Keep the kiln lid or door closed when the kiln is not in use. 17
Suppose you enter a cooling rate that is faster than the
kiln can cool? Depending on the rate you enter, you may get
an alarm message. (Press ENTER to turn off the alarm.)
The controller, of course, cannot speed cooling
beyond the kiln’s natural cooling rate.
Temperature Overshoot
When a kiln is heated too fast, it may overshoot the tar
-
get temperature, especially in small kilns at lower tempera
-
tures. To avoid this, add an extra segment to slow the firing.
The segment with the slower rate should begin about 40° -
60° below the target temperature of the following segment.
A Practice Program
To practice using the controller, we will enter a program
that includes three segments. The last segment is a cooling
segment.
Using the instructions in the red box on page 15, enter
this firing schedule. Then use Program Review to check for
accuracy.
USER = 1
RA1 = 250
°F1=750
HD 1 = 00.00
RA2 = 900
°F 2 = 1425
HD 2 = 00.30
RA3 = 150
°F3=750
HD 3 = 00.00
RA4 = 0
Note: Enter 0 for the rate in segment 4. This zeroes
out all the segments past segment 3.
Sample Firing Schedules
These sample firing schedules illustrate different ways to
program the Sentry. When designing a firing schedule for
materials you are unfamiliar with, or when using one of
these schedules, always test-fire samples first. This is be
-
cause these generalized schedules may not suit the clay or
glass that you use.
For practice, you might want to enter these programs
even though you may never actually use them.
Cone-Fire Program Customized
in Ramp-Hold
This is the cone 04 Cone-Fire schedule at standard
(Medium) speed with an added slow-cooling segment. (See
Cone-Fire schedules on pages 32 - 33.)
Rate Temp.
Segment °F/°C °F/°C Hold
1 324/180 1022/550 00.00
2 153/85 1112/600 00.00
3 180/100 1837/1003 00.00
4 108/60 1945/1063 00.00
5 150/83 1000/537 00.00
In this schedule, the kiln will cool at 150°F/83°C per hour
to 1000°F/537°C. Some ceramists use slow cooling to
enhance certain glazes.
Sculptured Stoneware Bisque Firing
Schedule, Cone 04
Rate Temp.
Segment °F/°C °F/°C Hold
1 60/33 200/93 03.00
2 80/44 700/371 02.00
3 80/44 1100/593 00.00
4 108/60 1945/1062 00.00
5 150/83 1400/760 00.00
This slow firing is for thick stoneware. Change the target
temperature in segment 4 when firing to a different pyro-
metric cone. The ware should be bone dry. Test samples un-
til you are sure the schedule works for your ware.
If you are not using a kiln vent, leave peephole plugs out
and prop the lid in the vented position. Set the alarm to
1000°F/537°C. When the alarm sounds, close the lid from
the venting position.
Set the alarm again, this time to 1850°F/1010°C. When it
sounds, check the witness cone through a peephole. When
the cone bends to six o’clock, write down the temperature.
(Use that temperature in segment 4 on your next firing of
the same type of ware.) Then press 9, ENTER (Skip Seg
-
ment).
This will advance you to segment 5, a slow cooling seg
-
ment. Do not open the lid until the kiln has cooled to room
temperature.
Glass Fusing Firing Schedule
Rate Temp.
Segment °F / °C °F / °C Hold
1 250 / 138 750 / 398 00.00
2 900 / 500 1425 / 773 00.30
3 9999 / 9999 1050 / 565 00.00
4 150 / 83 750 / 398 00.00
Stained glass,
1
8
", 2 layers, full fuse. The fusing tempera
-
ture will vary depending on the brand of glass, the batch,
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