I have a heat box I built about 18 years ago, It has a limit switch with 180 degree capability. It runs 4- 200 watt incandescent bulbs. If I am using epoxy, it usually takes a bout 4 to 6 hours to cook... I am a engineer for a hotel, we use ballast curly tail bulbs. Don't kid yourself you can burn your fingers on them too. However . there still is Heat lamp bulbs 125 watts and up, one could use. A simple stove pipe, with a heat gun does the job too. It would need to be open at both ends, or the heat gun probably would shut down. That is if it is of good quality. I wouldn't walk away too long with out some type of limit switch. I like the Idea of a small quartz heater, they usaully have a built in limit. Anyway , What is your reason for the box anyway. Unless you are going to glue up fiberglass, You wouldn't need anything that drastic, I wouldn't think? I use space heaters , heat guns and Water pot steam boiling for the tough ones.Good luck hope this helped. Denny