rocket mass heater, using old oil

so i want to make a rocket mass heater, for the shed in winter and also for a couple of other little things

does anyone have any comments about the following ideas/uses
-i want to use old engine oil to run it, i have a lot of oil and can get it free (if it is provided with enough oxygen and heat there are very little pollutants that can leave the exhaust)
-i want to be able to use it for *cooking* (im hoping to use the heat to produce charcoal and to act as a foundary to melt metals

has anyone heard of somthing like this?

if you can figure a burner in the burn tunnel, it should work. However, after reading this:
http://www.journeytoforever.org/biofuel_library/ethanol_motherearth/me4.html

My main concern would be keeping that burner clean. It needs to be easy to disassemble. It would seem easier to soak your wood in the oil and burn that. That way your burner is being continually replaced.

There seems to be some disagreement on the safety of burning used engine oil no matter the temp.

I am not sure if you meant to make charcoal with the RMH to use for melting metal or if you figured on melting metal directly on the RMH. In would suggest that the RMH will not have much in the way of parts that get hot enough to melt anything beyond solder or printers metal (not even sure about those). The iron parts of the RMH last over 20 years.

I would try a drip feed onto a fiberglass mat for this purpose

very low tech and easy to monitor

Brice Moss wrote:
I would try a drip feed onto a fiberglass mat for this purpose

very low tech and easy to monitor

I believe that you can burn oil and water together, producing a very hot flame. Drip 1 drop of water to 1 drop of Oil if I remember correctly