Distoring ware

Hello Fellow potters,
I have a problem with some cheese dishes I've fired to stoneware in an
electric kiln. The inverted bowls that act as the cheese cover distort in
the glaze firing. Cant figure out why. They come out from the bisque firing
OK but when fired to 1265'C instead of coming out circular the sides have
"flats" on them. Any suggestions?

Thanks
Kevin Baldwin.

www.kevinbaldwin.20m.com

Are you firing them directly on to the kiln shelf? If so could be that they
are sticking or catching on the shelf, use something on the shelf - sand or
alumina hydrate to act as minature ball bearings under the pot. A lot of
shrinkage happens in the glaze firing (about half of the total shrinkage).

Other possibility - if when the cover was leather hard you had distortions
that you corrected it may well be circular after biscuit fire but remember
the distortion when the clay softens in the glaze fire.
Good luck
Pierre
www.ukpotters.co.uk

"Kevin" wrote in message
news
Hello Fellow potters,
I have a problem with some cheese dishes I've fired to stoneware in an
electric kiln. The inverted bowls that act as the cheese cover distort in
the glaze firing. Cant figure out why. They come out from the bisque
firing OK but when fired to 1265'C instead of coming out circular the
sides have "flats" on them. Any suggestions?

Thanks
Kevin Baldwin.

www.kevinbaldwin.20m.com

Another suggestion:

I use 1 inch squares of 13mm Ceramic Fibre as separators both in bisc
firing stacks of bowls and similar items (3 pieces in each layer), and
glaze firing inverted bowl forms. In the latter case I paint a bit of
Batt Wash on them, then I can re-use them again and again and again.

Steve
Bath
UK


In article , Pierre Brayford
writes
Are you firing them directly on to the kiln shelf? If so could be that they
are sticking or catching on the shelf, use something on the shelf - sand or
alumina hydrate to act as minature ball bearings under the pot. A lot of
shrinkage happens in the glaze firing (about half of the total shrinkage).

Other possibility - if when the cover was leather hard you had distortions
that you corrected it may well be circular after biscuit fire but remember
the distortion when the clay softens in the glaze fire.
Good luck
Pierre
www.ukpotters.co.uk

"Kevin" wrote in message
news
Hello Fellow potters,
I have a problem with some cheese dishes I've fired to stoneware in an
electric kiln. The inverted bowls that act as the cheese cover distort in
the glaze firing. Cant figure out why. They come out from the bisque
firing OK but when fired to 1265'C instead of coming out circular the
sides have "flats" on them. Any suggestions?

Thanks
Kevin Baldwin.

www.kevinbaldwin.20m.com








--
Steve Mills
Bath
UK

Another thing that might help, if you have the bottom plate, the one
the cheese sits on, how about firing them together, dome sitting on the
plate?
Sandi
Steve Mills wrote:
Another suggestion:

I use 1 inch squares of 13mm Ceramic Fibre as separators both in bisc
firing stacks of bowls and similar items (3 pieces in each layer), and
glaze firing inverted bowl forms. In the latter case I paint a bit of
Batt Wash on them, then I can re-use them again and again and again.

Steve
Bath
UK


In article , Pierre Brayford
writes
Are you firing them directly on to the kiln shelf? If so could be that they
are sticking or catching on the shelf, use something on the shelf - sand or
alumina hydrate to act as minature ball bearings under the pot. A lot of
shrinkage happens in the glaze firing (about half of the total shrinkage).

Other possibility - if when the cover was leather hard you had distortions
that you corrected it may well be circular after biscuit fire but remember
the distortion when the clay softens in the glaze fire.
Good luck
Pierre
www.ukpotters.co.uk

"Kevin" wrote in message
news
Hello Fellow potters,
I have a problem with some cheese dishes I've fired to stoneware in an
electric kiln. The inverted bowls that act as the cheese cover distort in
the glaze firing. Cant figure out why. They come out from the bisque
firing OK but when fired to 1265'C instead of coming out circular the
sides have "flats" on them. Any suggestions?

Thanks
Kevin Baldwin.

www.kevinbaldwin.20m.com








--
Steve Mills
Bath
UK

Kevin wrote:

I have a problem with some cheese dishes I've fired to stoneware in an
electric kiln.

If the dishes are actually made of cheese then there would definately
be some distortion at high fire temp!

(Bit cheeky, I know!)

All the best, Alistair.

Hi,
I think we are on to something here.... I place the inverted bowls direclt
on the shelf. if it did stick slightly then distortion would occur like
Pierre says because of the shinkage. I'll use some fibre as Steve suggests
between the shelf and edge of the bowl. I think the gap round the base will
also help with heat getting inside as well.

Thanks for the replies......I make some more and repost with the results.

Kevin

www.kevinbaldwin.20m.com



"Steve Mills" wrote in message
...
Another suggestion:

I use 1 inch squares of 13mm Ceramic Fibre as separators both in bisc
firing stacks of bowls and similar items (3 pieces in each layer), and
glaze firing inverted bowl forms. In the latter case I paint a bit of
Batt Wash on them, then I can re-use them again and again and again.

Steve
Bath
UK


In article , Pierre Brayford
writes
Are you firing them directly on to the kiln shelf? If so could be that
they
are sticking or catching on the shelf, use something on the shelf - sand
or
alumina hydrate to act as minature ball bearings under the pot. A lot of
shrinkage happens in the glaze firing (about half of the total shrinkage).

Other possibility - if when the cover was leather hard you had distortions
that you corrected it may well be circular after biscuit fire but remember
the distortion when the clay softens in the glaze fire.
Good luck
Pierre
www.ukpotters.co.uk

"Kevin" wrote in message
news
Hello Fellow potters,
I have a problem with some cheese dishes I've fired to stoneware in an
electric kiln. The inverted bowls that act as the cheese cover distort
in
the glaze firing. Cant figure out why. They come out from the bisque
firing OK but when fired to 1265'C instead of coming out circular the
sides have "flats" on them. Any suggestions?

Thanks
Kevin Baldwin.

www.kevinbaldwin.20m.com








--
Steve Mills
Bath
UK

"Red Deer" wrote in message
s.com...
Another thing that might help, if you have the bottom plate, the one
the cheese sits on, how about firing them together, dome sitting on the
plate?

Trouble is that then you would have to leave a an "track" on the dish for
where the lid would touch, which would not look very nice on the finished
product, imo.

I do something similar when I fire my lidded stuff, though - I leave where
the lid hits the bottom dish unglazed and fire with the lid in place. I have
had much better luck with almost no distortions at all since that - or at
least the distortions match up, so the lid sits well :-)

Marianne