Snail Scott on wed 17 jan 01
At 09:08 PM 1/17/01 -0500, you wrote:
>If you turn off the kiln based on a small cone 6 in the Sitter you are
>probably firing to cone 4 or 5.
>
>Good luck, John
>
> I thought that junior cones melted more SLOWLY than the bigger cones and
>that a cone 6 cone would be more like a six-and-a-half or a cone 7. Hamer's
>Dictionary of Materials and Techniques has a chart giving the melting point
>of large Orton cones as 2305 degrees F. and small cones as 2372 degrees F.
>(I always wondered about the reason, though. Is it because the weight of
>the inclined large cone deforms before the lighter weight and shorter small
>cone?) Cheers, CNC
>
Junior cones are not the same as sitter cones.
-Snail
Michele D'Amico on wed 17 jan 01
HELP!!!I recently set up a home studio with an electric kiln. I have in
the past only worked with a ^10 gas kiln fired in reduction. Now I'm
trying to find happy results with ^6 oxidation. I'm not having much
success. I could use some help with glazes that do not use gerstely
borate and do not look flat and dead. I've looked in the archives but
most glazes there still are formulated with GB and I haven't found that
Laguna Borate is an adequate substitution. I have a Skutt Kiln and
would also welcome some firing tips.
Thanks, Michele
Michele D'Amico
damicom@cruzio.com
John Hesselberth on wed 17 jan 01
Michele D'Amico wrote:
>I have a Skutt Kiln and
>would also welcome some firing tips.
Hi Michele,
The archives are full of cone 6 glazes that people have found =
attractive. Check them out. With regard to firing tips I would =
offer only two which I consider to be most important for people new =
to cone 6 firing of electric kilns----Slow the cooling down and DO =
NOT use your Kiln Sitter=AE to turn off the kiln.
It is OK to drop down to, say 1900 deg F fairly rapidly, but then go =
no more than 150 deg F per hour until you get to 1500. Nearly all =
electric kilns are poorly (meaning unsatisfactoryily) insulated and =
will cool way too fast. You need to fire them down to allow time for =
recrystallization of tiny crystals that will give you improved =
aesthetics on many glazes.
Always turn off your kiln (or begin to fire it down) based on a large =
cone 6 viewed through a peep hole. Cone 6 means large cone 6, tip =
touching the shelf. Large cone 7 will be just starting to bend. Kiln =
Sitters are best used only as safety shut offs. If you turn off the =
kiln based on a small cone 6 in the Sitter you are probably firing to =
cone 4 or 5.
Good luck, John
"The life so short, the craft so long to learn." Hippocrates, 5th =
cent. B.C.
Carolyn Nygren Curran on wed 17 jan 01
If you turn off the kiln based on a small cone 6 in the Sitter you are
probably firing to cone 4 or 5.
Good luck, John
I thought that junior cones melted more SLOWLY than the bigger cones and
that a cone 6 cone would be more like a six-and-a-half or a cone 7. Hamer's
Dictionary of Materials and Techniques has a chart giving the melting point
of large Orton cones as 2305 degrees F. and small cones as 2372 degrees F.
(I always wondered about the reason, though. Is it because the weight of
the inclined large cone deforms before the lighter weight and shorter small
cone?) Cheers, CNC
John Hesselberth on thu 18 jan 01
Hi Carolyn:
The charts are comparing cones that are both standing up in their =
normal position. Use of a cone in a Kiln Sitter=AE is a very =
different situation. It is the weight of that little rod leaning on =
the small cone in the Kiln Sitter=AE that probably makes the =
difference. Kiln Sitters also have to be kept calibrated and many =
people do not do that. The actual shut-off point will, therefore, =
vary depending on how well/often the calibration job is done.
Regards, John
Carolyn Nygren Curran wrote:
> I thought that junior cones melted more SLOWLY than the bigger cones =
and
>that a cone 6 cone would be more like a six-and-a-half or a cone 7. =
Hamer's
>Dictionary of Materials and Techniques has a chart giving the melting =
point
>of large Orton cones as 2305 degrees F. and small cones as 2372 degrees F.
>(I always wondered about the reason, though. Is it because the weight of
>the inclined large cone deforms before the lighter weight and shorter =
small
>cone?) Cheers, CNC
"The life so short, the craft so long to learn." Hippocrates, 5th =
cent. B.C.
Cindy Strnad on thu 18 jan 01
Hi, Carolyn.
My Orton cone chart is downstairs, taped up on the wall next to the kilns,
and I don't feel all that great, so I won't fetch the exact numbers off of
it just now. However, they list the small cones as melting at a cooler
temperature than the large ones.
I believe part of this has to do with the way the cones are used. Cones or
bars placed in the kiln sitter have the weight of the switch bearing down on
them. Large cones have only their own weight to make them bend. At any rate,
it's a generally accepted approximation that smaller cones bend one cone
cooler.
If you used the small cones in a cone pack, I'm sure you'd get different
results, but you'll have to experiment with it if you want to know how
different. I've never heard of anyone using small cones in a cone pack, and
I'm not sure why anyone would want to (unless they were running out of
supplies, maybe), but I expect you could.
Cindy Strnad
Earthen Vessels Pottery
RR 1, Box 51
Custer, SD 57730
USA
earthenv@gwtc.net
http://www.earthenvesselssd.com
Jim Cullen on thu 18 jan 01
Sitter cones are not cones, they are bars. Since they don't have a conical
shape (triangular), but are square they have a completly different dynamic
structure. There are self-supporting cone, large cones, small cones, and
sitter bars. Each has its own characteristics and melting points.
"The mind is like a parachute;
it works much better when it's open'"
KEEP CENTERED
Cullen
Naperville, Illinois
mail to: jcullen845@ameritech.net
----- Original Message -----
From: "Snail Scott"
To:
Sent: Wednesday, January 17, 2001 10:35 PM
Subject: Re: ^6 glaze
> At 09:08 PM 1/17/01 -0500, you wrote:
> >If you turn off the kiln based on a small cone 6 in the Sitter you are
> >probably firing to cone 4 or 5.
> >
> >Good luck, John
> >
> > I thought that junior cones melted more SLOWLY than the bigger cones
and
> >that a cone 6 cone would be more like a six-and-a-half or a cone 7.
Hamer's
> >Dictionary of Materials and Techniques has a chart giving the melting
point
> >of large Orton cones as 2305 degrees F. and small cones as 2372 degrees
F.
> >(I always wondered about the reason, though. Is it because the weight of
> >the inclined large cone deforms before the lighter weight and shorter
small
> >cone?) Cheers, CNC
> >
>
> Junior cones are not the same as sitter cones.
>
> -Snail
>
>
____________________________________________________________________________
__
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at
melpots@pclink.com.
Marcia Selsor on thu 18 jan 01
Dear Jim,
Excuse me but small cones can be cone shape or shaped in bars. I have both.
Marcia in Montana
Jim Cullen wrote:
>
> Sitter cones are not cones, they are bars. Since they don't have a conical
> shape (triangular), but are square they have a completly different dynamic
> structure. There are self-supporting cone, large cones, small cones, and
> sitter bars. Each has its own characteristics and melting points.
>
> "The mind is like a parachute;
> it works much better when it's open'"
>
> KEEP CENTERED
> Cullen
> Naperville, Illinois
> mail to: jcullen845@ameritech.net
> ----- Original Message -----
> From: "Snail Scott"
> To:
> Sent: Wednesday, January 17, 2001 10:35 PM
> Subject: Re: ^6 glaze
>
> > At 09:08 PM 1/17/01 -0500, you wrote:
> > >If you turn off the kiln based on a small cone 6 in the Sitter you are
> > >probably firing to cone 4 or 5.
> > >
> > >Good luck, John
> > >
> > > I thought that junior cones melted more SLOWLY than the bigger cones
> and
> > >that a cone 6 cone would be more like a six-and-a-half or a cone 7.
> Hamer's
> > >Dictionary of Materials and Techniques has a chart giving the melting
> point
> > >of large Orton cones as 2305 degrees F. and small cones as 2372 degrees
> F.
> > >(I always wondered about the reason, though. Is it because the weight of
> > >the inclined large cone deforms before the lighter weight and shorter
> small
> > >cone?) Cheers, CNC
> > >
> >
> > Junior cones are not the same as sitter cones.
> >
> > -Snail
> >
> >
> ____________________________________________________________________________
> __
> > Send postings to clayart@lsv.ceramics.org
> >
> > You may look at the archives for the list or change your subscription
> > settings from http://www.ceramics.org/clayart/
> >
> > Moderator of the list is Mel Jacobson who may be reached at
> melpots@pclink.com.
>
> ______________________________________________________________________________
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at melpots@pclink.com.
--
Marcia Selsor
selsor@imt.net
http://www.imt.net/~mjbmls
http://www.imt.net/~mjbmls/Tuscany2001.html
John Hesselberth on thu 18 jan 01
Diane G. Echlin wrote:
>Now I understand why the results I get in my little kiln with the kiln
>sitter are so very different from the results I get in the big kiln with
>the controller! Fascinating! Now, if I could duplicate the little kiln
>results in the big kiln!
Hi Diane,
It is probably more than just the temperature to which you fired. If you
want the results to be the same you have to match the cooling rates.
Heating rates must also be similar, but they are usually not as much of a
problem as cooling rates.
Regards, John
"The life so short, the craft so long to learn." Hippocrates, 5th cent.
B.C.
John Hesselberth on thu 18 jan 01
Jim Cullen wrote:
>Sitter cones are not cones, they are bars. Since they don't have a conical
>shape (triangular), but are square they have a completly different dynamic
>structure. There are self-supporting cone, large cones, small cones, and
>sitter bars. Each has its own characteristics and melting points.
Hi Jim,
You are right, but many (maybe most) people use small cones, not bars, in
their sitter. In fact lots of clay suppliers don't even carry bars.
Regards, John
"The life so short, the craft so long to learn." Hippocrates, 5th cent.
B.C.
Frederich, Tim on fri 19 jan 01
My Orton cone chart is downstairs, taped up on the wall next to the kilns,
and I don't feel all that great, so I won't fetch the exact numbers off of
it just now. However, they list the small cones as melting at a cooler
temperature than the large ones.
I believe part of this has to do with the way the cones are used. Cones or
bars placed in the kiln sitter have the weight of the switch bearing down on
them. Large cones have only their own weight to make them bend. At any rate,
it's a generally accepted approximation that smaller cones bend one cone
cooler.
Cindy,
The small cones have a higher endpoint temperature on the cone chart because
they were calculated at a much higher heating rate. When doing a firing in
order to get a large cone 6 on the shelf, you may have to put a small cone 7
or 8 in the kilnsitter.
Small cones are used as witness cones in some applications especially in
industry. The small cones called PCE cones from cone 12 on up to cone 42 are
used in industrial labs to calibrate firing processes. You are correct in
thinking that the size of the cone also has an affect on the deformation.
The large cone uses gravity to a greater degree than the small cone.
The rod in the Kilnsitter should not change the point at which the small
cone bends unless it is not adjusted correctly.
Best regards, Tim Frederich
Diane G. Echlin on fri 19 jan 01
Now I understand why the results I get in my little kiln with the kiln
sitter are so very different from the results I get in the big kiln with
the controller! Fascinating! Now, if I could duplicate the little kiln
results in the big kiln!
Diane in CT, loaded down with textbooks and waiting for classes to start
on MondaY!
John Hesselberth wrote:
>=20
> Hi Carolyn:
>=20
> The charts are comparing cones that are both standing up in their norma=
l position. Use of a cone in a Kiln Sitter=AE is a very different situati=
on. It is the weight of that little rod leaning on the small cone in the=
Kiln Sitter=AE that probably makes the difference. Kiln Sitters also ha=
ve to be kept calibrated and many people do not do that. The actual shut=
-off point will, therefore, vary depending on how well/often the calibrat=
ion job is done.
>=20
> Regards, John
>=20
> Carolyn Nygren Curran wrote:
>=20
> > I thought that junior cones melted more SLOWLY than the bigger con=
es and
> >that a cone 6 cone would be more like a six-and-a-half or a cone 7. H=
amer's
> >Dictionary of Materials and Techniques has a chart giving the melting =
point
> >of large Orton cones as 2305 degrees F. and small cones as 2372 degree=
s F.
> >(I always wondered about the reason, though. Is it because the weight=
of
> >the inclined large cone deforms before the lighter weight and shorter =
small
> >cone?) Cheers, CNC
>=20
> "The life so short, the craft so long to learn." Hippocrates, 5th cent.=
B.C.
>=20
> _______________________________________________________________________=
_______
> Send postings to clayart@lsv.ceramics.org
>=20
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>=20
> Moderator of the list is Mel Jacobson who may be reached at melpots@pcl=
ink.com.
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