This stuff laughs at molten solder and spirit burners. Heat stripping is
no good because flame temperatures high enough to decompose the enamel
will also oxidize the copper underneath. As far as I know, the only ways
to remove it are by scraping, sandpapering or filing... all of which are
difficult to do without nicking the copper wire.

So how do the professional winding shops do it?

--
73 from Ian GM3SEK

GM Ian, guess you're getting used to the Highlands by now. Had a great trip
to Scotland for 3 weeks in June, Blair Athol to Glencoe. Not long enough
though. Yes, Polythermaleze and heavy polythermaleze and Formvar are the
chrome vanadium steel of insulations. If you want to wind wire tightly
around a faceted diamond without damaging the insulation, those are what you
use. Basically, One divided by Bicelflux.

Professional winding shops invest in a machine that looks and operates
somewhat like an electric pencil sharpener. It abrades the insulation and is
automatically set for each different wire size. Needless to say, they come a
bit dear. (Not as dear as diesel fuel in Pitlochry, but dear!)

Regards
W4ZCB