Caleb Long on thu 20 may 99
We need to fire a Skutt KM-1227 to cone 10 until we can get
our gas kiln built. I know your not asupposed to do this, element
and refractory wear etc., but we need to so... I have fired other
2300 rated kilns up to cone 10 by the cone but the automatic
controller is kind of a new deal for us. The question is does
anyone have a firing schedule to get this thing to cone 10. The
issue of course is rate of temperature increase versus heat work.
Will the auto program work? (personally I doubt it) Can this Kiln,
on a 208 3-phase service, maintain 108/hr between cone 8 and
cone 10 so I can program the end temperature? Do I just have to
babysit a cone firing to manually determine the actual endpoint
temperature/heatwork correspondence? Has anyone done this
already?
The second question is: Is it possible to rewire this kiln with a
stouter element so that it can take cone 10 regularly without
replacing them all the time?
Thanks,
Rob
Robert Reeve
Warsaw, MO
rob
Euclids on sat 22 may 99
Hi Caleb,
As far as i know, the Skutt KM 1227 is only a cone 8 kiln (48 amps on 240
volts). For a 10 cubic foot kiln to be rated cone 10, you will need 60 amps
on 240 volts.
You can put in more powerful elements but you will need to make sure that
the kiln & its components can handle the extra power. You may have to
install more relays, increase the capacity of the supply cable & possibly
the supply wires to the elements.
Chris @
Euclids Kilns & Elements
1-800-296-5456
euclids.com
mail@euclids.com
Eleanor Arkowitz on thu 15 jun 06
i am sorry to ask this but i can't find any
reference to it in the archives. i think that i
read, just in the last few months, of a new firing
schedule for ^6 oxidation. i have been using the
old one in john and ron's book and i think that
there has been an update. if anyone has it could
they post it either to the list or to me
personally.
thanks.
eleanor arkowitz in hanover n.h. where it is
finally sunny and warm
John and Judy Hesselberth on thu 15 jun 06
On Jun 15, 2006, at 11:03 AM, Eleanor Arkowitz wrote:
> i have been using the
> old one in john and ron's book and i think that
> there has been an update. if anyone has it could
> they post it either to the list or to me
> personally.
Hi Eleanor,
You can find it at:
http://masteringglazes.com/Pages/faqframe.html
It is not much different. It just drops the temperature away from
peak (after the soak) down to about 1900F. Nothing much happens in
this zone and it might prolong your elements and will save a little
energy. Then we slow cool from 1900 down to 1400F.
Regards,
John
Gene & Dolita Dohrman on thu 15 jun 06
SLOW GLAZE PROGRAM
My firing takes about 12 hours to reach temperature. I can start it at 9:00
pm at night and be sure I am out in the studio at around 8:30 the next
morning. Then I watch the cones closely. I usually start checking when the
thermocouples read 2130°. It seems I am always tweaking it. I really like
what this does to mattes and I get nice small crystal growth in glossies
too.
Segment 1 60°/hr 210° Hold for 1-2 hours
I usually load the kiln right after glazing or even as I am glazing, so the
ware is fairly wet.
Segment 2 250°/hr 2000°
Segment 3 60°/hr 2150° This may vary depending on your kiln load. Hold
till ^6 is where you want it but I don't like to soak longer than 30
minutes. Turn off vent.
Segment 4 150°/hr 1800° Hold 30 minutes
Segment 5 100°/hr 1400°
--
No virus found in this outgoing message.
Checked by AVG Free Edition.
Version: 7.1.392 / Virus Database: 268.8.4/364 - Release Date: 6/14/06
Gene & Dolita Dohrman on fri 16 jun 06
SLOW GLAZE PROGRAM
My firing takes about 12 hours to reach temperature. I can start it at =
9:00
pm at night and be sure I am out in the studio at around 8:30 the next
morning. Then I watch the cones closely. I usually start checking when =
the
thermocouples read 2130=B0. It seems I am always tweaking it. I really =
like
what this does to mattes and I get nice small crystal growth in glossies
too.
Segment 1 60=B0/hr 210=B0 Hold for 1-2 hours
I usually load the kiln right after glazing or even as I am glazing, so =
the
ware is fairly wet.
Segment 2 250=B0/hr 2000=B0
Segment 3 60=B0/hr 2150=B0 This may vary depending on your kiln =
load. Hold
till ^6 is where you want it but I don't like to soak longer than 30
minutes. Turn off vent.
Segment 4 150=B0/hr 1800=B0 Hold 30 minutes
Segment 5 100=B0/hr 1400=B0
Dolita
earlk on sat 17 jun 06
On Fri, 2006-06-16 at 22:09 -0400, Gene & Dolita Dohrman wrote:
> Segment 1 60=B0/hr 210=B0 Hold for 1-2 hours
> I usually load the kiln right after glazing or even as I am glazing=
,
> so the
> ware is fairly wet.
I thought Dolita's schedule was interesting
since in drying out her ware she raises the
temperature above the boiling point of water
and then holds for a while.
I always raise the temperature to just below
the boiling point and then hold in order not
to have any steam explosions that would=20
destroy the pot or blow off a piece of glaze.
Boiling occurs whenever the vapour pressure=20
of water exceeds the pressure in the water,=20
which is close to atmospheric pressure except=20
at the bottom of a deep vessel. I searched the=20
Internet for a graph of vapor pressure vs=20
temperature for water and found this:
http://hyperphysics.phy-astr.gsu.edu/hbase/kinetic/watvap.html#c2
As you can see the vapor pressure rises quickly
as you approach the normal atmospheric boiling=20
point. Since evaporation is in direct proportion to
the vapour pressure you can achieve almost as=20
good an evaporation rate just below the boiling
point as above it without risking a steam explosion.
Of course, as Ivor is liable to point out, this does
not take into account factors such as the binding
strength of a water molecule to a clay particle
which I will leave for another discussion.
=20
earlk...
bothell, wa, usa
=20
Ivor and Olive Lewis on sun 18 jun 06
Dear Earl k,=20
No need to dispute your reasoning. But do not forget the effects of =
Relative Humidity of the local atmosphere or Altitude on Boiling point..
I note that if you decrease vapour pressure by a half boiling =
temperature decreases by about 20 degrees C. My old physics teacher =
demonstrated this to us. As pressure drops the release of steam from the =
water has explosive force. This is countered by putting a bit of brick =
in with the water to give points at which bubble growth can nucleate.
Best regards,
Ivor
| |
|
