On top, I have cut windows into the tube. These extend from outside the vial to slightly below the constriction. The outside part of the windows allow for the Venturi effect; the inside part equalizes the pressure between the two compartments, again helping fuel flow between them. The so-called airflow control basically adjusts the size of the outside-windows; it did not work so well for me.

If your vial doesnt have a constricted mouth, I reckon it’d still work — the metal would just press right against the glass. The glass would absorb quite a bit of heat from the insert, so I’d recommend using Pyrex/borosilicate glass; it may also take longer to heat the fuel. Alternatively, you might be able to use a freestanding tube that is narrower than the vial.

To light the burner, fill it almost to the brim with fuel and ignite it using a lighter through a window. It’d burn slowly for a few seconds, and come to life when the fuel is warm enough. Be careful.

Oh yeah… don’t use Rockstar cans; they’re coated with this layer of plastic that really starts smoking/stinking following ignition. I hope this helps.

Also, I am not exactly sure about the bottom panels of the picture. I believe this is the airflow control mechanism? Are the corners you cut (bottom left panel) just supports that go in the airflow holes?

Does burning 100% ethanol still produce much heat?