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cutting down shelves

updated wed 7 aug 02

 

Ron & Nancy on fri 2 aug 02


Hi guys,
Would like to get an opinion from some of you who might know. I put
together a kiln from old kiln parts, It is a propane,10 side, skutt style
updraft. I have been having a horrific time trying to even out my cones. =
The
bottom is always a cone to 2 cones higher than the top. I have warped 2 n=
ew
1 inch thick shelves in 5 firings. I am firing to cone 10.=20
It was suggested to me to cut my shelves down an inch,( there is now
about =BE of an inch distance between the kiln wall and the shelf) to get
better air flow (more even air flow) . Ok here comes my doubt....... The
last firing only one side of the kiln was shelves the other side was tall
sculptures. In my way of thinking, this configuration should have evened =
out
the kiln heat, if it was a lack of air flow. The cones max on the bottom
at^11 and the top was barely moving at^ 9.
Cutting down shelves is doable if that is what is needed. But I
would rather not if there is another way. It was also suggested that I no=
t
put a bag wall (I use shelves) on top. But instead stilt a piece of a she=
lve
under the lid (about two inches away.) any thoughts on the subject?
I would just try it but if it's wrong...??? It's like cutting the
door to short ya know I mean?
Thank you for the help.
Nancy
=09

ranmcc on sat 3 aug 02


I was told that to even out the heat temperature on my updraft to stilt at
least an 18 inch baffle under the top port 3 inches from the lid. They said
it was a key in getting even heat through out the kiln. My shelves are at
least one inch from the sides of the kiln. I will be firing it in the next
couple of weeks so I will let folks know how it goes. If you get the top
baffle any lower it can cause the kiln to stall.

Those have been suggestions given to me.


----- Original Message -----
From: "Ron & Nancy"
To:
Sent: Saturday, August 03, 2002 12:15 AM
Subject: Cutting down shelves


Hi guys,
Would like to get an opinion from some of you who might know. I put
together a kiln from old kiln parts, It is a propane,10 side, skutt style
updraft. I have been having a horrific time trying to even out my cones. The
bottom is always a cone to 2 cones higher than the top. I have warped 2 new
1 inch thick shelves in 5 firings. I am firing to cone 10.
It was suggested to me to cut my shelves down an inch,( there is now
about of an inch distance between the kiln wall and the shelf) to get
better air flow (more even air flow) . Ok here comes my doubt....... The
last firing only one side of the kiln was shelves the other side was tall
sculptures. In my way of thinking, this configuration should have evened out
the kiln heat, if it was a lack of air flow. The cones max on the bottom
at^11 and the top was barely moving at^ 9.
Cutting down shelves is doable if that is what is needed. But I
would rather not if there is another way. It was also suggested that I not
put a bag wall (I use shelves) on top. But instead stilt a piece of a shelve
under the lid (about two inches away.) any thoughts on the subject?
I would just try it but if it's wrong...??? It's like cutting the
door to short ya know I mean?
Thank you for the help.
Nancy


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Mike Gordon on sat 3 aug 02


Hi,
I fire an Alpine updraft and the burners come through the floor on each
side which takes up about 4" of space for the flame. My shelves are at
least 2" shorter on each side of that leaving about 6" of space between
the wall and the shelf. I'm not familiar with a Skutt updraft but 1" on
each side seems too tight to me. Mike Gordon

Snail Scott on tue 6 aug 02


At 09:15 PM 8/2/02 -0700, you wrote:
> I put
>together a kiln from old kiln parts, It is a propane,10 side, skutt style
>updraft. I have been having a horrific time trying to even out my cones. The
>bottom is always a cone to 2 cones higher than the top.


One possibility: If you have a lot of heat at the bottom,
but it's just rushing out the top without obstruction,
closing the damper a bit can help hold heat at the top.
Using a top shelf with no ware on it can serve a similar
purpose, too, if there's room in the kiln.

Damper and airflow can be tricky things, especially
if the chimney-hole is small. But, if you get your
damper set just right, you get better heat rise with
less fuel consumption. If you have access to a
pyrometer, you can watch the effect of each adjustment
in real time. If you don't have one, you can still
watch the color change inside the kiln. You just
won't get the information as quickly or precisely.

-Snail