iandol on sun 6 aug 00
Dear Jeff=20
Think we have stirred up the wasps nest now Jeff. The question becomes =
one of what causes thixotropicity. Is it a function of the bentonite =
additives, or are other things becoming colloidal. I have been trying to =
get hold of Frederick Moore=92s book on the Rheology of Ceramic Systems =
but the State library does not have a copy. Perhaps the answers we are =
seeking can be found in that. Though there are Electron Microscope =
photos of Kaolin on the net, none are of kaolin in potters clay.
All the best,
Ivor.
sdpotter@GTE.NET on mon 7 aug 00
Greetings,
I'm jumping in on this thread. I found the following information in 'A
Potter's Handbook'
4 th edition. Now I don't know if this has already been stated, but this i=
s
what I found on
Thixotropicity.
"...This action results from a reduced attraction between the negatively
charged silicate particles
and the positively charged chemical ions in the body. Normally, a clay bod=
y
is stable because
the charges on the ions are neatualized and cause flocculation or thicking.=
However, if large
ions of sodium, lithium or potassium are added, they are not strongly
attracted to the negatively
charged particles, and this causes deflocculation or thinning..."
>From what I've read about this body, the more you use it and work with it,
the runnier it gets.
Hope this helps,
Steve
----------
> From: iandol
> To: CLAYART@LSV.CERAMICS.ORG
> Subject: Thixotropicity. Was orientation of clay particles
> Date: Sun, 6 Aug 2000 16:05:20 +0930
>
>Dear Jeff
>
>Think we have stirred up the wasps nest now Jeff. The question becomes one
of what causes thixotropicity. Is it a function of the bentonite additives,
or are other things becoming colloidal. I have been trying to get hold of
Frederick Moore=92s book on the Rheology of Ceramic Systems but the State
library does not have a copy. Perhaps the answers we are seeking can be
found in that. Though there are Electron Microscope photos of Kaolin on the
net, none are of kaolin in potters clay.
>
>All the best,
>
>Ivor.
>
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