Often, the answers to a question raises many more questions.
Corrosion Vs area:
To begin, a 5/8ths rod corroding down to a half inch goes through a
cycle in area with the area of the irregular surface becoming quite a
bit more than the 5/8ths inch (0.625") diameter rod with a smooth
surface. Depending on the extent and depth of the corrosion, I'd expect
a substantial increase in the contact area. Once the peak is reached,
the area would diminish rapidly. Because of the irregularity in
corrosion, I have no idea as to what the peak area would be. An 8' rod
would be 96 inches long, a 5/8ths in rod has a circumference of 1.96 inches
1.96 X 96 or an area of 188 sq inches divided by 144 (sq inches in a sq
ft ) = 1.3 sq ft. Even if the area doubled it's only about 2.6 sq ft for
a little while.
If the rods corrode that badly, that fast, I would think the soil needs
to be treated, or sacrificial rods installed.
With the low PH of our soil, the rods look reasonably good after 5 to 10
years. Perhaps there is some electrolysis going on to cause the rapid
corrosion? With steel guys, install an insulator reasonably close to
anchor points? As the ground rods are bonded to the tower that raises
another question. Is there a current flowing through the ground rod?
Can a voltage be measured from the tower to 10 or 15 feet out into the
yard (or surrounding soil) at different times of the year ? With
various equipment powered up?
Just thinking out loud for possible reasons for the advanced corrosion
in addition to the soil conditions.
Here, even ground rods near the edge of the drain field do not show that
kind of advanced corrosion.
When I had the repeater in the garage, There was enough voltage, that
rubbing a 6" screwdriver on the EHS would over ride the received signal.
73
Roger (K8RI)
On 8/16/2015 1:49 PM, Bill Aycock wrote:
Jim--
Lighten up; in this case, the new question, and any answer, should
contribute to clarification. (I think)
With what I have heard about "Salt Doping" and similar means of
enhancement, I see only a strong probability of ambiguity here, as it
is now.
Bill--W4BSG
-----Original Message----- From: Jim Chaggaris
Sent: Saturday, August 15, 2015 10:54 PM
To: <towertalk@contesting.com>
Subject: Re: [TowerTalk] Ground Rod Replacement
Please don't answer a question with a question. It's counter
productive..
73,
Jim N9WW
Jim Chaggaris
President
PowerOne Corp./PowerOne Environmental
2325 Dean St. Suite 200
St. Charles, IL 60175
Phn: 630.443.6500
Cell: 630.669.2241
Fax: 630.443.6505
Website: www.pwrone.com
Sent from my iPad Air
On Aug 15, 2015, at 8:08 PM, <john@kk9a.com> <john@kk9a.com> wrote:
Does corrosion make them not effective?
John KK9A
To: towertalk@contesting.com
Subject: [TowerTalk] Ground Rod Replacement
From: Tony <dxdx@optonline.net>
Date: Sat, 15 Aug 2015 19:22:51 -0400
All:
I've read the service life of copper-clad ground rods can last as
much as 40
years depending on the type of soil they're in.
Be that as it may, I found some corrosion on 4 copper-clad ground
rods that
are bonded to the tower and they've only been in the ground for 15
years.
The corrosion is light at a foot below grade, but I suspect it could be
worse down the length of the rod.
Replacing the rods isn't costly and it's worth knowing the grounds
are in
good shape. The question is what to do with the existing rods?
Is there any benefit in placing the new rods near the old and bonding
them
even though the spacing is close?
Tony
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73
Roger (K8RI)
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