Groundhog Kiln
(as it relates to the pottery traditions of North Carolina).
The traditional Groundhog kiln is a distictive kiln type particular to the American South. A member of the cross-draft family, its characteristic form is a long, low rectangle, with a deep firebox spanning one end and a wide chimney at the other. It is often built buried up against a hillside or in the ground, hence the source of the name groundhog. The exact origins of the southern groundhog kiln is undetermined, but it has developed into two distinct regional sub-types within North Carolina. These two areas are the eastern Piedmont region, comprising of Moore, Randolph, and Chatham counties, and the Catawba Valley region of Lincoln and Catawba counties.
The eastern Piedmont became a center for saltglazed stoneware, while the Catawba Valley potters coated their stoneware pottery with an alkaline glaze consisting of crushed glass or iron cinders, clay, and wood ash. To the casual observer these two regional kiln types may appear the same. However, there are distinct features that have set them apart due to the traditions and practices of their particular locale. In the salt-glaze groundhog the loading and unloading is done through the firebox of a kiln that is typically of lesser volume than those in the Catawba Valley, yet with a taller chimney. The wall between the ware chamber and chimney is constricted in order to have a choking effect on exiting gasses. Wares are set on crushed flint rock to enable the salt vapors to pass underneath the pots, and fired for a longer time using hard woods for the initial burn, then with pine for the final blast. Stoked from a pit, the kiln is fed on level with the firebox, it being a large single hole with two draft holes near the base. The kiln's arch is of a smaller rise that those in the Catawba Valley, and has salt ports running along its length. After the kiln has been set, a bagwall is usually constructed at the front end of the ware floor.
The Catawba Valley potters load and unload their kilns through the chimney, which is lower and wider than the eastern Piedmont groundhog chimneys, and open into the ware chamber. Having unglazed bottoms, pots are set on a bed of sand within a kiln that is usually somewhat larger and more open than the saltglaze kilns, the arch sloping down to the floor. Generally, a bag wall is not constructed due to the height of the setting floor above the fire box. If one is built, it is very low in height. The firing utilizes pine from start to finish, and is stoked from a level that is even with the ware chamber floor and approximately three feet above the firebox floor. Wood is dropped into the firebox through, typically, three fireholes.
To read a very thorough and texbook study of North Carolina's folk pottery heritage, please consult Terry Zug's (Charles G. Zug III) Turners and Burners: The Folk Potters of North Carolina, published by The University of North Carolina Press, 1986.
