Liz Willoughby on wed 10 sep 03
What works for me regarding bentonite. I mix up all the glaze
ingredients first, adding enough water to make it thick before
sieving. I measure out the bentonite and add very hot water to it to
make a thick slurry. It takes more water than one would think, as it
swells so much. I add this to my glaze mixture and sieve everything
together twice.
I also keep a container of bentonite, mixed with water to add as a
suspension to an oxide wash. If you put a cup of bentonite in a
container, fill it with water, over a few days, it will dissolve
without any other fussing.
Meticky Liz from Grafton
>These pieces of advice are actually similar. If you
>put dry bentonite in your glaze and add water without
>premixing, you get a slimy immiscible glob. By dry-
>mixing the materials, the bentonite is distributed
>evenly throughout, so no glob. By pre-wetting the
>bentonite as a slurry, you also prevent the glob.
>Two methods, one outcome. Both right. Eliminating
>bentonite altogether would also prevent The Glob,
>but that seems a bit extreme; bentonite is useful
>stuff.
--
Liz Willoughby
RR #1
2903 Shelter Valley Rd.
Grafton, Ontario
Canada
K0K 2G0
905-349-3130
lizwill@phc.igs.net
Undetermined origin c/o LISTSERV administrator on thu 22 jan 04
Dear Antoinette,
You give a good report of your experience with Bentonite. You say <would be interesting to know more about bentonite and to know to which =
raw material group it belongs.>>
Bentonite is a member of the Phyllosilcate group of minerals which means =
it is formed from basic molecular units which initially assemble =
themselves into flat sheets one molecule deep. In this group each =
molecule is made from two or more simpler units. In the case of =
Bentonite there are three sub units in each molecular collection of =
atoms. The two outer sub units are Silicon ion surrounded by four =
bridging oxygen atoms and the inner sub unit is either an Aluminium or =
a Magnesium ion to which are attached two Hydroxyl (not water but OH) =
ions and four bridging oxygen ions. (See Kingery et al, Introduction to =
Ceramics p 79 fig 2.35; Lawrence and West. p 7, fig 1-3). Sheets of =
these layers are separated by layers of water (H2O) atoms. It is this =
water layer which weakens the bond between layers and allows other water =
molecules to penetrate which is why bentonite swells up. It should also =
be noted that metallic cations Na+, K+, Ca++ can inhabit the water and =
profoundly influence the behaviour of bentonite. Note that Frank Hamer =
tells us that Sodium Bentonites are desirable in pottery bodies because =
of their deflocculating effects. I would disagree, because =
deflocculation destroys the property of tenacity needed in a good =
throwing body.
I hope you are getting these messages, I have just changed Server and =
there are some teething troubles.
Best regards,
Ivor Lewis. Redhill, South Australia
Milla Miller on thu 22 jan 04
a bit off topic but yesterday I saw a semi hauling 4 huge 400 pound bags of
bentonite [the truck was stopped as it ad backended a small compact car] and I
was wondering what the bentonite in that quantity was to be used for? It was
in SC midlands area.the bags must have been special ones and they stated on
the outside that there would be a slippery nature in the case of an accident
with the product.
Brian Haviland on thu 22 jan 04
At 07:45 AM 1/22/04 -0500, you wrote:
>a bit off topic but yesterday I saw a semi hauling 4 huge 400 pound bags of
>bentonite [the truck was stopped as it ad backended a small compact car] and I
>was wondering what the bentonite in that quantity was to be used for? It was
>in SC midlands area.the bags must have been special ones and they stated on
>the outside that there would be a slippery nature in the case of an accident
>with the product.
>------------------------------------------snip--------------------------------------------------
I once used Bentonite to seal the bottom of a man made pond. It was very
slippery
when it got wet. The kids had a blast on thier slide of clay. Reminded me
of stories of
my father growin up in cleveland playing on the blue banks clay along
rocky river.
Brian Haviland
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Hank Murrow on thu 22 jan 04
Dear Milla;
Bentonite is used in drilling operations to lubricate the cutting bit.
It is also used to line ponds to create an impermeable layer on the
bottom to prevent seepage.
Cheers, Hank
On Jan 22, 2004, at 4:45 AM, Milla Miller wrote:
> a bit off topic but yesterday I saw a semi hauling 4 huge 400 pound
> bags of
> bentonite [the truck was stopped as it ad backended a small compact
> car] and I
> was wondering what the bentonite in that quantity was to be used
> for? It was
> in SC midlands area.the bags must have been special ones and they
> stated on
> the outside that there would be a slippery nature in the case of an
> accident
> with the product.
Paul Herman on thu 22 jan 04
Milla,
Most likely well drilling mud. Pumped down the drill stem, the thick
glop flows back to the surface, carrying the cuttings.
best,
Paul Herman
Great Basin Pottery
Doyle, California US
http://www.greatbasinpottery.com/
----------
>From: Milla Miller
>To: CLAYART@LSV.CERAMICS.ORG
>Subject: Re: RE Bentonite
>Date: Thu, Jan 22, 2004, 4:45 AM
>
> a bit off topic but yesterday I saw a semi hauling 4 huge 400 pound bags of
> bentonite [the truck was stopped as it ad backended a small compact car] and I
> was wondering what the bentonite in that quantity was to be used for? It was
> in SC midlands area.the bags must have been special ones and they stated on
> the outside that there would be a slippery nature in the case of an accident
> with the product.
Laura Kneppel on thu 22 jan 04
Is there a clay manufacturer anywhere near there? Or a clumping kitty
litter manufacturer? It's also used in well drilling, making
animal/poultry feed pellets (sticks the ingredients together), metal
casting, steel production, and "Bentonite has also proved helpful in
sealing freshwater ponds, irrigation ditches, reservoirs, sewage and
industrial water lagoons, and in grouting permeable ground. In
addition, it has been used in detergents, fungicides, sprays,
cleansers, polishes, ceramic, paper, cosmetics and applications where
its unique bonding, suspending or gellant properties are required."
The last is quoted from the Black Hills Bentonite Company's website.
You could almost say "what is bentonite NOT used for?" and probably get
a shorter list.
I love Google!
Laurie
Sacramento, CA
On Jan 22, 2004, at 4:45 AM, Milla Miller wrote:
> a bit off topic but yesterday I saw a semi hauling 4 huge 400 pound
> bags of
> bentonite [the truck was stopped as it ad backended a small compact
> car] and I
> was wondering what the bentonite in that quantity was to be used
> for? It was
> in SC midlands area.the bags must have been special ones and they
> stated on
> the outside that there would be a slippery nature in the case of an
> accident
> with the product.
Lee Love on fri 23 jan 04
Milla Miller wrote:
>a bit off topic but yesterday I saw a semi hauling 4 huge 400 pound bags of
>bentonite [the truck was stopped as it ad backended a small compact car] and I
>was wondering what the bentonite in that quantity was to be used for? It was
>in SC midlands area.the bags must have been special ones and they stated on
>the outside that there would be a slippery nature in the case of an accident
>with the product.
>
>
>
Bentonite is used as a lubricant for oil drilling, I've heard.
Lee in Mashiko http://mashiko.us
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