Skutt Firebox 8 - Manual (Page 6)

6
6
K
iln
o
peraTion
Infinite Switch Control
d
eScriptiOn
The Infinite Switch is the main temperature control device for your kiln. The switch, located on the front of the control
box, is called an “infinite “ switch because it has an infinite number of settings between Low and High. As the switch is
turned up the kiln heats at a faster rate and will achieve a higher temperature. The markings on the switch are meant to be
used as reference points not as specific settings. Therefore it is ok to position the switch anywhere in between these mark-
ings. Factors such as the mass of the load, the age of the kiln and fluctuations in voltage will affect the rate at which the kiln
fires.
O
peratiOn
When using your kiln you will want to control the heating/cooling rate and hold at specific temperatures. As mentioned
earlier the performance of your kiln will be affected by several factors the main one being the mass of the load in the kiln.
Over time you will get a feel for how your kiln performs in different situations. Here are some tips to give you a head start.
The Heating/Cooling Rate
For many smaller items the heating rate is often not important however for certain materials such as larger glass proj-
ects, ceramics, and molds, a slower heating rate may be necessary to avoid thermal shocking the ware. When in doubt bring
your kiln up to temperature slowly.
The slowest setting on the FireBox 8 is LOW. At a low setting with the kiln empty the kiln will average about 300 ºF/
hr. (167 ºC/hr.). To calculate the heating rate as it is firing simply measure the temperature rise over a one minute period and
multiply that number by 60. This should be done every 10 or 15 minutes since the rate will begin to slow as the kiln reaches
it’s peak temperature for that setting.
To increase the rate turn the switch up and to decrease the rate turn the switch down. To achieve a slower rate than 300
ºF/hr. (167 ºC/hr.) you will want to either prop the lid or turn the switch alternately from OFF to LOW. Every time you turn
the switch you should recalculate your heating rate to see if further adjustment is needed.
For many smaller projects simply turning the switch to OFF and letting the kiln cool naturally is fine. For other items
that require a slow cool or annealing you will want to lower the switch setting and measure your rates just as you did with
heating the kiln. If you want to cool faster than the kiln is allowing you can crack the lid to allow heat to escape.
Holding At Temperature
In order to set the kiln at a particular temperature it will be necessary to make adjustments to the settings until it stabi-
lizes. As you work more with your kiln you will get a feel for what settings will achieve particular temperatures. Keeping
notes will help you achieve a stabilized temperature with fewer adjustments. The faster the heating or cooling rate the more
likely you are to overshoot your holding temperature. If your kiln is set to a fast rate, turn down the switch setting before you
reach your temperature. Consult your notes to find the settings that hold at certain temperatures. It may be necessary to turn
the switch up and down a few times before finding a setting that holds it at your desired temperature.
t
hiS kiln waS deSigned tO Fire Very FaSt thereFOre it haS a lOt OF pOwer FOr itS Size
. n
eVer
leaVe yOur kiln unattended
. a
t SettingS aBOVe
4
the kiln teMperature can cOntinue tO cliMB
and cOuld perManently daMage the Brick and the eleMentS
. n
eVer allOw the kiln tO Fire OVer
the rated teMperature
.
Using the Pyrometer
The digital pyrometer provided with your kiln is very simple to use and understand. Once you have it set up (see in-
structions under “Kiln Set-Up”), all you need to do is use the switch located on the front to turn it on and off. The pyrometer
reads temperature in Degrees Fahrenheit. If you need a Celsius pyrometer one can be special ordered.
The meter will read temperatures up to 1999 ºF (1093 ºC). The kiln is capable of achieving temperatures beyond this
rating. If the temperature exceeds 1999 ºF (1093 ºC), the pyrometer will read “1”. If you see the pyrometer with this display
turn the kiln (not the pyrometer) off immediately. Once the temperature drops below 1999 ºF (1093 ºC) the pyrometer will
read the correct temperature and you can turn the kiln back on. When the battery is low the pyrometer will display “LO
BAT” in the top left corner.