jimtyler@radiks.net on thu 2 apr 98
I have heard many different suggestions as to which cone to use for a bisque
firing. But so far I have not been happy with the outcomes. I have used 10
but the finished product was very chalky and almost greenware feeling. I used
cone 08 and it was almost identical to the cone 10 products. I then jumped
down to cone 06 but still the bisqueware feels like greenware. My question is
what is the best cone to use for a bisque firing? or does this sound like I am
not firing correctly? I would greatly appriciate your advice.
Celeste
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Cindy on fri 3 apr 98
Celeste,
The best cone for bisque depends on what your finished plans are for the
pottery in question. I believe that most of us who fire to ^6-^10 (not 010,
which, I believe, is what you meant by "10") bisque fire to ^06-^04.
Generally, ^04 is considered pretty much standard.
If you're firing low-maturing ware, most commercial glazes specify a
suggested bisque temp, usually one cone higher than the glaze firing.
For pieces destined for pit or low-temp saggar firing, a ^010 firing might
be more appropriate, as the porosity of the ware is not as diminished as it
would be in a ^04 bisque. Of course, many pit-firers prefer to fire
unbisqued pieces. The reason for the lower bisque is to allow your piece to
absorb carbon and fuming materials more readily. Keep in mind, though, that
with a ^010 bisque, your piece will not be as durable as it would be with a
higher temp firing.
Cindy Strnad
Earthen Vessels
Custer, SD
USA http://blackhills-info.com/a/cindys/menu.htm
> I have heard many different suggestions as to which cone to use for a
bisque
> firing. But so far I have not been happy with the outcomes. I have used
10
> but the finished product was very chalky and almost greenware feeling. I
used
> cone 08 and it was almost identical to the cone 10 products. I then
jumped
> down to cone 06 but still the bisqueware feels like greenware. My
question is
> what is the best cone to use for a bisque firing? or does this sound like
I am
> not firing correctly? I would greatly appriciate your advice.
>
> Celeste
>
> -----== Posted via Deja News, The Leader in Internet Discussion ==-----
> http://www.dejanews.com/ Now offering spam-free web-based newsreading
Randy Tippetts on fri 3 apr 98
I learned for bisque firing you use a cone 04; and if you have a combined load o
glaze and greenware then you use a cone 05; and if it is just glaze 06. Here is
chart that I have:
Bisque 06-04
glazes 06
porcelain 6
Mother of pearl 20
gold, white gold 19
china paints 19
decals 015-016
I hope that helps some; that information came from a card I received from duncan
Kim
ddrw@xmission.com
jimtyler@radiks.net wrote:
> ----------------------------Original message----------------------------
> I have heard many different suggestions as to which cone to use for a bisque
> firing. But so far I have not been happy with the outcomes. I have used 10
> but the finished product was very chalky and almost greenware feeling. I used
> cone 08 and it was almost identical to the cone 10 products. I then jumped
> down to cone 06 but still the bisqueware feels like greenware. My question is
> what is the best cone to use for a bisque firing? or does this sound like I am
> not firing correctly? I would greatly appriciate your advice.
>
> Celeste
>
> -----== Posted via Deja News, The Leader in Internet Discussion ==-----
> http://www.dejanews.com/ Now offering spam-free web-based newsreading
ceramics@epix.net on fri 3 apr 98
In article <6fumve$k5$1@nnrp1.dejanews.com>,
jimtyler@radiks.net wrote:
>
> ----------------------------Original message----------------------------
> I have heard many different suggestions as to which cone to use for a bisque
> firing. But so far I have not been happy with the outcomes. I have used 10
> but the finished product was very chalky and almost greenware feeling. I
used
> cone 08 and it was almost identical to the cone 10 products. I then jumped
> down to cone 06 but still the bisqueware feels like greenware. My question
is
> what is the best cone to use for a bisque firing? or does this sound like I
am
> not firing correctly? I would greatly appriciate your advice.
>
> Celeste
>
Hi Celeste
First a couple questions: 1) what are you firing ? - low or high fire clay
body ("hobby ceramic", porcelain, stoneware, etc. 2) were the cones used
self-supporting on the shelf or junior cones in the kiln sitter 3) did you
pour or purchase the greenware ?
Now on to some possible answers for low fire "hobby ceramic" slip, junior
cone (bar or "triangle") in kiln sitter: For utility pieces I fire to cone 02
for durability, for general firing cone 04, if the piece has been roll glazed
on the inside ONLY use cone 06 (outside to be done in stains). If you
purchased the greenware and it was really old this could be your problem
if it is starting to "break down". If you poured it how did this batch of slip
compare to your last batch. If you pour and reclaim were your ratios correct.
Yes, it could be your firing, but need more info before going there.
Hope this helps, holler if you need more.
Adrienne (Mud Hen)
CERAMICS & SUCH
Palmyra PA
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Jarita Thomson on sat 4 apr 98
Hello, Kim,
I haven't wrote in before because most of the discussions are on
pottery which I have very limited knowledge in. This thread, though with
low-fire ware is my stronger area. When you transferred your information
regarding firing, you missed the "0" for the gold and mother of pearl
fires. That is, they are supposed to be fired at ^019 and ^020
respectively.
As for the firing of greenware to bisque, agreed the temperature
range is between ^06 and ^04, but if one fires the greenware at a
different cone, they will find subtle differences in their bisque. Most
bisque should have been fired to at least a witness cone 04. It needs to
reach this maturity to take glaze well. Many problem areas on glazed
ware come from immature bisque. On the other hand, if the piece is going
to be strictly decorative and glaze will not be applied, bisque stains
create a better effect on slightly softer bisque. If finishing in bisque
stains, I usually prefer firing to ^05.
When using commercial glazes, most jars state which cone to fire
to. The majority of low-fire glazes are fired to ^06. If the glaze is
metallic, it sometimes needs to be fired to ^04. I always recommend
reading the lable. I do not suggest combining loads with both greenware
and glaze for simple cross-contamination reasons. Occasionally, though,
I have fired clear glaze at ^05 with soft bisque, but I noticed a very
slight greying to the glaze.
I hope this information is helpful.
Sincerely, Jarita
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SP1RALPATH on mon 6 apr 98
Try cone 04. Cone 10 (?) is far too high for a bisque firing---did you maybe
mean 010? At cone 04 the glazes seem to go on nicely--cone 06 was okay too
for me.
John H. Rodgers on tue 7 apr 98
-- [ From: John H. Rodgers * EMC.Ver #2.5.02 ] --
Just seems like that this thread needs a comment about the cone ranges to
eliminate confusion.There may be newbie lurkers out there that don't know,
and some of us who have been around a while that need a reminder once in a
while.
Cone ranges are from coolest to hottest and start at 020(coolest I have ever
seen). The numbers that are preceded by "0" or zero represent the negative
side of zero. The count moves towards zero and reflects the relative heat
at which they mature or begin to soften. So 020 is cool, 019 is cool but
hotter than 020, etc. 018 is relatively cool, but hotter that 019, etc. So
the cones go.
So the scale runs like this: 020,019,018,...........010,08,06,05,04,02,01,0,
^1,^2,^3,^4,^5^6^7^8,^9,^10^11
Golds, china paints, some glazes are fired in the low end.....020 for gold,
018 to 014 for china paint, same for some glazes.
Other glazes, especially reds are often fired in the 06 to 04 range to
prevent them from burning out.
Many people bisque fire around 06, 05(hotter than 06), 04(hotter than 05)
depending on the clay. Bisque in these ranges takes and holds glaze better
until a high temp glaze fire is done. Above zero clay and glaze performance
really starts to be stressed. Beginning around ^5-^6 it is considered high
fire. This is about the lowest temp at which you can get porcelain to mature
.. Many glazes mature at this temperature. I would venture that the biggest
share of electric work is done in this range. Above that, approaching ^10
and above, you are getting into the upper realm of high fire and though some
electric work is done at these temps, this is where the fuel fired kilns
really come into their own, with their ability to do strong reductions at
those high temperatures.
Hope this helps someone along the road of learning that we have all traveled
at one time or another.
If I have missed anything or something needs adding, or a correction made,
please feel free to join in here.
Joy in Clay!
John Rodgers in Alabama
-------- REPLY, Original message follows --------
Date: Monday, 06-Apr-98 09:17 AM
From: Jan Mandrake \ America On-Line: (SP1RALPATH)
To: Clayart \ Internet: (clayart@lsv.uky.edu)
Subject: Re: bisque firing techniques
----------------------------Original message----------------------------
Try cone 04. Cone 10 (?) is far too high for a bisque firing---did you
maybe mean 010? At cone 04 the glazes seem to go on nicely--cone 06 was
okay too for me.
-------- REPLY, End of original message --------
Brad Sondahl on wed 8 apr 98
John Rodgers did a nice summary of temperature issues and bisque. The
important things to remember about choosing a bisque temperature are:1.
making the clay sturdy enough to handle, but not too vitrified to accept
glaze, and 2. allowing the organic and sulphur compounds to be burned
out so as not to have bloating when the clay is fired high (this concern
only with cone6-10 bodies). I've found cone 05 best for my purposes,
but probably 06-04 is good for most bodies.
--
Brad Sondahl
http://www.camasnet.com/~asondahl
Contributing to the potluck of the WWW
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