Carol & Herman Kremer on thu 7 may 98
-------------------
I am a new potter and was taught to bisque to 08 and glaze fire to 05 or 06.=
I
notice the letters here suggest bisque to 04. I use an electric kiln with a
kiln sitter and backup of large cones. I have been just letting it cool =
without
a soak time. If I should soak, I am unsure how to and for how long. I =
would
appreciate opinions and ideas on this. Thanks.
Carol
eden@sover.net on fri 8 may 98
Hi Carol,
Whatever works for you is fine. Many commercial underglazes are
formulated to be bisqued on at 04. Also most lowfire clays can actually go
up alot hotter, it varies, mine doesn't distort til 03-02 usually. So the
04 bisc makes for a sturdier outcome. Those are the main reasons. I
always assumed a 08 bisc was sufficient because it was when I highfired.
But lowfire is different.
So if you are using underglazes look at the instructions and see what they
say.
Eleanora
At 08:32 AM 5/7/98 -0400, you wrote:
>----------------------------Original message----------------------------
>-------------------
>I am a new potter and was taught to bisque to 08 and glaze fire to 05 or
06. I
>notice the letters here suggest bisque to 04. I use an electric kiln with a
>kiln sitter and backup of large cones. I have been just letting it cool
without
>a soak time. If I should soak, I am unsure how to and for how long. I would
>appreciate opinions and ideas on this. Thanks.
> Carol
>
Eleanora Eden 802 869-2003
Paradise Hill
Bellows Falls, VT 05101 eden@sover.net
Cindy on sat 9 may 98
Carol,
For most of the commercial low-fire glazes I have worked with, a bisque
fire to ^04 is recommended. Coincidentally, that is also the usual cone for
bisque firing medium to high fire ware, which is, I suspect, what most of
the posts you read were referring to. If you've been bisque firing to ^08,
though, and if it's working well for you, there's no reason to change that
I can see.
Soaking is recommended for allowing glazes time to mature. I'm not sure
just how this applies to lower fire glazes. I've not heard of people using
a soak time for lower fired ware, but that doesn't mean it isn't done, of
course. Try it for a half hour or an hour and see if you like the results.
You may also consider soaking at the end of a bisque firing in order to
facilitate the release of volatile gasses and burning out of organic
materials which could affect the quality of your glazes. I soak bisque for
an hour.
Hope this is of help to you. :)
Cindy Strnad
Earthen Vessels
Custer, SD
USA http://blackhills-info.com/a/cindys/menu.htm
Robert Kays on thu 18 oct 01
Are there anything like standard firing and cooling schedules for bisque
and for glaze firings? Accepting that there will always be variables, I
would like to know basically at what temperatures I can speed up and when
to slow down. I am doing mostly sculptural pieces, usually not more than
3/8" thick, bisquing to cone 06 and glaze firing to cone 5 in a (new) gas
kiln. Any suggestions would be appreciated.
Dave Finkelnburg on sat 20 oct 01
Robert,
Everything that follows assumes you have candled well and thoroughly and
have truly bone-dry ware at a temperature of about 180-degrees F. While
there is no such thing as a standard firing schedule, a good starting point
with stoneware is to fire up at roughly 150-degrees F/hour when firing
greenware. With bisque you can usually fire twice that fast safely. If you
are pressed, you can try firing faster after you get the kiln to red heat.
In general, tight bodies should be fired more slowly than open bodies,
thick pieces much more slowly than thin ware.
There is a critical temperatures during cooling. Between 1,100 and
1,000-degrees F (the quartz inversion) you want to be sure to cool slowly.
Too rapid cooling here can cause cracking of the ware.
These are very general statements. Please consider researching the
archives and other sources for more detail. Your mileage may vary....test,
test, test!
Dave Finkelnburg, enjoying an extended Indian summer in Idaho
-----Original Message-----
From: Robert Kays
>Are there anything like standard firing and cooling schedules for bisque
>and for glaze firings?
Peter Cunicelli on tue 18 apr 06
Hi everyone,
This may sound like a, uh, dumb (for lack of a better word) question, but
here goes:
I have a matte white glaze that matures at cone 8 (or so I thought). I
got the recipe from a British guy and says 1240 degrees celsius. I fired
it slowly in my electric kiln to cone 8, then soaked for 15 minutes. That
may have messed it up. It ran a lot.
I've used this glaze as a base to mix with mason stains. One mason stain,
vivd blue, caused the glaze to become VERY stable at cone 10. Is that
possible? When I say very stable, I mean, the glaze came out barely
melted and looked pretty much how it did when I sprayed it on. Turned out
to be a good thing.
I'm reading John Britt's book, but I'm the worst reader. I learn from
experience. This, to me, is one of the most exciting thing about
ceramics. I need to find somewhere I can go to learn glaze formulation
and all about the chemicals.
Thanks in advance for any help you can give me. If anyone knows of
anywhere in the Philadelphia area (besides The Clay Studio) where i could
go to learn about this, I'd love to know about it.
Peter
(www.petercunicelli.com)
Paul Herman on tue 18 apr 06
Peter,
If you look at the formula of many blue stains, they are made of
cobalt and alumina. I think the answer is there. What percentage of
blue stain did you add?
Best,
Paul Herman
Great Basin Pottery
Doyle, California US
http://greatbasinpottery.com
On Apr 18, 2006, at 8:39 AM, Peter Cunicelli wrote:
> I've used this glaze as a base to mix with mason stains. One mason
> stain,
> vivd blue, caused the glaze to become VERY stable at cone 10. Is that
> possible? When I say very stable, I mean, the glaze came out barely
> melted and looked pretty much how it did when I sprayed it on.
> Turned out
> to be a good thing.
Ron Roy on wed 19 apr 06
Hi Peter,
Something fishy here - cobalt is a flux - so I'm thinking there is
something wrong with the recipe.
Are you using cones in your firings?
Send me the recipe and I will see what I can determine from it.
ronroy@ca.inter.net (Ron Roy)
You would be best off with Frank and Janet Hamer's book - The Potters
Dictionary of Material and Techniques. Then you can look up each material
or oxide and get a good idea about how they affect clays and glazes.
RR
>This may sound like a, uh, dumb (for lack of a better word) question, but
>here goes:
>
>I have a matte white glaze that matures at cone 8 (or so I thought). I
>got the recipe from a British guy and says 1240 degrees celsius. I fired
>it slowly in my electric kiln to cone 8, then soaked for 15 minutes. That
>may have messed it up. It ran a lot.
>
>I've used this glaze as a base to mix with mason stains. One mason stain,
>vivd blue, caused the glaze to become VERY stable at cone 10. Is that
>possible? When I say very stable, I mean, the glaze came out barely
>melted and looked pretty much how it did when I sprayed it on. Turned out
>to be a good thing.
>
>I'm reading John Britt's book, but I'm the worst reader. I learn from
>experience. This, to me, is one of the most exciting thing about
>ceramics. I need to find somewhere I can go to learn glaze formulation
>and all about the chemicals.
>
>Thanks in advance for any help you can give me. If anyone knows of
>anywhere in the Philadelphia area (besides The Clay Studio) where i could
>go to learn about this, I'd love to know about it.
>
>Peter
>(www.petercunicelli.com)
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
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