I'm not heating super hot. I'm just putting a jar into hot water that's just slightly below simmering. But when i put it in the chamber, it starts boiling up hard. Done 3 purges so far.
I have done large runs that take 24-48 hours of constant attention and stirring toget a clean product, at 140* anyway. You cut time off of purging with every increase in temp, just as decarboxylization increases with the same heat.
So for hi THC, lo CBD...a long low temp purge is in order, unless you have some ungodly source of vac. I think mosy people work around 25 inches. Thats about the most a gettro setup will maintain.
So at 25" of vac at 140* ....on a larger run...I have sat there for 2 days and the hotplate never goes off. It requires constant stirring due to the constantly changing viscosity of the oil. The deeper the layer of oil...the more difficult to purge.
The pain in the ass is this....the tiny bubbles will fool you. They can SEEM to be gone, but after vigorous agitation....you will notice the champagne like lines still bubbling up. Thats what takes forever. Thats the diff in almost clean... and clean.
Strains also play a role in how quickly and effectively the purge goes. Terpene levels are different....it causes different viscosities in different 'strains' of oil. So one "recipie" for purging may not work on all strains. It will be a base, but you gotta watch that oil!!...See what its doing. Those bubbles have to get gone.