From time to time, I have seen requests for information on thermostats for use in hot boxes. I just thought I would pass along one option that people might use. I purchased a single element hot water heater thermostat from Home Depot for around $8.00. It will control from 100 degrees to 150 degrees so the range is about right for most hot box applications. The thermostat is sold as a replacement for one used on an electric hot water heater. It has about a 10 degree range after it shuts off until it comes back on again.
I just thought I would pass this on so others that may be looking for a thermostat can use this reasonably priced unit that is readily available. Hope it helps. - jwingman