search  current discussion  categories  glazes - cone 4-7 

when should cone 6 bend for mc6g?

updated fri 29 jul 05

 

Ron Roy on mon 25 jul 05


Hi Charan,

If you have a controller - you should start soaking when the cone 6 is at
about 2 oclock - it will take about 20 minutes for the cone to drop from
there.

You will find out what temperature to start soaking at after a few firings
- just remember - all pyrometers give a different reading - just go by the
cones. You will find the speed of firing to be a crucial part of the answer
- so standardize how fast you fire for the last 100 C (200F) - it will be
much easier to predict what will happen and when.

RR

>To Ron/John and all the other experienced MC6G people,
>I am very close to doing a Cone 6 firing using Ron/John's program. This is
>going to be my first Cone 6 firing in my new kiln and I am sure there will
>be things to learn.
>For bisque my kiln does fire a little hotter, so I will have to pay
>attention to what happens at Cone 6. From the archives and the book I know
>that the kiln needs to be fired to self supporting Cone 6 bending till the
>tip touches the shelf. According to the program, there is a 20 minute soak
>at Cone 6. So my question is that should the final programmed temp be such
>that Cone 6 bends and then there is a 20 minute soak, or Should it be such
>that Cone 6 should bend at the end of the 20 minute soak?
>I know it will take a few firings to program it the way the cones should
>bend. But when should Cone 6 bend? or it doesn't matter and it is a matter
>of how I want the glaze to look?
>I might have just answered my question.
>Thanks in advance to everyone
>Charan

Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513

John Hesselberth on mon 25 jul 05


On Jul 25, 2005, at 1:40 PM, Charanjiv Sachar wrote:

> Should it be such that Cone 6 should bend at the end of the 20 minute
> soak?
> I know it will take a few firings to program it the way the cones
> should bend. But when should Cone 6 bend? or it doesn't matter and it
> is a matter of how I want the glaze to look?
> I might have just answered my question.
> Thanks in advance to everyone
> Charan

Hi Charan,

Unfortunately there is no fixed answer to your question. Every kiln is
a little different and thermocouples drift a bit as they age. With my
kilns I find somewhere between 2170 and 2195 usually does the trick.
But when I am firing with a new thermocouple or in a kiln I am not
familiar with I pick a temperature at the upper end of that range. Then
I watch the witness cones and when cone 6 gets to about 2 o'clock I
note the temperature, turn the kiln off and quickly enter a new program
that has that temperature as the peak, the soak I want, and the cooling
cycle. Then turn the kiln back on. It shouldn't take more that 2-3
minutes and the kiln won't drop more than 15-20 degrees. Then if the
cone bends to almost tip touching during the soak I just use the 'skip
to the next ramp' capability of the controller and start cooling a
little early. All this just requires you be thoroughly familiar with
how to program your computer--but that's not such a bad thing to learn.

Then in future firings you will be much closer and, gradually, you will
get your program fine tuned to where the computer does the whole job.
You will have to adjust it a bit, though, every few firings as your
thermocouples age. Good luck.

Regards,

John
John Hesselberth
http://www.frogpondpottery.com
http://www.masteringglazes.com

Charanjiv Sachar on mon 25 jul 05


To Ron/John and all the other experienced MC6G people,
I am very close to doing a Cone 6 firing using Ron/John's program. This is going to be my first Cone 6 firing in my new kiln and I am sure there will be things to learn.
For bisque my kiln does fire a little hotter, so I will have to pay attention to what happens at Cone 6. From the archives and the book I know that the kiln needs to be fired to self supporting Cone 6 bending till the tip touches the shelf. According to the program, there is a 20 minute soak at Cone 6. So my question is that should the final programmed temp be such that Cone 6 bends and then there is a 20 minute soak, or Should it be such that Cone 6 should bend at the end of the 20 minute soak?
I know it will take a few firings to program it the way the cones should bend. But when should Cone 6 bend? or it doesn't matter and it is a matter of how I want the glaze to look?
I might have just answered my question.
Thanks in advance to everyone
Charan


Creative with Clay
Federal Way, WA
Tel: 253 241 2245
Email: creativewithclay@yahoo.com
www.creativewithclay.com
__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com

Charan Sachar on tue 26 jul 05


Thanks John and Ron,
I was thinking for the first firing if I programmed the firing with say
peak temperature of 2170 and a long soak time (one hour). Then during the
soak period when I see Cone 6 bend and touch the shelf, I just skip the
segment and switch to the cool down ramp. The dynacontrol manual says that
skipping during the soak, terminates the soak and switches to next segment.
Then when I fire the next time, I can just program the soak time from my
previous firing (provided I like what the glazes did in the first firing).
I am assuming this might be easier to do than turning off the kiln,
programing the soak and cool down with the temp of the kiln falling. I am
afraid I might just do something wrong trying to do it in a hurry. :) May
be I am assuming too much and need to just do my firing.
It will probabaly take me several firings to figure out what works for my
kiln, the load etc etc.. but I am keeping my fingers crossed.
Thanks
Charan
Creative with Clay
Federal way, WA
www.creativewithclay.com

John Hesselberth on tue 26 jul 05


On Tuesday, July 26, 2005, at 11:36 AM, Charan Sachar wrote:

> I was thinking for the first firing if I programmed the firing with say
> peak temperature of 2170 and a long soak time (one hour). Then during
> the
> soak period when I see Cone 6 bend and touch the shelf, I just skip the
> segment and switch to the cool down ramp.

Hi Charan,

Your way will probably work fine. You might want to have a backup plan
in mind though in case cone 6 has not started to bend at all by the
time you are, say, 30 minutes into your soak. If it does work with, for
example, a 45 minute soak then you can raise the peak temperature a few
degrees for your next firing.

Regards,

John

Ron Roy on thu 28 jul 05


Hi Charan,

That is how I do it - find out what temp you need to get cone 6 started -
then hold for one hour and watch the cone fall - as soon as you get it
where you want it - skip step to the cooling ramps.

Works like a charm - ususlly takes a 20 min soak to get cone 6 half down
for instance and that also depends on how fast the last part of your firing
went - the slower you fire for the last 100C the faster the cone will fall
and the more even you kiln will be.

RR



>Thanks John and Ron,
>I was thinking for the first firing if I programmed the firing with say
>peak temperature of 2170 and a long soak time (one hour). Then during the
>soak period when I see Cone 6 bend and touch the shelf, I just skip the
>segment and switch to the cool down ramp. The dynacontrol manual says that
>skipping during the soak, terminates the soak and switches to next segment.
>Then when I fire the next time, I can just program the soak time from my
>previous firing (provided I like what the glazes did in the first firing).
>I am assuming this might be easier to do than turning off the kiln,
>programing the soak and cool down with the temp of the kiln falling. I am
>afraid I might just do something wrong trying to do it in a hurry. :) May
>be I am assuming too much and need to just do my firing.
>It will probabaly take me several firings to figure out what works for my
>kiln, the load etc etc.. but I am keeping my fingers crossed.
>Thanks
>Charan

Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513