Louis Katz on thu 23 oct 03
Hello Clayart,
I just received a question from a friend about a claybody that is
softening up after it is mixed. It takes several days- weeks for the
softening to happen. It gets softer just on sitting. Another claybody
with some shared ingredients seems to be doing the same thing to a
lesser extant.
Tile Body
Ball Clay C&C 50
Flint 10
Sand 20
Grog 20
The body is used for extruded tile. Another symptom is that the body
now extrudes poorly, the corners tear.
Body 2
Another claybody with C&C 25% and Flint 25% is doing the same thing.
I have assumed that something is going into solution and defloculating
the clay. Anybody have experience with this problem?
Thanks
Louis
lkatz@falcon.tamucc.edu, louis.katz@mail.tamucc.edu
MarjB on fri 24 oct 03
morning Louis
Suggest a ph test on the clays. The water used may be the culprit. Search
CM archives (10 plus years ago) for an article by Angelina Fina about her
problems and solutions with a porcelain clay body. Thrixotrophic, I
believe, is the term used to describe this "nasty" condition. MarjB
----- Original Message -----
From: "Louis Katz"
To:
Sent: Thursday, October 23, 2003 11:17 PM
Subject: Claybody trouble
> Hello Clayart,
> I just received a question from a friend about a claybody that is
> softening up after it is mixed. It takes several days- weeks for the
> softening to happen. It gets softer just on sitting. Another claybody
> with some shared ingredients seems to be doing the same thing to a
> lesser extant.
>
> Tile Body
> Ball Clay C&C 50
> Flint 10
> Sand 20
> Grog 20
>
> The body is used for extruded tile. Another symptom is that the body
> now extrudes poorly, the corners tear.
>
> Body 2
> Another claybody with C&C 25% and Flint 25% is doing the same thing.
>
> I have assumed that something is going into solution and defloculating
> the clay. Anybody have experience with this problem?
>
> Thanks
> Louis
> lkatz@falcon.tamucc.edu, louis.katz@mail.tamucc.edu
>
>
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Louis Katz on fri 24 oct 03
Thanks,
Will do. If I get any answers I will let all know.
Article: IMPROVING PLASTICITY
Author(s): Angela Fina
Issue: January=A0 1984, =
=20
Page 54
Louis
Ron Roy on tue 28 oct 03
Hi Lewis,
Nothing in those clay bodies that I would expect to defoloc - so it must be
the water - what else could it be?
I would add 2 lb. per 1000 dry of disolved Epson Salts - that 0.2 lb per
100 of dry material. That will cure it or I will eat my virtual hat.
Or maybe just mix with demineralized water to see if the problem is alkalie
in the local water.
RR
>I just received a question from a friend about a claybody that is
>softening up after it is mixed. It takes several days- weeks for the
>softening to happen. It gets softer just on sitting. Another claybody
>with some shared ingredients seems to be doing the same thing to a
>lesser extant.
>
>Tile Body
>Ball Clay C&C 50
>Flint 10
>Sand 20
>Grog 20
>
>The body is used for extruded tile. Another symptom is that the body
>now extrudes poorly, the corners tear.
>
>Body 2
>Another claybody with C&C 25% and Flint 25% is doing the same thing.
>
>I have assumed that something is going into solution and defloculating
>the clay. Anybody have experience with this problem?
>
>Thanks
>Louis
>lkatz@falcon.tamucc.edu, louis.katz@mail.tamucc.edu
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
Louis Katz on tue 28 oct 03
Hi Ron,
Not the water. Deep well very soft no seasonal variations. Some batches
have been fine others trouble. I think the trouble is elsewhere. I will
report to the list when it comes out in the wash. Going to check the ph
of the ingredients placed in suspension as an indicator of how much has
gone into solution. There is an Angelina Fina article on this in CM .
Louis
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