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kiln sitter conundrum

updated thu 25 mar 04

 

Hendrix, Taylor J. on tue 23 mar 04


Howdy y'all:

Even you bleeding hearts that went to NCECA and kissy kissed all week.
Bleh!

No seriously folks.

I've now fired my kiln 4 times and have yet to see a junior cone bend
enough to set off the kiln sitter. I have manuals for both major types
of sitters and have adjusted it to specs. I have yet to see an 03 cone
bend more that about 15 degrees. All my bisquing is to 04 and I have
placed a cone 2 inches from the business end of the sitter twice and had
a perfect bend of the standard cone. Sensing rod and cone supports are
four firings old. Could they be grabbing the cone and not allowing it
to slump? I have not coated the end of the sensing rod or the supports
with kiln wash yet. Anyone think that matters? I know that many
sitters take one cone hotter that the shelf cones and some do not, but I
am at a loss as to why. My kiln so far has been pretty even. The only
other thing that I can think of is that perhaps the tab on the actuator
weight is corroded and grabs the release claw. Does that sound
possible? My claw is actually plastic. I THINK I have it configured
correctly; I pieced the sitter together from two sitters that I had.
Could I have put it together wrong? When I bought a new sensing rod I
didn't know the tube length so I got the middle size. I had to cut the
rod down, but I allowed for the rod to extend a wee smidge past the ends
of the supports.

I guess I need to take some pictures of what I have. What do y'all
think?

I'm glad everyone had a great time at the family reunion and made it
safely home. Now let's get to pottin', people.

Taylor, in Waco

wayneinkeywest on wed 24 mar 04


Taylor:
Glad to see that you're relying on witness cones and brains,
and not the darned kiln sitter. Check your sitter cones/bars.
Are they the same brand as your witness cones?
Yes, it DOES make a difference, though most manufacturers
will deny that.
Also, if you still have your old sensing rod, make darn sure
the new rod is the exact same length as your old one. A smidge
longer or shorter will affect the weight...and your sanity.
Been there, done that. Do all the parts move freely? Have
you followed the instructions you can get online for adjusting your
kiln sitter, and did you use the adjustment disk? All that stuff
matters. My kiln manufacturer sold me a new adjustment disk
for a buck, (I didn't have one) and tossed in a dozen test cones for
free.
You might want to check with your supplier, since most of them
have that stuff readily available, and it's very reasonably priced.
(Less than a 6-pack for sure)
Hope that helps,
Wayne Seidl

I've now fired my kiln 4 times and have yet to see a junior cone
bend
enough to set off the kiln sitter. I have manuals for both major
types
of sitters and have adjusted it to specs. I have yet to see an 03
cone
bend more that about 15 degrees. All my bisquing is to 04 and I
have
placed a cone 2 inches from the business end of the sitter twice and
had
a perfect bend of the standard cone. Sensing rod and cone supports
are
four firings old. Could they be grabbing the cone and not allowing
it
to slump? I have not coated the end of the sensing rod or the
supports
with kiln wash yet. Anyone think that matters? I know that many
sitters take one cone hotter that the shelf cones and some do not,
but I
am at a loss as to why. My kiln so far has been pretty even. The
only
other thing that I can think of is that perhaps the tab on the
actuator
weight is corroded and grabs the release claw. Does that sound
possible? My claw is actually plastic. I THINK I have it
configured
correctly; I pieced the sitter together from two sitters that I had.
Could I have put it together wrong? When I bought a new sensing rod
I
didn't know the tube length so I got the middle size. I had to cut
the
rod down, but I allowed for the rod to extend a wee smidge past the
ends
of the supports.

I guess I need to take some pictures of what I have. What do y'all
think?

Arnold Howard on wed 24 mar 04


Taylor, does the Kiln Sitter actuating rod move freely within the porcelain
tube? It may be sticking.

Sincerely,

Arnold Howard
Paragon Industries, L.P.
arnoldhoward@att.net

----- Original Message -----
From: "Hendrix, Taylor J."
I've now fired my kiln 4 times and have yet to see a junior cone bend
enough to set off the kiln sitter. I have manuals for both major types
of sitters and have adjusted it to specs. I have yet to see an 03 cone
bend more that about 15 degrees. Taylor, in Waco

Snail Scott on wed 24 mar 04


At 10:05 PM 3/23/04 -0600, Taylor wrote:
>I've now fired my kiln 4 times and have yet to see a junior cone bend
>enough to set off the kiln sitter. I have yet to see an 03 cone
>bend more that about 15 degrees. All my bisquing is to 04...


Is this a problem? It sounds like a Good
Thing to me. Does a ^04 trigger the sitter?

Every sitter, it seems, calibrates slightly
differently, and some need a higher cone in
order to shut off at the point when the witness
cone says to. But the usual reason for putting
a higher cone in the sitter is to prevent it
from shutting off, thus allowing for a manual
shut-down based on the witness cone readings,
letting the sitter act as a fail-safe only.

In either case, a ^03 failing to trigger the
sitter for a ^04 firing seems like near-
perfect calibration to me. I know you know this
stuff, though. Do I misunderstand the question?

-Snail

Brad Sondahl on wed 24 mar 04


I think you are justifiably confused as to cones with the 0 designation.
Cone 03 is hotter than cone 04, so it isn't likely to bend when the
kiln shuts off with a Cone 04 in the sitter. The cones with a 0 before
them get hotter as they count down to one. Then the cones without a zero
go up from 1 to 12 or 14 or whatever. You can try making a cone pack
(out of clay) with a series of cones in a line, to see what temperature
your bisque is actually firing to. By the way, although clays vary,
cone 04 is hot to my thinking for a bisque. If you have trouble
absorbing glaze onto your wares, try cone 05 or 06.
Brad Sondahl

--
For original art, music, pottery, and literature, visit my homepage
http://sondahl.com

Hendrix, Taylor J. on wed 24 mar 04


Not a problem really. I watch the cones bend anyway, but I sure would
like to know why the junior cone bends so little. I would have expected
it to bend more than it does. Next bisque I plan to put in an 04 to
see. I'll wash the contact points too. Keep forgetting that.

See no problem, just conundrum.

Taylor, in Waco

-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG] On Behalf Of Snail Scott
Sent: Wednesday, March 24, 2004 9:38 AM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Re: Kiln sitter conundrum


At 10:05 PM 3/23/04 -0600, Taylor wrote:
>I've now fired my kiln 4 times and have yet to see a junior cone bend
>enough to set off the kiln sitter. I have yet to see an 03 cone
>bend more that about 15 degrees. All my bisquing is to 04...


Is this a problem? It sounds like a Good
Thing to me. Does a ^04 trigger the sitter?

...

In either case, a ^03 failing to trigger the
sitter for a ^04 firing seems like near-
perfect calibration to me. I know you know this
stuff, though. Do I misunderstand the question?
...