How to Use a Fireplace as a Kiln

Place a few large stones or a cast-iron rack in the center of the fireplace. If you are using rocks, make sure that they do not contain porous holes that can trap moisture and cause the rock to crack when heated.

Place some crumpled-up newsprint in the bottom of the fireplace and cover it with kindling piled 4 inches high. The kindling and newspaper should surround the rocks or cast-iron stand. Light the newspaper with a match or lighter and let the kindling become inflamed.

Place the clay items in front of the fireplace while the kindling fire burns. This helps the clay to complete the drying process.

Allow the fire to burn down until only a bed of coals remains.

Place the clay items on the rocks or rack, which should now be thoroughly heated.

Place additional kindling on top of the bed of coals. Pile it approximately 3 inches high. Do not place any kindling on top of the clay items.

Place additional kindling over the top of the rack or rocks and the clay items, in a tepee tent shape. The kindling should not touch the rack or rocks -- or the clay -- but should enclose the clay entirely so that it cannot be seen. The tepee of kindling effectively creates an oven by trapping in the warm air around the clay.

Monitor the fire for three hours, adding kindling to the tepee as it burns down. Do not allow the clay to become exposed to the outside air.

Allow the fire to burn out until only white ash and red embers remain.

Soak the leaves or hay in water and place it on top of the ash. This causes the fire to smolder out and die.

Let the fire cool down until it is cool to the touch, which takes several hours. Remove your clay items from the fire and wipe them down with a damp cloth.