Important Guidelines
The Embedded Heating Element
The heating elements of your kiln are embedded into the ceramic fiber firing chamber. The firing chamber surface is hardened to a depth of ¼”. This makes the fiber more dura- ble. It is important that you do not touch the firing chamber with sharp objects. These can penetrate the fiber surface and contact the heating element, which is a shock hazard.
Note: The heating element under power is danger- ous. Do not touch the element with anything! Turn the kiln switch off before inserting an enameling fork into the firing chamber to remove a shelf.
The Clicking Noise
Do not be concerned if your kiln makes a clicking sound during firing. Your kiln contains a relay, which sends power to the element. The relay clicks as it cycles on and off to maintain the correct temperature.
Check Thermocouple
You will find a small rod, called the thermocouple, ex- tending into the firing chamber. The digital controller senses temperature by reading a voltage from the thermo- couple. If this rod is pushed out of the firing chamber, the kiln will assume that the firing chamber is cold. This will re- sult in an
Vacuum the Kiln
Clean the kiln before firing glass, enameling, or ceramic glaze. (Cleaning is not necessary when firing silver or gold clay). Use a soft brush nozzle on a vacuum cleaner to remove dust from inside the kiln.
Removing Hot Ware
To remove hot ware from the kiln, turn off the kiln. Carefully slide an enameling fork un- der the shelf. Place the hot shelf on a large ce- ramic kiln shelf in front of the kiln. Wear thick work gloves.
Firing Log Book
Record the following information in a firing log book:
■Date
■Firing temperature, speed and hold; or Ramp/Hold pro- gram
■Starting time
■Total firing time
■Type of pieces
■Firing results
As you gain experience, you will find a wealth of informa- tion in your firing logs.
Low Temperature Holds
A low temperature hold (i.e. 200° - 300°F) is more diffi- cult to maintain than higher temperature holds (1400° - 1700°F). At low temperatures, turning on the heating ele- ment affects firing temperature to a larger degree than at high temperatures.
When holding at a low temperature, heat the kiln slowly. Otherwise the temperature may overshoot the hold temper- ature before the element turns off.
Avoid Contaminating the Heating Element
Contact with silica or silica bearing com- pounds, such as kiln wash, glass separator, alumina hydrate, glass, enameling powder, and ceramic glaze, will ruin the heating element. Never fire glazed ceramic ware, glass, or enameling
directly on the firing chamber bottom. Use a ceramic shelf on short posts to protect the bottom from glaze drips, glass and enameling powder.
Caution: Some kilns contain a heating element embedded in the bottom of the firing chamber. Ma- terials such as glass and glaze, if absorbed into the fiber firing chamber, can ruin the element. This type of damage is not covered by warranty. Prevent glass separator, kiln wash, and alumina hydrate from falling from a shelf onto the firing chamber. These materials can destroy the element.
Note: If a contami- nant such as dripping glass or glaze embeds into the firing cham- ber, unplug the kiln. Gently scrape off the contaminant with a knife, being careful not to damage the heating element. Vac- uum the kiln.
The Effect of Silver Residue on Glass
Firing silver clay leaves traces of silver in the pores of the firing chamber. Sometimes there is enough silver residue in the kiln to affect colors of glass. For instance, green might turn yellow.
Note: Before firing an important glass piece in a kiln used for silver clay, perform color tests. Fire small samples of each glass color on a base sheet of clear glass. Place the glass on a fireclay shelf (not the soft fiber shelf).
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