cone firing

I've received 5# of apparently cone 5 white stoneware. There are 3 kilns
available around here. One firing at around 04; another set are usually at
cone 10 with the third being Raku. The cone 10 kilns are good size to large
college class kilns. The bottom line being no access to real cone 5. Have
looked through my books and can't find my options.
Could any of you give me suggestions for the use of this clay--including
trading/selling it.

i don't know how lucky i've been, BUT i've used cone 6 porcelain slip castings
fired at cone 10 a few times - using cone 10 glases. maybe 8 times i've tried
this. the overall result is sure beautiful. but i recognize that this may be
a form of russian roulete...

i don't know if the higher temp glazes insulate somehow (i would have thought
they would flux the clay body downward), or if true porcelain has a stuborn
affect on overfirings.

just a piece of data....

steve






Subject: cone firing
From: "Stu"
Date: 1/2/2004 11:14 AM Pacific Standard Time
Message-id:

I've received 5# of apparently cone 5 white stoneware. There are 3 kilns
available around here. One firing at around 04; another set are usually at
cone 10 with the third being Raku. The cone 10 kilns are good size to large
college class kilns. The bottom line being no access to real cone 5. Have
looked through my books and can't find my options.
Could any of you give me suggestions for the use of this clay--including
trading/selling it.










steve graber

"Stu" wrote in
:

I've received 5# of apparently cone 5 white stoneware. There are 3
kilns available around here. One firing at around 04; another set are
usually at cone 10 with the third being Raku. The cone 10 kilns are
good size to large college class kilns. The bottom line being no
access to real cone 5. Have looked through my books and can't find my
options. Could any of you give me suggestions for the use of this
clay--including trading/selling it.




A cone 5 clay seems to be a bit of an orphan, but now you've got it, keep
it and use it. The clay will fire over a large range of temperatures.

You should do some firing tests on the clay by putting some small pieces
into the next cone 10 firing. As it will be a formulated white stoneware
clay and not a terra cotta it is more than likely the clay will fire well
at cone 10 and will be hard and well vitrified Large thin bowls might
slump a bit. For the stoneware clay to vitrify at cone 5 there will be a
quantity of some sort of frit in it to bring its vitrifying temperature
down.

I fire a cone 6 white clay to cone 10 and 11 in oxidation, reduction and
anagama. Works well across the range and has excellent colour response.
Some of the areas on the potts seem to self glaze. I imagine that this is
caused by the addition of the frit or frits in the body. Good responce
from manganese dioxide and ash in the anagama

Secondly you could treat it as an earthernware clay. Bisque to 1000 and
glaze with standard earthernware glazes.

Happy daze

John W

Thanks for the data. This is so helpful in the learning process for this
very deceptively simple craft.
"Uncle John" wrote in message
...
"Stu" wrote in
:

I've received 5# of apparently cone 5 white stoneware. There are 3
kilns available around here. One firing at around 04; another set are
usually at cone 10 with the third being Raku. The cone 10 kilns are
good size to large college class kilns. The bottom line being no
access to real cone 5. Have looked through my books and can't find my
options. Could any of you give me suggestions for the use of this
clay--including trading/selling it.




A cone 5 clay seems to be a bit of an orphan, but now you've got it, keep
it and use it. The clay will fire over a large range of temperatures.

You should do some firing tests on the clay by putting some small pieces
into the next cone 10 firing. As it will be a formulated white stoneware
clay and not a terra cotta it is more than likely the clay will fire well
at cone 10 and will be hard and well vitrified Large thin bowls might
slump a bit. For the stoneware clay to vitrify at cone 5 there will be a
quantity of some sort of frit in it to bring its vitrifying temperature
down.

I fire a cone 6 white clay to cone 10 and 11 in oxidation, reduction and
anagama. Works well across the range and has excellent colour response.
Some of the areas on the potts seem to self glaze. I imagine that this is
caused by the addition of the frit or frits in the body. Good responce
from manganese dioxide and ash in the anagama

Secondly you could treat it as an earthernware clay. Bisque to 1000 and
glaze with standard earthernware glazes.

Happy daze

John W

Correct me if I'm wrong but I thought if you didn't fire clay to it's stated
cone# that all the impurities wouldn't get burned out and you'd have air
bubbles and the pot wouldn't be as strong. And that if you fired it way
higher than it's supposed to be that the pot might slump and maybe melt onto
the kiln shelf.
Sandi
"Kathryn Fields" wrote in message
...
Thanks for the data. This is so helpful in the learning process for this
very deceptively simple craft.
"Uncle John" wrote in message
...
"Stu" wrote in
:

I've received 5# of apparently cone 5 white stoneware. There are 3
kilns available around here. One firing at around 04; another set are
usually at cone 10 with the third being Raku. The cone 10 kilns are
good size to large college class kilns. The bottom line being no
access to real cone 5. Have looked through my books and can't find my
options. Could any of you give me suggestions for the use of this
clay--including trading/selling it.




A cone 5 clay seems to be a bit of an orphan, but now you've got it,
keep
it and use it. The clay will fire over a large range of temperatures.

You should do some firing tests on the clay by putting some small pieces
into the next cone 10 firing. As it will be a formulated white stoneware
clay and not a terra cotta it is more than likely the clay will fire
well
at cone 10 and will be hard and well vitrified Large thin bowls might
slump a bit. For the stoneware clay to vitrify at cone 5 there will be a
quantity of some sort of frit in it to bring its vitrifying temperature
down.

I fire a cone 6 white clay to cone 10 and 11 in oxidation, reduction and
anagama. Works well across the range and has excellent colour response.
Some of the areas on the potts seem to self glaze. I imagine that this
is
caused by the addition of the frit or frits in the body. Good responce
from manganese dioxide and ash in the anagama

Secondly you could treat it as an earthernware clay. Bisque to 1000 and
glaze with standard earthernware glazes.

Happy daze

John W

These are some of the reasons for my questions. Looks like there may be a
gulf between what is written in the available books and experienced reality.
"sandi" wrote in message
. ..
Correct me if I'm wrong but I thought if you didn't fire clay to it's
stated
cone# that all the impurities wouldn't get burned out and you'd have air
bubbles and the pot wouldn't be as strong. And that if you fired it way
higher than it's supposed to be that the pot might slump and maybe melt
onto
the kiln shelf.
Sandi
"Kathryn Fields" wrote in message
...
Thanks for the data. This is so helpful in the learning process for this
very deceptively simple craft.
"Uncle John" wrote in message
...
"Stu" wrote in
:

I've received 5# of apparently cone 5 white stoneware. There are 3
kilns available around here. One firing at around 04; another set
are
usually at cone 10 with the third being Raku. The cone 10 kilns are
good size to large college class kilns. The bottom line being no
access to real cone 5. Have looked through my books and can't find
my
options. Could any of you give me suggestions for the use of this
clay--including trading/selling it.




A cone 5 clay seems to be a bit of an orphan, but now you've got it,
keep
it and use it. The clay will fire over a large range of temperatures.

You should do some firing tests on the clay by putting some small
pieces
into the next cone 10 firing. As it will be a formulated white
stoneware
clay and not a terra cotta it is more than likely the clay will fire
well
at cone 10 and will be hard and well vitrified Large thin bowls might
slump a bit. For the stoneware clay to vitrify at cone 5 there will be
a
quantity of some sort of frit in it to bring its vitrifying
temperature
down.

I fire a cone 6 white clay to cone 10 and 11 in oxidation, reduction
and
anagama. Works well across the range and has excellent colour
response.
Some of the areas on the potts seem to self glaze. I imagine that this
is
caused by the addition of the frit or frits in the body. Good responce
from manganese dioxide and ash in the anagama

Secondly you could treat it as an earthernware clay. Bisque to 1000
and
glaze with standard earthernware glazes.

Happy daze

John W

On Sat, 3 Jan 2004 08:53:46 -0800, "Kathy" wrote:

These are some of the reasons for my questions. Looks like there may be a
gulf between what is written in the available books and experienced reality.

The folks that write books are generally very experienced. Certainly
there are different ways of doing things, but info in books is likely
to be "best practice". For example, a well formulated cone 6
stoneware clay will be well vitrified at cone 6. If fired to ^10 it
will almost certainly be overfire and slumping (or worse). If a clay
labeled cone 6 fires well to cone 10, it is very unlikely that it
would properly vitrify at cone 6.

deg

Kathy wrote:

These are some of the reasons for my questions. Looks like there may be a

Kathy,
this thread is a bit difficult to follow, you appear first under "Stu", then
under "Kathrin Fields" and then under "Kathy", you never sign your postings with
a name, it took me a while to realize this is all the same person.

What is written in the available books usually _is_ experienced reality. People
who haven't experienced reality unsually don't write books. And pottery is _not_
a simple craft by no means. Read the books carefully and then experiment on your
own, it takes time to find out what _your_ clay, _your_ glazes, do.
I, for example, have a clay which i couldn't possibly fire only one cone higher
than supposed, it very quickly melts into a glaze. Other clays have a firing
range of several cones without any noticable effects. Most of it is trial and
error, make one small piece, fire it at cone xxx and see what happens.
Here in the newsgroup, you get people from all over the world, using different
clays, different glazes, there is no way we can tell you what your clay will do
under what conditions. Experimenting is fun! Sometimes you find things totally
unexpected, for better or worse!
Enjoy it!

Monika
--
Monika Schleidt

www.schleidt.org/mskeramik

In article ,
Monika Schleidt wrote:
Here in the newsgroup, you get people from all over the world, using different
clays, different glazes, there is no way we can tell you what your clay will do
under what conditions. Experimenting is fun! Sometimes you find things totally
unexpected, for better or worse!
Enjoy it!

Monika

Just one or two things I might add to this thread...

Before Kathy (or Stu) experiments with cone 5 clay in a cone 10 kiln, he/she
should find out if it's permitted by the school doing the firing
(I recall in the original post she/he mentioned using a school's kiln).
The school where I take my classes has a very strict policy about only
firing cone 10 claybodies in their kilns. There have been some disasters
involving melting or exploding pieces when people haven't followed this
policy, and unfortunately the disasters don't only affect the work of the
person using the lower cone clay. Experimentation is a good thing,
but not when it can ruin a kiln's worth of other peoples pieces! I
know I spent a good amount of time with a Dremel getting rid of chunks
of someone's exploded piece in a set of mugs I had done on commission.
Not fun. You don't want to be banned from using the kiln over 5 lbs
of cone 5 clay. It's not worth it!

Deb R.

Sorry about the name switching. I'm Kathy (Stu is my husband who
communicates with newsgroups related to homebuilt rotorcraft and
machining.Check out our web site, www.vkss.com ) Took these several changes
to get my "signature" block corrected for this group. Kathryn Fields is
just a formalization of course, so the choice to change made sense to me
this am.

All of your contributions are quite helpful. Certainly, I would discuss
firing this clay with who ever controls/fires any of the available kilns.
Was just wondering whether to put the clay away until a better time, using
other clays which I have and know they will work in our resources.

I'm too new to this to buy a kiln -- unless there is a very small kiln which
would cover small quantity testing, yet had a wide range of heating
possibilities. As you point out, pottery is not a simple craft and requires
a good deal of study along with all the shere practice I can muster.
Developing throwing skills, glazing, building and understanding clays fully
occuppies my attention, without crowding in this entire further study of
kilns.

Anyway the point is I really appreciate all your contributions to my
education and searing.

Kathy


"Monika Schleidt" wrote in message
...


Kathy wrote:

These are some of the reasons for my questions. Looks like there may be
a

Kathy,
this thread is a bit difficult to follow, you appear first under "Stu",
then
under "Kathrin Fields" and then under "Kathy", you never sign your
postings with
a name, it took me a while to realize this is all the same person.

What is written in the available books usually _is_ experienced reality.
People
who haven't experienced reality unsually don't write books. And pottery is
_not_
a simple craft by no means. Read the books carefully and then experiment
on your
own, it takes time to find out what _your_ clay, _your_ glazes, do.
I, for example, have a clay which i couldn't possibly fire only one cone
higher
than supposed, it very quickly melts into a glaze. Other clays have a
firing
range of several cones without any noticable effects. Most of it is trial
and
error, make one small piece, fire it at cone xxx and see what happens.
Here in the newsgroup, you get people from all over the world, using
different
clays, different glazes, there is no way we can tell you what your clay
will do
under what conditions. Experimenting is fun! Sometimes you find things
totally
unexpected, for better or worse!
Enjoy it!

Monika
--
Monika Schleidt

www.schleidt.org/mskeramik