I'll have to try a longer soak next time I make some BHO. I kept everything including the cans of butane in the freezer and basically did it like QWISO.
I swirled it for just a minute on the clock then added some fresh butane and did the same for a wash. I never really kept track of the yields but was quite happy with the results.
I'm curious why you wouldn't have everything kept below freezing then the butane in the thermos would have stayed liquid much longer as it's boiling point is only -0.5C.
When I did mine I used dried and cured bud but have lots of fresh frozen bud in the freezer to work with and was going to use naphtha for that but I have a bunch of cans of 9x filtered butane sitting around.
When I did my last batch I used 2 1L flat-bottom boiling balls. One outside the freezer with the filtered butane/oil mix connected to the 2nd in the bottom of the freezer by a 20' coil of 3/16" copper tubing. The butane in #1 boiled fine with no added heat and the room temp at 12C in my mudroom where the freezer is. I had a few boiling chips in there to help things along.
I could just use the captured butane right away to do more pot and got way more mileage out of a couple cans than letting it evaporate. Had half a thermos full of the recycled butane and just left it in the freezer but when I checked it a couple weeks later it was empty. Good thing I wasn't smoking when I went into the freezer for stuff when it might have been full of fumes.
I have an idea to use a propane cylinder to save that butane in for later use. As long as it's kept cold it works like any other liquid but liquids like that have too high a vapour coefficient and unless under containment to build pressure will get out of almost anything.
Still looks greenish at the start. Camp stove butane back then.
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Looks better now.
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Rinsed the ball out with room temp ISO then evapped that off over a pot of simmering water with lots of stirring. I never decarbed it as it was meant for smoking.
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