Build A Waste Oil Furnace
This video shows the build of a gravity fed drip waste oil burner this is the one of the simplest design for maximum heat and flexibility the concept behind this burner is that oil does not burn but the fumes it gives off when the oil is boiling the deeper the pan the harder is it to maintain an efficient boil a cast iron pan maintains the higher temperature the best and does not threaten.
Build a waste oil furnace.
Source : pinterest.com