This is an "old" refrigerator that I use as a kiln. After removing all the "inners", I drilled a series of holes in the top and bottom. After placing a 15 watt bulb inside, this allowed warm air to flow in the bottom and out the top.
A bowl that is "rough turned" to about 3/4 inch thick will be dry in about thirty days. Then it can be reshaped, sanded and finished with oil, varnish, shellac, etc.
Some of the bowls now drying are Chinese elm and ash. The temperature stays about 80 degrees F.