BVCuma on wed 30 oct 02
>>of what I do with the glycerin in the clay body is to get rid of as much
water as I can. The added plasticity is a plus<<
__________________
Hi Bob
Having followed your lead and added
the glycerin to the body...
As I mentioned previously.. it was disappointing at first,
but 5-6 days later noticed an improvement
in plasticity to "normal" characteristics.
Well I wedged up some of that body today
some twenty days after storage in plastic condition.
Not paying alot of attention...
I did a double take when I realized
It had a *strong* marbling effect happening.
On closer examination it was observed
that the clay had "ripened"
and two distinct colours had formed.
An outer brown layer till one inch
and a 50/50 "marbled" dark green and brown inside...
turning completely green coloured after wedging
(Stuff was gray when I started as are still the tests
that were mixed for comparison the following day)
Plasticity on the wheel is excellent...superb.
like stuff that has been stored for many months
more probably years!
I am curious to see if this bio/chemical-phenomena
does continue till complete green..or what.
The clay that was processed the following day
in comparison indicates nothing unusual there...
nor was any organic fibre blended into the batches
I plan on a more focused testing procedure
to try to pinpoint and maximize the "effect"
Including testing to measure working water content.
If that is in fact reduced and to what extent.
I note that when using glycerin as a glaze additive
the effect has an oil paint like application response.
(at much higher concentrations)
I think you stated that you have been
adding it to the body for 10 yrs now...
was this your idea?
How long do you age the clay before use?
Does it give you such dramatic impact?
Are many others using it in the body?
What is glycerin?
I am quite enthused by your suggestion
and appreciate the door that it has opened.
Thanks,
Bruce
WHC228@AOL.COM on wed 30 oct 02
Bruce
The idea was suggested by two different ceramic engineers.
When I am having a technical problem I usually go to someone in industry to
get some help. The problem was to stop a cracking problem that I was having
with a piece that I make that is quite large. The problem is complex enough
that I am not going to go into a lot of detail.
I do not age my clay after it is made up into pugs. I age my clay as a slurry
for a week or more before I send the slurry through the filter press.
I am told by the engineers that told me about using the glycerin that it is
common in industry, however they did not tell me who is using it.
Bill
Patty Potter on thu 31 oct 02
Very interesting. May I ask in what proportion you add the glycerin to the
clay body?
Patricia
On Wed, 30 Oct 2002 14:52:07 EST, WHC228@AOL.COM wrote:
>Bruce
>The idea was suggested by two different ceramic engineers.
>When I am having a technical problem I usually go to someone in industry to
>get some help. The problem was to stop a cracking problem that I was having
>with a piece that I make that is quite large. The problem is complex enough
>that I am not going to go into a lot of detail.
>I do not age my clay after it is made up into pugs. I age my clay as a
slurry
>for a week or more before I send the slurry through the filter press.
>I am told by the engineers that told me about using the glycerin that it is
>common in industry, however they did not tell me who is using it.
>Bill
>
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