Dear Sir,
Some folks have bees in their bonnet, but I appear to have PTFE tape in mine.
In 2018 I wrote an article in Common Stock about the evils of using PTFE tape on the hemp bindings of chanters and drones. I firmly believed that I had been clear and lucid, and thus had hoped that this would have cured the Piping World of this wretched practice. However, it has come to my notice that there are still pipers who are persisting with this hazardous practice. Traditionally the hemp bindings on the tenons take advantage of the fact that the rough nature of hemp will cause a tight friction-fit in the stock.
PTFE, or plumbers tape, however is made of Teflon; a man-made material specifically designed to reduce friction to the minimum. So, by applying it, the Misguided Piper increases the possibility of a tenon slipping out of the stock with the possibility of ruining the reed. If you need to tighten these tenons you should add hemp or possibly sewing thread.
It is perfectly acceptable to use PTFE on drone slides where you take advantage of the reduced friction afforded by the tape when tuning the drones.
So, you have all been warned! And I vow that I will not issue another statement about this until 2022 at the earliest.
Yours aye,

Julian Goodacre Bagpipe Maker
(disgusted of Peebles)