Sentry Industries Sentry 2.0 - Manual (Page 10)

Mirror Test
This test will help you de-
termine how much Pre-Heat
to use. Occasionally during
Pre-Heat, hold a mirror near
the top peephole. (Be careful
to avoid burns.) The mirror
must be at room tempera-
ture, not hot, so hold it near
the peephole for only several
seconds.
If the mirror fogs, mois-
ture is still escaping from the
ware. When the mirror no longer fogs, you can exit Pre-Heat
and begin the firing.
To interrupt Pre-Heat and begin firing to the cone in
Cone-Fire, press 9(Skip Segment). SKIP , alternating with
1 , will appear. Press ENTER. Segment 1 of the firing will
now begin. (See Cone-Fire firing schedules, page 9.)
Note: If you are using a vent fan, such as the Orton
KilnVent, turn the fan on during Pre-Heat. The fan
will help to remove moisture. (AOP Fan users: see
the Fan option, page 18.)
How to Use Pre-Heat When Kiln is Above
200°F/93°C at Beginning of Firing
If you begin firing with Pre-Heat in a kiln that is already
hotter than Pre-Heat temperature, the kiln will skip
Pre-Heat and begin firing to the cone. There are two ways to
use Pre-Heat in this situation:
■ Wait until the kiln cools below 200°F before starting the
firing. This is the preferred method.
■ Load the kiln and start the firing, but include enough
time in Delay for the kiln to cool below 200°F before
Pre-Heat begins.
Hold (HOLd)
Cone-Fire Hold heat-soaks the ware at the cone tempera-
ture at the end of the firing. Without Hold, the kiln shuts off
after it reaches the cone temperature. Hold maintains the
cone temperature for the period you specify. Hold helps even
out the temperature throughout the kiln. It also helps the
heat to penetrate completely into the clay. (Rapid firing is
like cooking: the turkey will be done on the outside but not
on the inside.) Hold helps glaze absorb china paint. It helps
to heal glaze defects such as bubbles. A little hold time can
yield dramatic results.
CAUTION: Too much hold time can overfire your
ware and burn out colors.
One way to add Hold time without over-firing is to fire to
one cone cooler than needed. Then add enough hold time to
bend the next hotter cone. Hold time needed to bend the
next cone will vary. As a rule of thumb, 45 - 60 minutes of
hold = one cone of heat work.
Example: to fire to cone 05, program Cone-Fire for 06
and add 45-60 minutes of hold time.
10
Cone-Fire Programming
Use these instructions for your first firings. Later
you may prefer “Cone-Fire Shorthand Pro-
gramming,” page 32.
As the Sentry prompts for cone, speed, pre-heat,
hold, and slow cooling, values entered for the last firing
will appear. To use these values again, press ENTER.
To fire without Delay or Alarm: Follow steps 1
through 7 below. Then from IdLE press START. To
use Delay or Alarm, see also page 6.
1 Apply power to the kiln. 8888 then IdLE
will appear. (Press ENTER if IdLE does not
appear.)
2 Press 1. CONE will appear. Enter cone num-
ber. (If the 1 key does not respond, your con-
troller uses Ramp-Hold only.)
3 Press ENTER. SPd will appear. Enter speed:
FAST (1), MEDIUM (2), SLOW (3). (Me-
dium speed will display as Std .)
4 Press ENTER. PRHT will appear. To use
Pre-Heat, enter time. Otherwise enter 0.
5 Press ENTER. HOLd will appear. To soak the
ware at the end of firing, enter a hold time.
Otherwise enter 0.
6 Press ENTER. COOL will appear. To use
Slow Cooling, enter cooling rate as degrees
per hour. (180°F/82°C is maximum rate.
Press 0 to turn Slow Cooling off.)
7 Press ENTER. IdLE will appear.
8 TosetAlarm: Press 7. ALAR will appear. En-
ter alarm temperature. (Press 0to turn alarm
off.) Then press ENTER.
9 To set Delay:Press 3. dELA will appear. En-
ter delay time. Press ENTER. (Delay zeroes
out after each firing.)
10 To start program, press ENTER once.
STRT will appear, then temperature. If
Delay was programmed, DELA will appear,
then time remaining until start. To stop the
program during firing, press STOP.
When program fires to completion, CPLT will ap-
pear. Press ENTER. IdLE will appear. To shut off the
alarm when it sounds during a firing, press ENTER.
Vent the kiln until moisture no lon-
ger fogs a mirror.