Don Curtis on mon 2 feb 98
I'm a member of a clay co-op and we use a downdraft gas fired kiln. We have a
very hard time getting this kiln to reduce evenly -especially on the btm and
middle shelves. Also the body reduction tends to be uneven from the front to
back of a pot . Any suggestions on how to solve this problem. Thanks in
advance
Don
In the hills of Western Ma.
jeff walker on tue 3 feb 98
don,
you might try reading Niles Lou's book the are of firing.
very good reading and fires out even too!! the trick seems to be in the
flue arangement.
jeff walker
sedalia, mo
-----Original Message-----
From: Don Curtis
To: Multiple recipients of list CLAYART
Date: Monday, February 02, 1998 9:04 AM
Subject: Poor Reduction-Help
>----------------------------Original message----------------------------
>I'm a member of a clay co-op and we use a downdraft gas fired kiln. We have
a
>very hard time getting this kiln to reduce evenly -especially on the btm
and
>middle shelves. Also the body reduction tends to be uneven from the front
to
>back of a pot . Any suggestions on how to solve this problem. Thanks in
>advance
>
>Don
>In the hills of Western Ma.
>
Craig Martell on tue 3 feb 98
At 09:57 AM 2/2/98 EST, Don wrote:
>----------------------------Original message----------------------------
>I'm a member of a clay co-op and we use a downdraft gas fired kiln. We have a
>very hard time getting this kiln to reduce evenly -especially on the btm and
>middle shelves. Also the body reduction tends to be uneven from the front to
>back of a pot . Any suggestions on how to solve this problem. Thanks in
>advance
Hi Don:
This sounds like the kiln is drawing too hard, too much, too fast. You
might need to reduce the size of the exit flue, or reduce stack height to
lessen the velocity of exiting gasses. The symptoms seem to indicate this.
Also, when the kiln is in reduction with the damper closed a bit, do you get
back pressure and flame from the bottom spy? If you don't, and there is
flame exiting the top spy, this would indicate a hard, fast draw too.
You might want to post some specifics about the kiln so people could zero in
a bit more. Stuff like, total cubic feet, stack height, entrance and exit
flue sizes, number of burners and where they are placed, total btu input,
dimensions of the kiln interior, your last blood pressure reading!
just some thoughts, Craig Martell-Oregon
Corinne Null on tue 3 feb 98
Don,
I doubt I can help you, but I am curious if the coop has a manufactured
kiln (if so, by whom) or a homebuilt?
Corinne Null
Bedford, NH
null@mediaone.net
Stephen Mills on tue 3 feb 98
Don,
The regime I followed for many years was to start reduction around the
1000oC mark (^06) and for the first hour reduce heavily enough to keep
the temperature at that point, thus making sure that the reduction got
right into the clay as early as possible and into every corner of the
Kiln. From then on I eased back to a temperature rise of no more than
45oC per hour up to the finish. I then crash cooled to 950oC. This
latter was more than anything to prevent my Tenmuku from over re-
oxidising.
Hope there is something in this that helps.
Steve
Bath
UK
In message , Don Curtis writes
>----------------------------Original message----------------------------
>I'm a member of a clay co-op and we use a downdraft gas fired kiln. We have a
>very hard time getting this kiln to reduce evenly -especially on the btm and
>middle shelves. Also the body reduction tends to be uneven from the front to
>back of a pot . Any suggestions on how to solve this problem. Thanks in
>advance
>
>Don
>In the hills of Western Ma.
>
--
Steve Mills
Bath
UK
home e-mail: stevemills@mudslinger.demon.co.uk
work e-mail: stevemills@bathpotters.demon.co.uk
BPS website: http://www.bathpotters.demon.co.uk
Roger Korn on thu 5 feb 98
All, The Art of Firing is unavailable and out of print. A new edition from
Nils is due in June, I believe, but will NOT include the MFT kiln design.
Contact Nils for more details. I believe he can send you the MFT plans. Try
contacting him at nlou@linfield.edu.
Roger
----------------------------Original message----------------------------
don,
you might try reading Niles Lou's book the are of firing.
very good reading and fires out even too!! the trick seems to be in the
flue arangement.
jeff walker
sedalia, mo
-----Original Message-----
From: Don Curtis
To: Multiple recipients of list CLAYART <>
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