Fired Arts & Crafts
Basic Kiln Operation
Friday, 22 October 2010 12:54

The general operation of a kiln is quite simple. Don't be overwhelmed by terms that may appear intimidating. If words like cones, thermocouples, kiln sitter, stilts, kiln wash, ramping and others appear to be a foreign language, don't fear; they will quickly make sense.

The components of a kiln are not that complex. Every electric kiln has the same basic makeup. You have a firing chamber where you place items to be fired, some form of heating elements in the walls and possibly the lid of the kiln, and controls for turning the kiln on and off. Much like baking a cake, you need to place the item(s) inside, turn it on and set the time for it to stop. On an oven, you would set a timer to check if the item(s) are done, whereas most kilns will shut off when the firing is completed.

Two basic kinds of kilns are available, manual and automatic. Manual kilns have switches that are turned on and may require you to change them from low to medium and finally high in the beginning of the firing process. Some manual kilns have switches that adjust the temperature automatically, so you don't have to do anything after you turn them on.

Most manual kilns come equipped with a feature called a kiln sitter. This remarkable invention is what turns the kiln off when it is done. When you load your items in the kiln, you place a small piece of special clay, called a cone, in the kiln sitter.(There are different cones for each kind of firing you do, such as greenware, glaze, decal, etc.) When the kiln reaches temperature, the clay bends, triggering a switch that stops the kiln.

Automatic kilns usually have a controller that you set or program to go to a certain cone number or temperature. When the kiln reaches the desired temperature or cone number, a probe on the inside of the kiln, called a thermocouple, alerts the controller on the kiln to shut off. Each kiln manufacturer may have a variation of this kind of control. Electronic controllers on kilns manufactured today have really been simplified for the user. Many also offer a variety of options for more precise programming and versatility.