Aside from "Kitty Litter", oil absorbent for sweeping mechanic's floors
clean, and other domestic uses, sodium bentonite is the major ingredient in
oil well "mud." It is used also as a sealant for leaking ponds. It swells
when wetted and shrinks when dried. I have purchased and spread tons of the
stuff. I have read where it was recommended for use in holes in the ground
in conjunction with grounding applications but have a concern regarding its
shrinkage when drying out. If it is allowed to dry it will shrink and pull
away leaving a gap or poor connection of the ground rod to the surrounding
soil. If you use it, don't let it dry out.
In my dim past (and that isn't necessarily very long ago ;) ;) ) I read
about grounding systems using sulfates (I don't recall which but it wasn't
copper sulfate CuSO4) inside perforated copper pipes. Water was added via
the unburied top of the pipe and the chemical was replenished as it
dissolved and treated the surrounding soil.
As I recall there are some Army tech manuals that cover grounding systems
for radio installations and if memory serves some of the schemes involved
chemical enhancement of soil conductivity.
Patrick AF5CK
-----Original Message-----
From: K1TTT
Sent: Sunday, March 03, 2013 6:00 PM
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Erico chemical ground electrode
Rock salt would tend to corrode the copper pipe, I believe they usually use
copper sulfate or something similar so the electrode isn't destroyed. The
bentonite by itself acts to help increase the conductivity around the rod.
David Robbins K1TTT
e-mail: mailto:k1ttt@arrl.net
web: http://wiki.k1ttt.net
AR-Cluster node: 145.69MHz or telnet://k1ttt.net
-----Original Message-----
From: John E. Cleeve [mailto:g3jvc@jcleeve.idps.co.uk]
Sent: Sunday, March 03, 2013 23:29
To: K1TTT
Cc: towertalk@contesting.com
Subject: Re: [TowerTalk] Erico chemical ground electrode
Hello David,
Thank you for your response. Looking for a source on "Bentonite" it appears
that there are several types of "clay deposit" materials covered by the name
Bentonite, or Fullers Earth as it can be known over here, and it is used for
a suprising number of purposes.
From the Erico diagram, it is claimed that the conductivity is improved by
what appear to be "roots" of conductivity "growing" from the holes in the
base of the electrode, out via the Bentonite layer at the base of the
electrode, into the surrounding ground, and there is no mention of
replenishing the "electrolyte salt" after a specified period.
I would like to try the experiment, using a length of copper central heating
tube. I have a professional ground resistance measuring test set, which I do
know how to use, but its the chemistry that will defeat me.
From what I have read, the Bentonite could be used a "seal" to prevent the
"GEM" material from going further. I assume that the choice of "electrolytic
salts" and the recipe for the "GEM" material would be a closely guarded
commercial secret. But could it be that they are common, and relatively
cheap materials, such as rock salt and copper sulphate, but they have been
given a "new" name for commercial reasons.
Sincerely, John. G3JVC/GM3JVC.
'GEM' could just mean Ground Enhancement Material... which could just
be bentonite or some mix of other conductive material. Usually
chemical grounds like that require periodic replacement of the salts
and would work best in damp areas or could use periodic watering. The
idea is to simply increase the conductivity in the area around the rod
by adding some kind of salt ions to the soil.
David Robbins K1TTT
e-mail: mailto:k1ttt@arrl.net
web: http://wiki.k1ttt.net
AR-Cluster node: 145.69MHz or telnet://k1ttt.net
-----Original Message-----
From: John E. Cleeve [mailto:g3jvc@jcleeve.idps.co.uk]
Sent: Sunday, March 03, 2013 22:18
To: Towertalk@contesting.com
Subject: [TowerTalk] Erico chemical ground electrode
Gentlemen,
Has anyone had experience of using the Erico chemical ground electrode?
The Erico claim is that one chemical ground electrode can be as
effective as multiple ordinary ground rods.
I am not sure if the Erico product is available in the UK, but from
the available Erico literature, it would appear to be a copper tube,
which has been packed with "electrolyte salts", the base of the tube
has a number of holes drilled around the base. The method is to drill
a hole in the ground, larger in diameter than the electrode, put a
layer of Bentonite/Fullers earth in the bottom of the hole, lower the
electrode to the Bentonite, to a depth that covers the holes in the
tube, and then pack the vacant space around the Erico electrode, up to
the ground surface, with Erico "Gem"
material, whatever that might be. The electrodes come with cables
already welded for connection.
I am not a chemist, but I am intrigued, perhaps if we have a chemist
among the group, who could provide a simple explanation of how this
chemical electrode system might work, it would be appreciated.
Sincerely, John. G3JVC/GM3JVC.
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