Somebody mentioned Bentonite as a good filler material to improve
grounding a few days ago. I asked around about this a bit and one of the
tidbits that I got was the following:
Commercial Bentonite comes in two general varieties (at least for
construction purposes), High Solids and Low Solids. The High Solids form
was reputedly good for grounding while the Low Solids form was not. The
story is that the Low Solids form, while absorbing water as any good
Bentonite should, would still not be very conductive. However, the High
Solids form was indeed very conductive when water was absorbed.
The other bit was that it is Thixotropic, meaning that even after
hardening, it will liquify with a good shaking. So it may be a bad
choice to have around a tower base, especially in an earthquake zone.
If anyone has any more information on this stuff, I'd be interested to
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