I forgot to say something that was used to do in the old times with
old pot stills by old distillers (everything is "old"):
to cover with a wet,rough piece of tissue (e,g, a piece of the cloth
of juta bags) the superior part of the still, the part made as a
dome, where the vapours climb before to go into the arm line (or
swan neck, as you like) and sometimes wetting that one with some
drops of fresh water.
Such in this way they were getting a rough separations of spirit
components (in italian language that operation is
Now, is better to have a column but, if you have a pot still like
what you have, should be interesting to act as I described.
Ciao a tutti