William & Susan Schran User on fri 20 may 11
On 5/20/11 6:15 PM, "Robert A. Fox" wrote:
> Hi, I have a crystalline glaze that I am using on Coleman porcelain. The
> glaze is somewhat runny, but not as much as most crystalline glazes. When=
it
> runs, it usually forms a thicker ring of glaze at the very bottom of the =
pot
> and not much runs into the glaze catcher.
> At the bottom where the glaze has built up, the glaze is shivering off th=
e
> pot. Sometimes it takes a little clay off with it and sometimes it does n=
ot.
> This is happening with maybe 35% of the pieces where there is a lot of gl=
aze
> build up.
> What would be the best way to fix this? Should I alter the glaze recipe i=
n
> some way, or is it a problem because of the large amount of crystal growt=
h
> that occurs where the glaze is very thick at the bottom? It is very
> frustrating to have a great pot and then have it shiver.
Robert, I have been doing crystalline glazes for quite some time but have
not encountered this issue. Perhaps you could send me some images so I coul=
d
better see for my self the problem. Would like to see the pot still in the
catcher and after separation. I have some notions, but I would have to see
what you describe.
Bill
--
William "Bill" Schran
wschran@cox.net
wschran@nvcc.edu
http://www.creativecreekartisans.com
Robert A. Fox on fri 20 may 11
Hi, I have a crystalline glaze that I am using on Coleman porcelain. The=
=3D
glaze is somewhat runny, but not as much as most crystalline glazes. When=
=3D
it
runs, it usually forms a thicker ring of glaze at the very bottom of the =
=3D
pot
and not much runs into the glaze catcher.=3D20=3D20
At the bottom where the glaze has built up, the glaze is shivering off th=
=3D
e
pot. Sometimes it takes a little clay off with it and sometimes it does n=
=3D
ot.
This is happening with maybe 35% of the pieces where there is a lot of gl=
=3D
aze
build up.
What would be the best way to fix this? Should I alter the glaze recipe i=
=3D
n
some way, or is it a problem because of the large amount of crystal growt=
=3D
h
that occurs where the glaze is very thick at the bottom? It is very
frustrating to have a great pot and then have it shiver.=3D20
Thank You
Ron Roy on mon 23 may 11
Hi Robert,
Sometimes that happens when a glaze dips and touches a shelf - if the
glaze it well attached to the shelf then - as the pot contracts as it
cools the glaze will break away - happens with porcelains when they
fuse to a shelf too.
If that is what is happening then a thin layer of alumina between the
pot and glaze and your catcher should stop the problem.
RR
Quoting "Robert A. Fox" :
> Hi, I have a crystalline glaze that I am using on Coleman porcelain. The
> glaze is somewhat runny, but not as much as most crystalline glazes. When=
it
> runs, it usually forms a thicker ring of glaze at the very bottom of the =
pot
> and not much runs into the glaze catcher.
>
> At the bottom where the glaze has built up, the glaze is shivering off th=
e
> pot. Sometimes it takes a little clay off with it and sometimes it does n=
ot.
> This is happening with maybe 35% of the pieces where there is a lot of gl=
aze
> build up.
>
> What would be the best way to fix this? Should I alter the glaze recipe i=
n
> some way, or is it a problem because of the large amount of crystal growt=
h
> that occurs where the glaze is very thick at the bottom? It is very
> frustrating to have a great pot and then have it shiver.
>
> Thank You
>
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