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de-lurking for kiln help

updated wed 7 jan 04

 

Ed Tackett on sun 4 jan 04


Ok.

I have a shiny "new" used kiln CRESS FTX-23 P. Got it wired, installed =
=3D
my L & L Kiln Vent calibrated it.

Now for the big question it has a kiln sitter and several other features =
=3D
but the guide dosent exactly tell you how to fire things.

I know that if Im firing to ^06 I need to put a junior ^06 in the kiln =
=3D
sitter. But on the witness cones do I put up a ^05 and ^06 or ^06 and =
=3D
^07 ?

How do I know how to set up the fire time on the dial ?

Doese anyone else have one of these ?

TIA

Ed

Snail Scott on mon 5 jan 04


At 04:22 PM 1/5/04 -0600, you wrote:
>...How to fire
>it with the kiln sitter, the timers, and still use my witness cones for
>accuracy. In my old Crusader, I aways watched the cones go down, and
>when they were bent just right, I would manually shut off the kiln...


No need to change; you can fire the Paragon
the same way. Just put in a sitter cone that's
higher than you intend to fire - it's still there
as a failsafe, but it won't shut it off before
you decide to. And just set the timer to more
time than you think you'll need. I wouldn't run
it all the way to maximum; just an hour or two
past what you think you might need. If you want
more time, just crank it back a few hours. It's
there to prevent catastrophe if you get called
away unexpectedly and can't shut it down yourself,
so you might as well take advantage of its
presence, but it needn't alter your firing habits
in any way. Just keep using those witness cones,
shutting down manually like always, and enjoy the
peace of mind of a dual-failsafe backup that you
will (I hope) never need.

-Snail

claybair on mon 5 jan 04


Hi Ed,

If you have a Dawson Kiln sitter you should have
an instruction booklet... if not try www.kiln-sitter.com

My kiln has an electronic controller so the Kiln sitter is a back up
safety feature. I don't know whether your kiln has a electronic controller
so I do not know if my experience will be helpful.

I usually put a higher cone in the kiln sitter e.g. if
firing to ^6 I put a ^7cone in the sitter.
I found that sometimes a soak at the end of the firing will
bend the small cone and shut the kiln down prematurely.
All I want the kiln sitter to do is prevent an accidental over firing.

Once you get the "feel" of you kiln and claybody you will be able
to adjust the cones to you desired firings.
I believe I have taken my clay (Laguna ^5 B-Mix) to ^7
as the witness cone 6 was pretty much laying on the kiln shelf
and the cone in the sitter was u shaped. It was a good firing
and the fact that I had a higher cone in the sitter prevented
overfiring and underfiring.
FYI I have had my kiln for 7 years and just recently have I had
near perfect firings.... but I am sloooow... you will likely have a much
faster learning curve.

Regarding witness cones I personally don't bother with 3 of them.
I use only one (the ^ I am firing to) and depending on the angle
I can determine whether it fired too high or low or to temperature.
I place one on each shelf except when the shelves are too close and
the cone won't fit.

Fire time on the dial... I keep it cranked all the way up.
It's a timer... early in my kiln experience I turned it up to 8 hours...
and of course it shut down my kiln before the firing was completed.
When my controller is on after the firing I can see the rate of cool
down.

Good luck and happy firings!

Gayle Bair
Bainbridge Island, WA
http://claybair.com

-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG]On Behalf Of Ed Tackett
Sent: Sunday, January 04, 2004 8:12 PM
To: CLAYART@LSV.CERAMICS.ORG
Subject: De-lurking for kiln help


Ok.

I have a shiny "new" used kiln CRESS FTX-23 P. Got it wired, installed =
my L & L Kiln Vent calibrated it.

Now for the big question it has a kiln sitter and several other features =
but the guide dosent exactly tell you how to fire things.

I know that if Im firing to ^06 I need to put a junior ^06 in the kiln =
sitter. But on the witness cones do I put up a ^05 and ^06 or ^06 and =
^07 ?

How do I know how to set up the fire time on the dial ?

Doese anyone else have one of these ?

TIA

Ed

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melpots@pclink.com.

Snail Scott on mon 5 jan 04


At 08:12 PM 1/4/04 -0800, Ed wrote:
>I know that if Im firing to ^06 I need to put a junior ^06 in the kiln =
>sitter. But on the witness cones do I put up a ^05 and ^06 or ^06 and =
>^07 ?
>How do I know how to set up the fire time on the dial ?


I prefer to put a higher cone in the sitter, and
NOT to rely on the sitter to shut it off. I use
the witness cones to tell me that. Kiln sitters
are terrific fail-safe devices, but I'd rather
not trust them to do the decision-making. So, if
I were shooting for ^06, I'd put a ^05 in the
sitter and a ^07, ^06 and ^05 in the witness-cone
pack. The first cone, the lowest, is called a
'guide cone'and if you have room to see them,
you can use several, to help you gauge the speed
of your firing. The ^06 in this case is your
'firing cone'. It will tell you exactly when you
should shut down the kiln. The ^05 is your
'guard cone', to tell you when you are about to
overshoot your mark. Use the sitter as a fail-safe,
in case you get hit by a bus, but use your eyes to
choose when to shut off the kiln, if precise
results matter. (I do use my sitter to shut off my
bisque, since I don't much care about the exact
temperature, but for glaze firings, I'd rather
be in control.)

Also, witness cones and sitter cones seldom agree.
Once you fire with witness cones and compare the
result with your sitter cone, you may decide that
you need to recalibrate your sitter, or (as I do)
just put a different cone in to suit your purposes.
With my kiln, for example a ^6 witness cone equals
a ^7 sitter cone, so I put a ^8 in the sitter so
it won't shut off too soon, and I turn it off (or
down for a slow cool) when the ^6 witness cone
bends.

Your mileage may vary. But in general, use three
witness cones: one for your intended firing temp,
plus at least one each above and below that temp.
Even if you choose to let your sitter shut the
kiln off for you, having several cone packs
scattered about the kiln will tell you how hot
the kiln really got, and how evenly it is firing.

As for the timer: At first, just crank it all the
way around. After a few (supervised!) firings,
you will know how long a firing should take. Then,
set the timer for about an hour longer than a
firing should take. Then if the sitter fails, it
won't get so much hotter that a meltdown could
occur. Like the sitter itself, it functions best
as a backup or fail-safe.

-Snail

John Rodgers on mon 5 jan 04


I have in the past used many kilns with the Dawson Kiln Sitter. But in
the last several years I have been doing my firings in an Old Crusader
kiln that has no kiln sitter. As a matter of fact, the only controls at
all are infinity switches that are marked from Off to Hi with 9 steps in
between. The "HI" position is step 10. I have found over time that I get
excellent results using the free standing witness cones in the Crusader.
The Crusader and the witness cones give me perfect Floating Blue every
time. I doubt I could do that with the Kiln Sitter. I have a brand new
Paragon SnF I "acquired", and it is posing me a diliema ... How to fire
it with the kiln sitter, the timers, and still use my witness cones for
accuracy. In my old Crusader, I aways watched the cones go down, and
when they were bent just right, I would manually shut off the kiln.
There are so many controls and gadgets on this new Paragon, that I'm a
bit overwhelmed. I really liked the simplicity of firing the Crusader.
Set the cones, close the lid, set the switches and let her rip. As she
approached temperature, begin watching the cones. When the cone went
doen, turn it off manually. Can't get much simpler than that. Beautiful
pots. Can't be beat. But the Crusader is old, old, old. About 42 years
to be exact. I guess I will just have to learn how to use the new SnF in
spite of myself. Probably waste a bunch of pots on the new learning
curve though.

Oh, Well!

Regards,

John Rodgers
Chelsea, AL

claybair wrote:

>Hi Ed,
>
>If you have a Dawson Kiln sitter you should have
>an instruction booklet... if not try www.kiln-sitter.com
>
>My kiln has an electronic controller so the Kiln sitter is a back up
>safety feature. I don't know whether your kiln has a electronic controller
>so I do not know if my experience will be helpful.
>
>I usually put a higher cone in the kiln sitter e.g. if
>firing to ^6 I put a ^7cone in the sitter.
>I found that sometimes a soak at the end of the firing will
>bend the small cone and shut the kiln down prematurely.
>All I want the kiln sitter to do is prevent an accidental over firing.
>
>Once you get the "feel" of you kiln and claybody you will be able
>to adjust the cones to you desired firings.
>I believe I have taken my clay (Laguna ^5 B-Mix) to ^7
>as the witness cone 6 was pretty much laying on the kiln shelf
>and the cone in the sitter was u shaped. It was a good firing
>and the fact that I had a higher cone in the sitter prevented
>overfiring and underfiring.
>FYI I have had my kiln for 7 years and just recently have I had
>near perfect firings.... but I am sloooow... you will likely have a much
>faster learning curve.
>
>Regarding witness cones I personally don't bother with 3 of them.
>I use only one (the ^ I am firing to) and depending on the angle
>I can determine whether it fired too high or low or to temperature.
>I place one on each shelf except when the shelves are too close and
>the cone won't fit.
>
>Fire time on the dial... I keep it cranked all the way up.
>It's a timer... early in my kiln experience I turned it up to 8 hours...
>and of course it shut down my kiln before the firing was completed.
>When my controller is on after the firing I can see the rate of cool
>down.
>
>Good luck and happy firings!
>
>Gayle Bair
>Bainbridge Island, WA
>http://claybair.com
>
>-----Original Message-----
>From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG]On Behalf Of Ed Tackett
>Sent: Sunday, January 04, 2004 8:12 PM
>To: CLAYART@LSV.CERAMICS.ORG
>Subject: De-lurking for kiln help
>
>
>Ok.
>
>I have a shiny "new" used kiln CRESS FTX-23 P. Got it wired, installed =
>my L & L Kiln Vent calibrated it.
>
>Now for the big question it has a kiln sitter and several other features =
>but the guide dosent exactly tell you how to fire things.
>
>I know that if Im firing to ^06 I need to put a junior ^06 in the kiln =
>sitter. But on the witness cones do I put up a ^05 and ^06 or ^06 and =
>^07 ?
>
>How do I know how to set up the fire time on the dial ?
>
>Doese anyone else have one of these ?
>
>TIA
>
>Ed
>
>____________________________________________________________________________
>__
>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.
>
>______________________________________________________________________________
>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.
>
>
>

Ian Smith on mon 5 jan 04


I may not be able to add much to the excellent responses to this query, but
here are a few observations re: kiln sitter from my kilns:

1. Like others who responded, I use the kiln sitter primarily as a safety
feature, and use a small cone one cone higher than desired firing temp.
2. I also observe a discrepancy between the small cones in the kiln sitter
mechanism and the large witness cones. I simply factor that in.
3. I always use three cones for a glaze firing. If, for example, I wish to
soak at peak temp for 20 minutes, I might begin the soak when the first cone
goes down. Similarly if I intend to cool slowly.
4. It is important to keep records of each firing. Such records of settings,
times, outcomes will help in the future. These records will also allow you
to track changes as the elements in the kiln age.
5. You might consider buying a pyrometer. Easy to install. Allows you to
chart the progress of your firings, and, more importantly, cool at a
prespecified rate.
6. Finally, you might consider a computer controller. If you are handy, you
can build a nice one for under $200 (www.bartinst.com). The great advantage
of a controller is that it permits a more controlled cooling than I can
accomplish manually. I find this very important for mattes in which I wish
to encourage some crystal growth.

Good luck.

Snail Scott on tue 6 jan 04


John R.-

Sorry; I missed the SnF designation regarding
your kiln. Please disregard my totally irrelevant
previous suggestions!

-Snail