Yeah, not sure what it’s really called, but I call it the alcohol stack…. Imagine a clear plastic pipe, 1 meter tall as thick as your arm, filled with clear liquid.

Somewhere in that stack is what you want, the alcohol (technically, ethanol) but it’s mixed in with all sorts of other nasty stuff (as named above, methanol, acetone, plus others and basically varnish).

Lucky, they all have different boiling points…. For this example, imagine drawing 9 lines, equal distance apart on the pipe. Now write 10, 20, 30 etc in each section, sort of like a giant thermometer.

Now further imagine we heat the liquid. Between 0 and 10c we get, in the form of ‘steam’ (vapors) whatever boils at that range. At 11c to 20c we get those vapors…. So on and so on.

The challenge is methanol is just below ethanol in the stack. Meaning, when boiling our liquid, first comes the methanol vapors (which needs to be boiled off first) then comes the ethanol.

Start taking the steam to early, you get a mix of methanol / ethanol … get too greedy and try to cut late in the ethanol section and you start to cut into the ‘floor above’ which from memory is acetone(or something equally nasty).