Heat oven using a waste oil burner???

[cdaeme]

I am just getting started in Powder Coating. I have been reading the forums over the past couple months looking for the oven design I would like to build. My shop is currently equipped with a household oven. The current choice would be a 6' x 6' x 8'. The real dilemma is deciding how to heat the oven. I like choices and backup options, so I would like to build my oven to run off electric with the option for backup heat. With all that said here is my idea.

I have been reading lately about waste oil burners on this website http://journeytoforever.org/biofuel_...earth/me4.html
I realize this is a little off the wall but I would like to get some input from anyone currently using the propane torpedo type heaters and professional natural gas burner boxes. What is the system / method used to contain the flame and keep it separate from the oven? The articles say it is possible to generate 1100 F with these heaters (not that I would attempt that) but this would be a very economical way to fuel an oven.

Thanks for any input and listening to me think out loud.
Jason