Sandra Talarico (home) on sun 19 jan 03
I own a Skutt with controller.
I'm ready to create my own ramp/hold firing schedule
for a cone 6 glaze fire that cools at 150/hr degrees farenheit.
But, I have a question about the ramp after 212 degrees and about
200 degrees before the cone 6 finish temp
.
One book says to let it rip at 500/hr until about 200 degrees
before the cone 6 temp. But, other books say move slowly
through the quartz inversion which happens at 1064 degrees
(or between the 900 to 1100 degree range).
Does anyone have any suggestions about the ramp speed
between 212 and about 2000 (my kiln hits cone 6 around 2207)?
Thanks,
Sandy Talarico
James Bledsoe on mon 20 jan 03
yes by all means slow down going through chemical water and quartz the
amount you slow by is dependent on the thickness of your work. This brings
up another point, the soak time @212. What i do is unconventual. Shut the
lid and soak for as long as it takes to feel no moisture on your hand when
you open the lid. By keeping the lid shut the atmosphere is stabilized and
the temperature can not go above 212 due to the physics of water, heat and
gas laws. The time it takes to dry out your kiln will be different each
time you fire. Most work is lost at this stage of the firing
j
----- Original Message -----
From: "Sandra Talarico (home)"
To:
Sent: Sunday, January 19, 2003 1:57 PM
Subject: help with controller kiln firing sched
> I own a Skutt with controller.
> I'm ready to create my own ramp/hold firing schedule
> for a cone 6 glaze fire that cools at 150/hr degrees farenheit.
>
> But, I have a question about the ramp after 212 degrees and about
> 200 degrees before the cone 6 finish temp
> .
> One book says to let it rip at 500/hr until about 200 degrees
> before the cone 6 temp. But, other books say move slowly
> through the quartz inversion which happens at 1064 degrees
> (or between the 900 to 1100 degree range).
>
> Does anyone have any suggestions about the ramp speed
> between 212 and about 2000 (my kiln hits cone 6 around 2207)?
>
> Thanks,
> Sandy Talarico
>
>
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John Hesselberth on mon 20 jan 03
On Sunday, January 19, 2003, at 04:57 PM, Sandra Talarico (home) wrote:
> One book says to let it rip at 500/hr until about 200 degrees
> before the cone 6 temp. But, other books say move slowly
> through the quartz inversion which happens at 1064 degrees
> (or between the 900 to 1100 degree range).
>
> Does anyone have any suggestions about the ramp speed
> between 212 and about 2000 (my kiln hits cone 6 around 2207)?
Hi Sandy,
We had a discussion of this about 2 weeks ago so you can find some other
opinions in the archives; however I don't recall anyone saying they have
personally had trouble with "letting it rip". The only time I would be
tempted to be careful would be when I had an unusually large or thick
piece. But then, I would probably fire more slowly all the way up--not
just through the quartz inversion. Even if you set your controller at
500 deg F/hr it is unlikely you will go up that fast unless your kiln is
virtually empty. I think the fastest mine will go when fully loaded is
in the 300 or so range.
Regards,
John
http://www.frogpondpottery.com
http://www.masteringglazes.com
Nanci Bishof on tue 21 jan 03
The schedule I use for my ^6 firing is:
75F/hr > 220F
300F/hr>800F
100F/hr>1200F
300F/hr>2000F
150F/hr>2174F with 15 min hold
150/hr >1500F
I use witness cones to verify what the thermocouple reads at end point. I
have a Dawson Kiln Sitter with a ^7 bar as an overfire failsafe to prevent
current going to the coils above that temperature.
I get nice matts with that firing schedule.
nanci
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