Peacock VaseTroubleshooting Electric Kilns

By Alice Lane | Submitted On May 31, 2010

The first principle of troubleshooting electric kilns is avoiding trouble in the first place. Keeping a kiln clean is extremely important since dirt, dust, glaze drips, and moisture can all contribute to the decline of a kiln's efficient operation. Regular inspection and thorough cleaning of a kiln should be part of every potter's regular schedule. The interior of the kiln as well as its upper perimeter should be vacuumed. The interior of the kiln and especially its coils should be examined minutely for drips of glaze which should be chipped off as soon as they appear; otherwise successive firings drive the glaze more deeply into the brick or coils. Drips can be removed from the coils by heating the coils until the drips soften, then loosening and gently breaking them off with a needle-nose pliers. Always be sure to turn the current off before working on the coils. If any coils pop out of their grooves, reheat the coils until soft and compress them carefully back into place.

Problems in kilns are often caused by loose electrical connections. After every dozen firings the current should be turned off and the electrical box should be inspected for loose connections, corroded parts, and frayed wires. Electrical current causes vibrations which can cause the connections between the terminal and element to loosen. These bad spots can rapidly decay. Be sure that no wires touch the element tails which come through the kiln wall and that the element tails are not in contact with the outside jacket of the kiln. Be sure to vacuum these places thoroughly to remove dust from kiln silver clay when you are cleaning the kiln. The jacket should have a porcelain insulator to protect it from electrical connections. If the kiln is multi-sectioned, then there will be outlets, plugs, and electrical cord connecting the sections to one another. These components can wear out, and should be examined periodically. Any misshapen or darkened plugs and their corresponding receptacles should be replaced. Examine the plug, receptacle, and cord which connect the kiln to the electrical service as well. If the kiln lid is hinged, examine the hinge mechanism for security, corrosion, and alignment. Moisture is a common cause of deterioration in kilns. The kiln should be ventilated properly with a commercial ventilation system, or by locating it in a well ventilated area. This also protects the operator from toxic fumes.

Problems in both a ceramic and glass kiln can manifest themselves in different ways. One of the most common is when suddenly the kiln fails to reach temperature. The fault could be a bad coil, switch, interbox outlets or plugs, the power cord or fuse box, or any of the connecting wiring. To determine the cause of the problem it is best to work back from the symptom. If the kiln won't reach temperature, turn it on high and see whether or not all of its coils are glowing with color. If one or more coils do not, then you have found a symptom. However, even if a coil doesn't become red it may still be working, so it can be tested by taking a piece of paper and touching it to the coil. If the paper burns, then the coil is working; if not, the coil is broken or else something is keeping the coil from getting power. Take a voltmeter and touch its probes to each of the coil's ends to see if electricity is flowing through the coil. If so, then for some reason the coil is receiving power but still not heating up (i.e. it is broken and should be replaced). If there is no power, then you must work back towards the fuse box to find where the failure is occurring. Since live current and exposed connections can cause severe shocks, be extremely careful when touching the meter's probes to connections. Frequently the problem is not in faulty coils but in broken switches or loose electrical connections.

Troubleshooting problems in both a glass kiln and in electric kilns is simply a matter of using step-by-step logic. Many problems can be avoided by simply cleaning and vacuuming the kiln regularly to remove glaze drips and kiln silver clay dust.

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