The soil in central Texas is called Caliche with a lot of clay,
CaCO3 & shale. Attempting to drive in a ground rod
yielded only a mushroom on top & blisters on me.
Local tool rental place has concrete bits, but maximum
length of 18 inches. Possibly longer bits are available in
a larger city.

Renting a back hoe is out.
Any suggestions appreciated.
Dave WB3DWE

Dave Lemper wrote in message
...
The soil in central Texas is called Caliche with a lot of clay,
CaCO3 & shale. Attempting to drive in a ground rod
yielded only a mushroom on top & blisters on me.
Local tool rental place has concrete bits, but maximum
length of 18 inches. Possibly longer bits are available in
a larger city.

Renting a back hoe is out.
Any suggestions appreciated.
Dave WB3DWE
-
I lived for many years in the Dallas area. The caliche was down about 2
feet and was about a foot thick. I had to dig a hole with a shovel down to
the caliche, then use a heavy hammer and long chisel to get through the
caliche. Then, backfill and proceed as normal. Don't know what your
configuration would be. Good luck.

On Sat, 23 Aug 2008 16:29:03 GMT, "Wayne"
wrote:

-
I lived for many years in the Dallas area. The caliche was down about 2
feet and was about a foot thick. I had to dig a hole with a shovel down to
the caliche, then use a heavy hammer and long chisel to get through the
caliche. Then, backfill and proceed as normal. Don't know what your
configuration would be. Good luck.


Thanks Wayne.
As a last resort I will hack a trench with a pick and lay in the rod
at a shallow angle to the surface. Would this give an adequate
ground ? I could also bond it to an outdoor brass spigot
10 yards away or even to an anchor fence in the other direction.
Dave WB3DWE

Dave WB3DWE wrote in message
...
On Sat, 23 Aug 2008 16:29:03 GMT, "Wayne"
wrote:

-
I lived for many years in the Dallas area. The caliche was down about 2
feet and was about a foot thick. I had to dig a hole with a shovel down
to
the caliche, then use a heavy hammer and long chisel to get through the
caliche. Then, backfill and proceed as normal. Don't know what your
configuration would be. Good luck.


Thanks Wayne.
As a last resort I will hack a trench with a pick and lay in the rod
at a shallow angle to the surface. Would this give an adequate
ground ? I could also bond it to an outdoor brass spigot
10 yards away or even to an anchor fence in the other direction.
Dave WB3DWE
-
In my opinion the trench would be ok, but I'll leave that to the experts on
the group.

However, I remember chiseling through the caliche to be annoying, but not
that difficult with the right tools. It can be done with a "shooter" style
shovel, but that is a bit more effort. However, I doubt if you would ever
get a copper rod driven through without some major damage to the rod.

Dave Lemper wrote:
The soil in central Texas is called Caliche with a lot of clay,
CaCO3 & shale. Attempting to drive in a ground rod
yielded only a mushroom on top & blisters on me.
[...]
Any suggestions appreciated.
Dave WB3DWE

I'm having thoughts of steel pipes filled with
muriatic (swimming-pool) acid eating through
the caliche chemically. Usual acid-handling
precautions would definitely apply.

Jim, K7JEB

On Sat, 23 Aug 2008 10:58:19 -0500, Dave Lemper wrote:

The soil in central Texas is called Caliche with a lot of clay,
CaCO3 & shale. Attempting to drive in a ground rod
yielded only a mushroom on top & blisters on me.
Local tool rental place has concrete bits, but maximum
length of 18 inches. Possibly longer bits are available in
a larger city.

Renting a back hoe is out.
Any suggestions appreciated.
Dave WB3DWE

Seems like it was only yesterday, but it is, in fact closer to a year:

"Rick (W-A-one-R-K-T)" wrote in
news
On Sat, 04 Aug 2007 11:27:33 -0700, Chuck Olson wrote:

is there any chance you might know what brand and model number of
hammer
drill you used?

Yup, it's the Hilti TE-76-ATC.

Nobody I ever heard of... but it sure works nice.


Rick,

I see on Hilti's web site he TE-76-ATC, and its accessories include a TE-
Y driving shank and a series of adapters TP-TKS ground rod driving
adapters for different diameters.

Hilti BTW are suppliers of expensive quality tools to the construction
industry, you probably won't find their tools in home handyman stores.

The tool you rented is a little lighter than the one I used, and that is
probably why driving times were a little longer. My Hitach PH-65 machine
with home made driving adapter will drive a 16mm diameter 2.4m earth rod
into dry clay in less than a minute.

Pleased it worked for you. It is the way to go, isn't it!

The numbers above might help people looking to rent a device.

Owen

Search Google Groups using advanced search features to include Owen as
the author, and the time period of several weeks before and after the
posting above on the subject of:
"Hammer drills and ground rods, followup"
and
"Hammer drills and ground rods"

73's
Richard Clark, KB7QHC

In article , Dave Lemper
wrote:

The soil in central Texas is called Caliche with a lot of clay,
CaCO3 & shale. Attempting to drive in a ground rod
yielded only a mushroom on top & blisters on me.
Local tool rental place has concrete bits, but maximum
length of 18 inches. Possibly longer bits are available in
a larger city.

Dave-

Last year there was a discussion here about sinking a ground rod using
an "SDS Plus" Hammer Drill set to hammer-only. I think it was Ian
White, GM3SEK, who proposed that method. There is also an article at
http://www.n4lcd.com/groundrod/ that proposes a slightly different
method of coupling the hammer drill to the ground rod.

The question is whether Caliche can be penetrated by such a method. Has
anyone tried it?

Another consideration is whether or not there is moisture in the soil
below the Caliche. If not, then it might not provide a low-impedance
ground even if you could penetrate it!

Fred
K4DII

"Fred McKenzie" wrote in message
...
In article , Dave Lemper
wrote:

The soil in central Texas is called Caliche with a lot of clay,
CaCO3 & shale. Attempting to drive in a ground rod
yielded only a mushroom on top & blisters on me.
Local tool rental place has concrete bits, but maximum
length of 18 inches. Possibly longer bits are available in
a larger city.

Dave-

Last year there was a discussion here about sinking a ground rod using
an "SDS Plus" Hammer Drill set to hammer-only. I think it was Ian
White, GM3SEK, who proposed that method. There is also an article at
http://www.n4lcd.com/groundrod/ that proposes a slightly different
method of coupling the hammer drill to the ground rod.

The question is whether Caliche can be penetrated by such a method. Has
anyone tried it?

Another consideration is whether or not there is moisture in the soil
below the Caliche. If not, then it might not provide a low-impedance
ground even if you could penetrate it!

Fred
K4DII
-
If you don't have all the tools described above for an elegant way to drive
a ground rod, it isn't that bad by hand. The secret is to dig through the
soft dirt to expose the caliche. I used a crowbar hammered with a small
sledge. It isn't too bad for just a ground rod, and might be quicker than
looking for/borrowing more tools.

I planted a 60 foot self supporting tower in a hole 3 ft by 3ft and 6 feet
deep. I would have preferred an elegant solution for that!

On Aug 23, 11:58*am, Dave Lemper wrote:
The soil in central Texas is called Caliche with a lot of clay,
CaCO3 & shale. *Attempting to drive in a ground rod
yielded only a mushroom on top & blisters on me.
Local tool rental place has concrete bits, but maximum
length of 18 inches. *Possibly longer bits are available in
a larger city.

Renting a back hoe is out.
Any suggestions appreciated. *
Dave *WB3DWE * * * * * * * * * * * * *

I know the stuff you are talking about, it will even jam up a
Ditch Witch

When I was in San Antonio with the USAF we made a spade
bit out of metal rod and welded the spades on the side.
We stared the hole with a post hole digger, filled it with water.
then drilled down into it. After drilling a couple of feet we were
able to pound in the ground rods
Im thinking using a real spade bit with an extension may work.

Jimmie

JIMMIE wrote:
I know the stuff you are talking about, it will even jam up a
Ditch Witch

They pave roads with caliche in West Texas. From Wikipedia:
"Caliche is also used for road construction, either as a
surfacing material or, more commonly, as a base material."
--
73, Cecil http://www.w5dxp.com