EASLEY on sat 12 jan 02
There is a website for these, and they have detailed info and instructions
on adjusting them. I think your friend’s problem can probably be taken care
of to a large degree (pun definitely meant) by re-adjusting the cone holder.
Pam in Seattle
Karin Abromaitis on sat 12 jan 02
I think there must be some way to calibrate/ adjust a kiln sitter to matc=
h the cone. A friend of mine has an electric kiln (used, but new to her)=
. She said that the kiln is firing much hotter than the sitter cone. Sh=
e's estimating that a cone 5 sitter cone is not shutting off the kiln unt=
il about cone 8. Any suggestions would be appreciated. Couldn't find th=
is on the archives. Thanks.
Karin A.
potterybydai on sat 12 jan 02
Hi, Karin - you can get a little metal disk that is a gauge for kiln sitters
to see if your "drop" thing on the outside is too high or too low---they
come with instructions on how to use them, and should be available from a
pottery supply place. I've found that the fired cone should have about a
90 degree bend in it. BUT...you're going to hear from all the clayarters
who never rely on a sitter, and will tell you to use large cones in a cone
pack, and I agree that's the only way to really tell what cone it fires to,
and each shelf may be different.
Anyway, I think if your friend's kiln is firing to ^8 with a ^5 in the
sitter, the cone would be just about drooled off the supports by that time.
And the clay would probably be bloated, unless it's rated at much higher
than ^5. Is that what's happening?
Dai in Kelowna, BC
potterybydai@shaw.ca
"Never put off until tomorrow that which can be avoided altogether."
attributed to Ann Landers
----- Original Message -----
From: "Karin Abromaitis"
To:
Sent: Saturday, January 12, 2002 1:04 PM
Subject: [CLAYART] calibrating kiln sitters
I think there must be some way to calibrate/ adjust a kiln sitter to match
the cone. A friend of mine has an electric kiln (used, but new to her).
She said that the kiln is firing much hotter than the sitter cone. She's
estimating that a cone 5 sitter cone is not shutting off the kiln until
about cone 8. Any suggestions would be appreciated. Couldn't find this on
the archives. Thanks.
Karin A.
william schran on sat 12 jan 02
Karin - If you or your friend don't still have the instruction book &
adjustment gauge that came with the kiln/sitter, then go online to
Orton and get them. The sitter needs to be checked for adjustment,
but more importantly, you should not use the sitter to fire the kiln,
use witness cones, then you won't have to guess.
Bill
Snail Scott on sat 12 jan 02
At 04:04 PM 1/12/02 -0500, Karin wrote:
>I think there must be some way to calibrate/ adjust a kiln sitter to match
the cone... a cone 5 sitter cone is not shutting off the kiln until about
cone 8...
There is stuff in the archives, but here's the basics.
The adjustment is on the deadfall of the sitter. (The=20
'flap' that drops when it turns off.) A little set-screw
holds a flat metal tab in place. (That's the tab that=20
catches unter the 'hook' when you set the thing.)=20
Put a bit of tape on the tab, to keep it from sliding=20
all over when you mess with it. Then use a small=20
screwdriver to loosen the set-screw. Then slide the=20
tab in (so it doesn't stick out so far) and tighten=20
the set-screw to hold it there.
You can get a little template from many suppliers=20
which will set the position exactly, but it can be=20
done pretty closely by eye. Just be sure to closely=20
monitor the next few firings and readjust as needed=20
to get the right position.
In theory, a properly adjusted sitter will shut off=20
when the cone is bent to 90=BA. If the tab sticks out=20
too far, the cone will have to bend further before=20
the deadfall is released, and the kiln will get too=20
hot. If the tab is not extended far enough, the cone=20
will only have to bend a little before the deadfall=20
is released, shutting the kiln off too soon.=20
Of course, you can adjust your own sitter however you=20
like. Messing with the tab can allow a certain amount=20
of 'fine-tuning' the shutoff temperature, higher or=20
lower than the nominal cone rating.
Remember, though, that a witness cone will always read=20
a little differently than a sitter cone, and is almost=20
always a more reliable indicator of firing temperature=20
heat-work, actually) than the sitter or a pyrometer.
-Snail
Valice Raffi on sat 12 jan 02
Karen,
here is a post from John Hesselberth (May 2001) that I'd saved that
describes the process.
Valice
in Sacramento
John's post:
Don't know if I can do this without being able to sketch it or not, but
I'll try. There are two adjustments to be made on the front of the sitter.
You need a small alan (hex) wrench to loosen the set screws.
First, though, you have to slip the little calibration gauge/bracket, that
came with the sitter, over the prongs (on which the cone sits) and the rod
(which sits on the cone). If you don't have one of these, most pottery
supply stores carry them. They can't (or maybe I should say shouldn't) cost
more than a dollar or so.
Second when you hold the trip lever in the up position pushed back toward
the kiln as far as it will go, there should be 1/16" clearance (front to
back or horizontal clearance) between it and the L shaped hook that sits
and "hooks" over it. You adjust this by loosening the set screw on the L
shaped hook and sliding it one way or the other. Then retighten.
Third, you adjust the clearance between the L shaped hook and the trip
lever so the trip lever just clears the L shaped hook when the calibration
gauge is in place. The set screw to do this is on the trip lever.
Retighten both set screws, remove the calibration gauge and you're done. If
this isn't clear maybe someone else can do a better job of describing it to
you.
Regards, John
FireRight on sat 12 jan 02
Reminder: http://www.kilnsitter.com offers downloadable instruction books
which include illustrated calibration procedures, tips and hints, and so on.
-=gw=-
----- Original Message -----
From: "Karin Abromaitis"
To:
Sent: Saturday, January 12, 2002 4:04 PM
Subject: calibrating kiln sitters
I think there must be some way to calibrate/ adjust a kiln sitter to match
the cone. A friend of mine has an electric kiln (used, but new to her).
She said that the kiln is firing much hotter than the sitter cone. She's
estimating that a cone 5 sitter cone is not shutting off the kiln until
about cone 8. Any suggestions would be appreciated. Couldn't find this on
the archives. Thanks.
Karin A.
____________________________________________________________________________
__
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Moderator of the list is Mel Jacobson who may be reached at
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Tommy Humphries on sat 12 jan 02
There is a set-screw on the shut off weight that can be loosened to adjust
the tab that the shut off rod hooks over, in the case of needing to lower
the shut off temp. you should shorten the tab a bit... You can get a
calibration from the folks at kiln sitter, or from most supply houses, that
fits over the cone supports and the shut off rod inside the kiln. The weight
should be adjusted so that it just slips past the rod when this is in place.
Tommy
----- Original Message -----
From: "Karin Abromaitis"
To:
Sent: Saturday, January 12, 2002 3:04 PM
Subject: calibrating kiln sitters
I think there must be some way to calibrate/ adjust a kiln sitter to match
the cone. A friend of mine has an electric kiln (used, but new to her).
She said that the kiln is firing much hotter than the sitter cone. She's
estimating that a cone 5 sitter cone is not shutting off the kiln until
about cone 8. Any suggestions would be appreciated. Couldn't find this on
the archives. Thanks.
Karin A.
____________________________________________________________________________
__
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.
Frederich, Tim on mon 14 jan 02
Karin,
kiln-sitters often tend to vary from what is happening on the shelf, but
usually not by as much as you have said. The kiln-sitter probably needs to
be maintained or replaced. I would suggest that it be serviced by a
responsible kiln repair person. You might inquire at your local supplier for
the person in your area who does kiln repair.
Best regards,
Tim Frederich,
Orton Ceramic Foundation
-----Original Message-----
From: Karin Abromaitis [mailto:Kabromaitis@MSN.COM]
Sent: Saturday, January 12, 2002 4:05 PM
To: CLAYART@LSV.CERAMICS.ORG
Subject: calibrating kiln sitters
I think there must be some way to calibrate/ adjust a kiln sitter to match
the cone. A friend of mine has an electric kiln (used, but new to her).
She said that the kiln is firing much hotter than the sitter cone. She's
estimating that a cone 5 sitter cone is not shutting off the kiln until
about cone 8. Any suggestions would be appreciated. Couldn't find this on
the archives. Thanks.
Karin A.
____________________________________________________________________________
__
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.
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