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vinegar in clay

updated fri 28 feb 97

 

mel jacobson on fri 14 feb 97

can't help this one..........the old stories when i was a kid
potter was that the japanese master potters would pee
in their clay...to fertilize it before storage. it would make
the clay grow during ageing.

kids loved that story...and would talk about doing it
in the old clay buckets at school...so i mixed a big jug
of a mixture of ammonia and vinegar/ sorta a pee
substitute....and you know.........i think it works...i still
use it all the time....35 years and i still fertilize my
stored, recycled clay... and please, please...tom buck or
some other chemist....leave me in the dark...do not
explain it....just let me think it works...
mel in minnesota..........full up with seafood...back
home in cold minnesota...missing the sea. p.s. the
Carolinas are full of great people, places to see, and
my gosh...they both border the Atlantic Ocean...what a
concept.

Richard Burkett on sat 15 feb 97



It's my personal opinion that the effect of vinegar is more chemical than
biological. Acids neutralize any defloccuation in the clay. Small amount
of sodium ions in the clay (from the water, leaching from feldspars, etc)
will partially deflocculate clay, quickly lowering the plasticity, even
though the clay is still plastic. If this deflocculation effect is
neutralized, the clay seems immediately more plastic. Plasticity is a
quality of workability, often, but not necessarily related to clay
shrinkage (which has a lot to do with particle sizes which in turn can
effect plasticity), especially when one is dealing with deflocculation.

I have heard some speculation that this acidic effect of vinegar may not
be all that long lasting, and if the spars (or usually worse, nepheline
syenite) continues to leach sodium ions this is indeed the case.

With our rather ion-filled Colorado river water out here in California, I
have the students add a cup or so of vinegar to each mixer-full of the
reprocessed scrap clay. It helps.

Richard Burkett - School of Art, SDSU, San Diego, CA 92182-4805
E-mail: richard.burkett@sdsu.edu <-> Voice mail: (619) 594-6201
Home Page: http://rohan.sdsu.edu/dept/rburkett/www/burkett.html
CeramicsWeb: http://apple.sdsu.edu/ceramicsweb/index.html

Laurie Force on sat 15 feb 97

Well, I WOULD like to know why it works! I keep reading also about using
vinegar and water to attach scored pieces together, and I've also read
somewhere about mixing your slip with vinegar & water for better
adhesion. In our studios at the college we just use plain old slip
though. So, Mel, if anybody can explain about vinegar and clay, just
close your eyes please.

Laurie in Grand Junction, CO

On Fri, 14 Feb 1997, mel jacobson wrote:

> ----------------------------Original message----------------------------
> can't help this one..........the old stories when i was a kid
> potter was that the japanese master potters would pee
> in their clay...to fertilize it before storage. it would make
> the clay grow during ageing.
>
> kids loved that story...and would talk about doing it
> in the old clay buckets at school...so i mixed a big jug
> of a mixture of ammonia and vinegar/ sorta a pee
> substitute....and you know.........i think it works...i still
> use it all the time....35 years and i still fertilize my
> stored, recycled clay... and please, please...tom buck or
> some other chemist....leave me in the dark...do not
> explain it....just let me think it works...
> mel in minnesota..........full up with seafood...back
> home in cold minnesota...missing the sea. p.s. the
> Carolinas are full of great people, places to see, and
> my gosh...they both border the Atlantic Ocean...what a
> concept.
>

Kirk Morrison on sun 16 feb 97

On 14 Feb 97 at 8:42, mel jacobson wrote:

> ----------------------------Original message----------------------------
> can't help this one..........the old stories when i was a kid
> potter was that the japanese master potters would pee
> in their clay...to fertilize it before storage. it would make
> the clay grow during ageing.
>
> kids loved that story...and would talk about doing it
> in the old clay buckets at school...so i mixed a big jug
> of a mixture of ammonia and vinegar/ sorta a pee
> substitute....and you know.........i think it works...i still
> use it all the time....35 years and i still fertilize my
> stored, recycled clay... and please, please...tom buck or
> some other chemist....leave me in the dark...do not
> explain it....just let me think it works...
> mel in minnesota..........full up with seafood...back
> home in cold minnesota...missing the sea. p.s. the
> Carolinas are full of great people, places to see, and
> my gosh...they both border the Atlantic Ocean...what a
> concept.
>
Bacteria in the clay get fed and grow and improve the workablity of the
clay. I heard this from a soil biologist potter friend in my college
days all to long ago.

Kirk Pining for my Mountains in VA, while living in MD
KA4PXK

Sandra Dwiggins on tue 18 feb 97

I use vinegar all the time---but have never used ammonia. I'm willing to
try it--do you mix 1/2 and 1/2?
Sandy