Pfeiffer, Dan R (Dan) on tue 16 nov 04
After reviewing a number of books and videos on firing I still can't
find any
answers to a very basic question. The answer to this seems to be so obvious,
or
just does not happen, that the writers never give it any mention.
In firing to cone 10 is the object to have the cone down at the end of the
firing
or is that only the place you stop firing?
After much playing with my LP gas updraft this last weekend I had a perfect
^10
bending to 90 deg on all shelves.
This was done quite slowly with a 20 min soak as it got to ^10.
I turned the gas off and closed up up the kiln after look that the cones
were at a
perfect ^10 and the next day after the kiln had cooled all the cones had
bent to ^11.
The question is knowing it will go one cone higher than were I turned the
gas off
should I be stopping at ^9?
Is anyone putting in cones above the cone they are planning to stop at?
Did I over fire the kiln/glazes or is this what should have happened?
Glazes came out very nice!
Dan in Elkmont Al
dalecochoy on tue 16 nov 04
----- Original Message -----
From: "Pfeiffer, Dan R (Dan)" Subject: firing cones ?
> After reviewing a number of books and videos on firing I still can't
> find any
> answers to a very basic question. The answer to this seems to be so
obvious,
> or
> just does not happen, that the writers never give it any mention.
> In firing to cone 10 is the object to have the cone down at the end of
the
> firing
> or is that only the place you stop firing?
> After much playing with my LP gas updraft this last weekend I had a
perfect
> ^10
> bending to 90 deg on all shelves.
Great Dan, I see you finally got that Olympic working better throughout!
Dale
> This was done quite slowly with a 20 min soak as it got to ^10.
> I turned the gas off and closed up up the kiln after look that the cones
> were at a
> perfect ^10 and the next day after the kiln had cooled all the cones had
> bent to ^11.
> The question is knowing it will go one cone higher than were I turned the
> gas off
> should I be stopping at ^9?
> Is anyone putting in cones above the cone they are planning to stop at?
> Did I over fire the kiln/glazes or is this what should have happened?
>
> Glazes came out very nice!
>
> Dan in Elkmont Al
Dan,
I found with my Olympic firing cone ten clays to cone ten 90 degrees to
full down I got too much warping and sagging on larger pots ( BTW, You know
I fire real slow) but found everything to come out perfect if I stop just
as I see the cone 10 cone start to lean. ( BTW, I noticed less difference in
glazes at cone 9 or cone ten limit than I did with clay problems) Since I
got it all dialed in I can get them to match now at top and bottom shelves.
But, I never fire-down or "hold". I don't find that with the stuff I'm
making I need to and I have never had the cones drop any further after just
shutting off and closing up the kiln when cones get where I want them.
Regards,
Dale Cochoy, Wild Things Bonsai Studio, Hartville, Ohio
DaleCochoy@Prodigy.Net http://www.WildThingsBonsai.Com
Specializing in power wood carving tools.
Yakimono no Kokoro bonsai pottery of hand-built stoneware
Hank Murrow on tue 16 nov 04
On Nov 16, 2004, at 8:25 AM, Pfeiffer, Dan R (Dan) wrote:
> After reviewing a number of books and videos on firing I still
> can't
> find any answers to a very basic question. In firing to any given
> cone is the object to have the cone down at the end of the firing or
> is that only the place you stop firing?
> The question is knowing it will go one cone higher than were I turned
> the
> gas off or should I be stopping at ^9? Is anyone putting in cones
> above the cone they are planning to stop at? Did I over fire the
> kiln/glazes or is this what should have happened?
>
> Glazes came out very nice!
Dear Dan;
The cones just give you a record of what is going on and has gone on
inside a particular kiln. They are a record of heat work. It does not
matter what bend the cones reach, except as your kiln, glazes, and
aesthetic preferences dictate the results. The cones are just a way of
repeating(more or less) the result. So the right way to finish a firing
is the way that the cones indicate a result that you prefer.
Cheers, Hank in Eugene
www.murrow.biz/hank
Mike Gordon on tue 16 nov 04
On Nov 16, 2004, at 8:25 AM, Pfeiffer, Dan R (Dan) wrote:
>
> Glazes came out very nice!
>
> Dan in Elkmont Al
Dan,
If the glazes came out the way you want them to , what difference does
it make??? Fire it the same way each time. Mike Gordon
>
> _______________________________________________________________________
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> Send postings to clayart@lsv.ceramics.org
>
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>
Craig Clark on tue 16 nov 04
Dan, if the glazes turned out well and are doing what you want them
to do then you fired to the correct cone. If you were looking
specifically for cone 10 and you ended up with a bent 11 then you did
overfire. That will have had an impact on the quality of your glazes.
They most probably are more glossy than they would have been if you had
actually fired to a cone 10.
The method for firing your particular kiln is kinda like adding
spices to a sauce. It is a matter of taste, within certain parameters.
Be sure to keep detailed notes of each firing and what the end results
were. The next time start to slow the rate of climb in the kiln earlier
than you did this time. Remember that your cones are measuring "work
heat", not temperature. You will need to fugure out at what point you
need to soak, for how long, and when you turn the kiln off and button it
up. One thing you may do is to fire down as has been frequently
discussed on the list. Just check the archives for extensive info.
Hope this helps
Craig Dunn Clark
619 East 11 1/2 st
Houston, Texas 77008
(713)861-2083
mudman@hal-pc.org
Snail Scott on thu 18 nov 04
At 10:25 AM 11/16/2004 -0600, you wrote:
> In firing to cone 10 is the object to have the cone down at the end of the
>firing
>or is that only the place you stop firing?
>Glazes came out very nice!
A '^10 firing' means that when you unload,
^10 will be bent with the tip just touching,
BUT...
The object is never to have the cones bend to
a certain degree; it's to have your work come
out the way you want. This may seem like
splitting hairs, but it's important! It does
not matter whether 'true ^10' is tip-down,
for instance, if your glazes are best with ^10
slightly bent, or with ^11 starting to bend,
and it doesn't change anything to say that the
recipe was labeled as ^10. It's completely
irrelevant. Only YOUR results matter. If you
fire until ^10 goes down, but the ongoing
heat-work keeps on 'cooking' such that ^11
drops, and you work looks great that way, then
fire that way! Yes, that technically makes it
a ^11 firing, but who cares? So it's ^11.
If you really want a ^10 firing, for your kiln
it sounds like you'd have to put the brakes on
around ^9, but why do you want a ^10 firing?
Just because the label on your clay or glaze
recipe says ^10? Even if you are firing to
reproduce someone else's ^10 results, their
kiln isn't yours, and your work isn't theirs.
Fire in the way that makes your work great,
regardless of the nominal cone.
-Snail
Pfeiffer, Dan R (Dan) on thu 18 nov 04
Many thanks to all for the comments on cones and there meaning. I think I
now have a grip on what to do on my next firing and how to interrupt it.
While I can see that the glaze is what counts in the end, as we are just
learning to fire it would be good to get control of the process and have a
goal. The real problem at the being is having a sense of what is "normal".
It would seem that this mistake had some very good effects but it must be
hard on the kiln and shelves. I think it mite be better to add more flux to
the glaze and not fire as high if we don't like the current set of glazes
when fired to ^10. I am sure we will have many an odd and unplanned event
happen and we will hopefully lean from them!
Dan in Elkmont Al
>>Fire in the way that makes your work great,
regardless of the nominal cone.
-Snail <<
Ivor and Olive Lewis on thu 18 nov 04
Dear Dan,
To add to what has already been said.
Even though you may have discontinued the input of energy after the
cone you have selected has made its point, as it were, there is still
a high heat load in the walls of the kiln, substantial if it is hard
brick, appreciable if it is RI brick and moderate if it is ceramic
fibre. With the rest of your work, your cones continue to be affected
by this radiation. The chemical and physical process taking place slow
down slowly. So cones continue to loose physical integrity, continue
to collapse even though the temperature is falling, slowly in the case
of Hard brick, moderately in the case of RI and rather quickly in the
case of Fibre.
If results from you firings are what you need and you achieve them
consistently under your firing conditions, accept these gifts from
your Kiln Goddess.
Best regards,
Ivor Lewis.
Redhill,
S. Australia.
----- Original Message -----
From: "Hank Murrow"
To:
Sent: Wednesday, 17 November 2004 6:20
Subject: Re: firing cones ?
> On Nov 16, 2004, at 8:25 AM, Pfeiffer, Dan R (Dan) wrote:
>
> > After reviewing a number of books and videos on firing I
still
> > can't
> > find any answers to a very basic question. In firing to any given
> > cone is the object to have the cone down at the end of the firing
or
> > is that only the place you stop firing?
>
> > The question is knowing it will go one cone higher than were I
turned
> > the
> > gas off or should I be stopping at ^9? Is anyone putting in cones
> > above the cone they are planning to stop at? Did I over fire the
> > kiln/glazes or is this what should have happened?
> >
> > Glazes came out very nice!
>
> Dear Dan;
>
> The cones just give you a record of what is going on and has gone on
> inside a particular kiln. They are a record of heat work. It does
not
> matter what bend the cones reach, except as your kiln, glazes, and
> aesthetic preferences dictate the results. The cones are just a way
of
> repeating(more or less) the result. So the right way to finish a
firing
> is the way that the cones indicate a result that you prefer.
>
> Cheers, Hank in Eugene
> www.murrow.biz/hank
>
>
______________________________________________________________________
________
> 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.
Ron Roy on fri 19 nov 04
Just a little more information here may make the difference.
It is important to know about the clay as well - some clays labeled for
cone 10 may be at the end of their ability to handle more heat - in that
case - if your glazes look better fired higher - the obvious answer is to
adjust the glaze to fire the way you want it.
RR
>A '^10 firing' means that when you unload,
>^10 will be bent with the tip just touching,
>BUT...
>
>The object is never to have the cones bend to
>a certain degree; it's to have your work come
>out the way you want. This may seem like
>splitting hairs, but it's important! It does
>not matter whether 'true ^10' is tip-down,
>for instance, if your glazes are best with ^10
>slightly bent, or with ^11 starting to bend,
>and it doesn't change anything to say that the
>recipe was labeled as ^10. It's completely
>irrelevant. Only YOUR results matter. If you
>fire until ^10 goes down, but the ongoing
>heat-work keeps on 'cooking' such that ^11
>drops, and you work looks great that way, then
>fire that way! Yes, that technically makes it
>a ^11 firing, but who cares? So it's ^11.
>
>If you really want a ^10 firing, for your kiln
>it sounds like you'd have to put the brakes on
>around ^9, but why do you want a ^10 firing?
>Just because the label on your clay or glaze
>recipe says ^10? Even if you are firing to
>reproduce someone else's ^10 results, their
>kiln isn't yours, and your work isn't theirs.
>Fire in the way that makes your work great,
>regardless of the nominal cone.
>
> -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.
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
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