An artist might choose to use an ordinary microwave oven to fire his small pottery pieces. The microwave kiln is a small container created by placing a hood over a base. A white fibrous substance insulates the inside of the container and a black compound inside the container absorbs the radiation emitted during the microwaving process. This little kiln can heat up to 1650 degrees Fahrenheit, hot enough to successfully fire small sculptures, beads or other small objects.
The backyard barbecue grill provides another off-the-beaten-path method for firing small clay objects such as pinch pots. According to the Ceramic Arts Daily, this alternative kiln works best for firing objects made from micaceous (mica-containing) clay or raku clay. Coals normally heat up to around 1100 degrees Fahrenheit, a temperature that will work for very small items. An artist may raise the temperature inside the grill to accommodate larger pieces by surrounding the coals with wood scraps.
Artist Careen Stoll of Portland, Oregon, created a large kiln that uses wood embers and waste vegetable oil. Stoll's inspiration for inventing her kiln was her success in fueling her diesel truck with vegetable oil that would otherwise have been discarded. With 45 cubic feet of stacking space, Stoll's kiln will accommodate large pieces or multiple smaller pieces. Stoll built the kiln, which she named "The Tin Man," in her backyard over the course of a year. Once she had completed the kiln, Stoll spent an additional year of experimentation to find the best method to use for firing her pieces.
The July/August 1981 issue of Mother Earth News provides detailed instructions for a primitive method of firing pottery that is appropriate for backyard use, particularly in rural settings. An artist can place this kiln in a shallow hole in a cleared outdoor area, and can construct the kiln using only dry twigs, shards of broken pottery, scrap metal and dried cow or horse manure. Although most pieces fired in this type of kiln retain their original color, an artist may achieve special effects by using more manure to create more smoke, or by carving into a partially-baked piece or rubbing the piece with a spoon or smooth stone.