Hank Murrow on wed 24 aug 05
On Aug 24, 2005, at 11:33 AM, Les Haworth wrote:
> Can a gas kiln be reduced and still climb in temperature? Does anyone
> have
> oxy probe readings or carbon analysis, which would tell the user that
> the
> kiln atmosphere is in reduction and still climbing?
Dear Les;
My Doorless Fiberkiln uses an OxyProbe (or KilnFinger, as it is known
around here). I get readings of .58 to .64 with the kiln still rising
in temperature during body reduction. Later in the firing, It seems to
be more in reduction with smaller #s. My ultimate guide to reduction is
the color of the flame and whether or not the kiln slows down.
Cheers, Hank
www.murrow.biz/hank
Rikki Gill on wed 24 aug 05
Hi Les,
If you accept the evidence of pyrometer, and eyes, and the color of the ware
afterward, then yes, certainly, the kiln can climb while in heavy reduction.
My carbon trap shino certainly shows evidence of heavy reduction, and I
reduce all the way up. My firing takes twelve hours, which it has always
done, heavy reduction at cone 012 to begin, still in moderate reduction at
the end. I get color I am very pleased with.
Hope this helps
Rikki Gill
www.rikkigillceramics.com
----- Original Message -----
From: "Les Haworth"
To:
Sent: Wednesday, August 24, 2005 11:33 AM
Subject: Reduction question
> Can a gas kiln be reduced and still climb in temperature? Does anyone have
> oxy probe readings or carbon analysis, which would tell the user that the
> kiln atmosphere is in reduction and still climbing?
>
>
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Bob Santerre on wed 24 aug 05
Yes. I use an AIC oxyprobe in a Geil downdraft fiber kiln (40 cu ft
shuttle). The probe is positioned at the entrance to the exit flue. I
can decrease oxygen levels to a reading of .550 on the probe and still
get temperature rise. Above .550 the kiln will stall and even drop
temperature. In my normal firing schedule I typically adjust and hold
the kiln at .450 - .500 when reducing (1700 - 2300 F). This gives about
a 6 ", mildly smokey flame from the top spy hole and the kiln climbs
nicely at about 100 - 150 degrees per hr.
Bob
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
Les Haworth wrote:
>Can a gas kiln be reduced and still climb in temperature? Does anyone have
>oxy probe readings or carbon analysis, which would tell the user that the
>kiln atmosphere is in reduction and still climbing?
>
>______________________________________________________________________________
>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.
>
>
>
>
>
Les Haworth on wed 24 aug 05
Can a gas kiln be reduced and still climb in temperature? Does anyone have
oxy probe readings or carbon analysis, which would tell the user that the
kiln atmosphere is in reduction and still climbing?
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