Ron Collins on wed 11 jul 01
It seems to me that most folks fire either 06-04,=20
6, or 10. Is this because commercial claybodies and glazes are used and =
that fact has "standardized" firing temps and glaze recipes? What's =
wrong with cones 1-3? Melinda Collins in Guatemala
John Hesselberth on wed 11 jul 01
on 7/11/01 10:20 AM, Ron Collins at Melron@CONEXION.COM.GT wrote:
> It seems to me that most folks fire either 06-04,
> 6, or 10. Is this because commercial claybodies and glazes are used and that
> fact has "standardized" firing temps and glaze recipes? What's wrong with
> cones 1-3? Melinda Collins in Guatemala
>
Hi Melinda,
I'll give you an answer that is glaze related. I'm sure others will focus
on the clay. At cone 6 you can make nearly a full aesthetic range of glazes
that are also durable. You have to know what you are doing but you can get
mattes, semimattes, glossies,--you can make them mottled or uniform--you can
make them break off texture, etc.....pretty much the full range. About the
only thing you give up is brightness of colors vs. 06-04. And your glazes
are essentially as durable as cone 10 glazes. You really give up very
little vs. cone 10 except that you have to be a little more careful
formulating your glazes. In the book Ron Roy and I are writing we'll show
you glazes some people say can't be done at cone 6--well they can. But I
don't believe you can go much lower and get some of them.
At 06-04 you get the brightness of colors, but are limited to glossy
glazes IF you want them durable. Even then you have to really know what you
are doing to formulate a good one. I won't say it can't be done, but I
haven't yet seen an attractive and durable matte glaze at earthenware
temperatures. I have seen some attractive matte earthenware glazes, but
don't let me get near them with my vinegar. They are usually underfired
glazes that are not at all stable.
Cones 1-3 is, well, somewhere in-between. We have Clayart members who fire
there and are strong proponents of that temperature. Martin Howard fires
there if I remember correctly. I'm sure there are others. If they get the
combination of properties they want, fine. I think more people, by their
preference, break into the 06-04 bright colors, glossy group OR the 6 and
above attractive, durable, muted colors, glossy to matte group and the
commercial suppliers cater to where they perceive the market to be. So
there is nothing inherently wrong with 1-3--it is just where your
preferences lie and the kind of pottery you want to make.
Regards,
John
Web site: http://www.frogpondpottery.com Email: john@frogpondpottery.com
"The life so short, the craft so long to learn." Chaucer's translation of
Hippocrates, 5th cent. B.C.
Martin Howard on thu 12 jul 01
Cones 1-3 is the high end of the earthenware range.
That is why I aim for 2. It gives me strength with a clay a like and the
knowledge that I am not using more energy than is necessary. That is why I
was concerned when my cone 3 was bending at the top and bottom of the kiln.
Now I have lowered the temperature dial and it is leaving the 3 but bending
the 2 at top and the 1 at bottom.
My colours are mainly slip based, or stained glaze over light slip. A lot of
variation can be obtained by putting different glazes over the differing
slips. If they are using the same stain material then they will usually fit
and not fight :-)
It is really all a matter of the choices you make in choosing a clay body,
your Raw Materials, and the kind of ware you want to produce.
But when you have a good fit with body, slips, glazes and cone, then keep to
it unless there is a very good reason to change.
After all you will have put a lot of time and energy in making that first
set of choices. There will probably be buckets galore of glazes based on
those decisions.
Martin Howard
Webb's Cottage Pottery
Woolpits Road, Great Saling
BRAINTREE, Essex CM7 5DZ
England
martin@webbscottage.co.uk
http://www.webbscottage.co.uk
iandol on fri 13 jul 01
Dear Melinda,
Nothing wrong with whatever temperature or cone range you choose to use =
with the usual caveats: Your clay matures in a way that you wish it to =
mature, your glazes mature as you would wish them to become, your clay =
is compatible with your glaze and both offer no hazards in use.
It seems that no one is criticising the choice of ^6 as a stoneware =
maturation point. But perhaps there is a touch of peer group pressure =
from those conservationists who think reducing heat input might assist =
achieving the intentions of the Kyoto Protocol.
Best regards,
Ivor
Ron Roy on sat 14 jul 01
To my way of thinking - lots.
It's in the earthenware range so the mullite that stoneware bodies develop
that makes them chip resistant - is not there.
More difficult to make durable glazes than at cone 6.
Hard to get a vitrified body thet will not sometimes be over or underfired.
More expensive to flux glazes down there.
On the other hand - better than 06 and 04 because of the above reasons.
RR
>It seems to me that most folks fire either 06-04,
>6, or 10. Is this because commercial claybodies and glazes are used and
>that fact has "standardized" firing temps and glaze recipes? What's wrong
>with cones 1-3? Melinda Collins in Guatemala
>
>_____________________________________________________________________
Ron Roy
RR# 4
15084 Little Lake Rd..
Brighton,
Ontario, Canada
KOK 1H0
Residence 613-475-9544
Studio 613-475-3715
Fax 613-475-3513
Jonathan Kaplan on sun 15 jul 01
We have worked at cone 3-4 for many many years in both terra cotta bodies
and white-ware bodies. All are fired in electric kilns. We have glazes tha=
t
are dead ringers for higher fired porcelain and stoneware bodies. We have
perfect clear glazes and no pin holing in any Majolica type wares We use
these formulations for both in house work as well as client related work.
All commercial pigment is exceedingly successful in this temperature range.
It is a function of how the bodies are designed and their constituent
materials.=20
Our clay bodies are quite vitreous and stand up to the rigors of daily use=
.
We have made and formulate both plastic bodies for jiggering, throwing and
RAM=A9 pressing as well as slip casting. In fact, in our consulting business
we have many clients that started working in the 06-04 range and were quite
vociferous in the complaints regarding well developed clear glazes in this
range as well as really poor clay bodies. We designed complete clay and
glaze systems for them in the cone 3-4 range that perform flawlessly.
A rather well known secret is that many of the commercial 06-04 glazes have
quite a wide temperature range.............
Jonathan
--=20
Jonathan Kaplan
Ceramic Design Group
PO Box 775112
Steamboat Springs CO 80477
infor@ceramicdesigngroup.net www.ceramicdesigngroup.net
(use PO BOX for all USPS correspondence)
Plant Location=20
1280 13th Street=20
Steamboat Springs CO 80487
(use PLANT LOCATION for all UPS, Common Carrier, and Courier deliveries)
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