reconnecting copper straps and 4 guage copper wire to my ground
>rods, bulkhead, and 45G tower legs. I have been told that
>"joint compound" should be used (above and below ground) to
>prevent corrosion (and galvanic action?) from ruining the
>connections. I would appreciate any info on what the best way
>to use this is (i.e on the outside of the connections, "in" the
>connection, etc.) Also, is one type better than another?
>
>Thanks in advance.
>
>Regards,
>
>Rush -- W4QA
>
>--
>Rush Johnson -- W4QA (ex NR4M , WD4AEI)
>
>100 Horseman Cove
>Matthews, NC 28104-7760
>
>Tel: 704.814.0487
--
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