I get that when I put too much oil on my dabber for it to evaporate in one go (I smoke a lot of oil)
I just retorch my nail and burn all that shit off... sometimes you can smell the oil fill the air as the nail heats up under it.... thats probably good oil, but I do wayyyy to many dabs to think about scraping my nail like that
If your torching your nail then dabbing your oil, then nothing is burning, nothing is converting into other chemicals... just liquefied cannabinoids going from liquid to a gaseous vapor.. and then re-solidifying into a liquid again.
your probably better off keeping a piece for ONLY oil and keeping it really clean except for the oil...
then do a QWISO hash extraction from it... again I've never had to, i always have too much fresh oil - but some people do.