IST'S JOULE THIEF HEATER UNITS

[guruji]

The 1/8" has to be (exactly) 1/8"
Oil (not water) has to be between the pan walls,
but not filling up inner pan.  My sources swear it works.
Both pans should be of the same metal I think.

In the link that you've showed before it's water that they are boiling. Impressive.
Today I opened it again but it's not 1/8" that I have it's a bit wider maybe that's why it did'nt work.
Hope to find the right size container that fits exactly. I will try it again. The info that I have the inner should be aluminium outer not important.
I did oil but any liquid should work.

[Foggy-Notion]

That's another thing, you can't find any pans that will fit into one another with that exact gap, not even from different manufacturers.  It's as if they all cooperated with some hidious horned head hancho in hell.