Woodfiring is an ancient method of pottery finishing. The techniques and process we use today are still very similar to the old traditions. When compared to common modern electric or gas firings the woodfire process is extremely labor and time intensive, but yields completely unique results.
The work begins months before each woodfiring takes place. Prior to each firing the kilns must be cleaned and any wear-and-tear damage repaired. Wood must be gathered and cut to length with chainsaws then stacked prior to firing. At the beginning of each kiln firing thousands of pieces must be wadded with small balls of clay that will prevent them from fusing to other pots or kiln shelves during the firing. Each piece must then be carefully loaded into the kiln by the artist mindful of the location and orientation that will best encourage the colors, flashing, and ash accumulation they desire for the piece.
The firing itself begins when a small fire is lit outside of the kiln to slowly heat the work inside. After several hours coals are moved into the kiln’s firebox and wood is added to slowly build temperature inside; from that point forward wood is stoked around-the-clock for the duration of the firing. The kiln must be constantly monitored and stoking patterns adjusted to gain temperature and achieve desired atmosphere and temperature for the firing.
For the duration of a firing the ash from the burning wood is being deposited on all the pots, accumulating like snow. When the kiln is hot enough, about 2300 degrees Fahrenheit, the ash will melt and fuse with the pottery forming a natural wood-ash glaze. The colors of this ash glaze are mostly dependent on the sort of wood used during the firing but are generally yellow, green, or blue. In addition to ash accumulation, flame is moving like a river past all the pots marking them with subtle reds and oranges in an effect called flashing. These natural markings and ash accumulation are what make each woodfired piece completely unpredictable and unique.
Every kiln is different and the experience of past firings slowly forms an understanding of expected results. However, artists must be willing to relinquish some control when firing their work this way; in return the unexpected results can be amazing.