Butane amounts expected for Newbie

Thankful to have read a lot of information here and have decided to try making some bho.
Iv come to the realization that I will be making anything from shatter to goo with some butane left.
My question for you all is (and this is kinda a hard question) how much butane will be left and will that be an acceptable amount. I plan to take temp to 90 deg and slowly raise till it fogs, then overnight vacced.
Not dewaxing this is a simple attatable plan I hope to achieve. Any input appreciated.

Butane is considered GRAS by the FDA, with a standard for residual Butane of 5000 ppm.

What does the vacuum gauge read when it fogs?

It will purge faster at its melt point, so that the bubbles can readily escape. Melt point varies by composition.

At WolfWurx we picked the temperature by eyeball, which is the exact melt point by visual observation, on average around around 110F. Raise the material to 100F and then raise the temperature in increments until it melts.

WolfWurx purged cotton candy at around 110F and 10,000 microns/-29.5 Hg, and were around 375 ppm in four hours. At that temperature for that period time, decarboxylation in minimal, and the brief process time helps maintain monoterpene levels.

Thanks for the reply, this will be my first run, still have a lot of reading to do. -29.2 Hg was what I was thinking of using to take it up to 100-110 deg and ready to open valve 4 or more times to evacuate.

At 110F and -29.5 Hg after four hours you have 375 ppm, am I to assume this is an acceptable level? Or is there a final 24 hour purge your doing? What temp and Hg is that at?

To me 375 ppm seems acceptable. Im a novice and can only expect so much.

It is below 10% (500 ppm) of FDA maximums, which is the local dispensary standard.

I don't do a 24 hour purge because of monoterpene loss, but you can always run a sample and see how you like it.

Great thanks. My main concern was losing terps for the long purge. So maybe I try 110 f for 4 hours at full vac. The temps low which is good. I think those are very low number, less then breathing lighter fumes. Its weird its not in solution just trapped and still so hard to get out.
Not dewaxing will affect flavor and purity, later on I can do that. I just want to get a "good" product that is fun to smoke.
My extraction tube is for 1/2 oz so I plan on making a lot of little batches to get the hang of it. Thanks.

If butane is a concern you can take the final oil and dissolve in 1-2 ml of ethanol (95%) per 5g of product. Then remove the ethanol under vacuum. The worst you will end up with is trace amounts of ethanol. Because ethanol is higher boiling than butane it will be removed first.

The lipids with butane get washed out with ethanol? Hum I dont want to take it up to 170 deg f however.
That really is the good thing about ethanol extraction, I just like the solubility of butane and low boiling point.

outerstar said:

The lipids with butane get washed out with ethanol? Hum I dont want to take it up to 170 deg f however.
That really is the good thing about ethanol extraction, I just like the solubility of butane and low boiling point.

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The method I proposed would not remove the lipds as they are not volatile. You are distilling the residual butane off. If you have a good vacuum pump and right container you can remove ethanol at 30C. I use round bottom flasks to store my oil in. This makes it easier to attach a vacuum to.

Sweet thanks how cool Ill do that. You are putting the ethanol into solution along with trace amounts of butane (although its not really in solution?) then it purges it. Just a few drops really. Kinda got my head around that. I was looking at distilling butane last night and wanted to do it thanks so much. I have lots of lab ware. How do you get the oil out of the flask, just poors? Then another in the vacuum chamber? Sounds very similar to ethanal extraction, was very tempted to try that but I found such a good semi non polar solvent.

outerstar said:

Sweet thanks how cool Ill do that. You are putting the ethanol into solution along with trace amounts of butane (although its not really in solution?) then it purges it. Just a few drops really. Kinda got my head around that. I was looking at distilling butane last night and wanted to do it thanks so much. I have lots of lab ware. How do you get the oil out of the flask, just poors? Then another in the vacuum chamber? Sounds very similar to ethanal extraction, was very tempted to try that but I found such a good semi non polar solvent.

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You only need to add enough ethanol to dissolve the oil. More than a few drops (1-2mL per 5g).

My setup is in the thread https://www.rollitup.org/t/bho-how-i-do-it.979106/

My end product is a relatively thick oi/l so does not pour.

I use a chemical spatula to scrape the oil I need if I need a few grams. If you tare the flask you can calculate how much oil you have left.
Once I get down to about 5g I convert the rest to ejuice by adding 10mL of wax liquidizer. I then use a pasteur pipette to get out every last drop.

budchemist said:

If butane is a concern you can take the final oil and dissolve in 1-2 ml of ethanol (95%) per 5g of product. Then remove the ethanol under vacuum. The worst you will end up with is trace amounts of ethanol. Because ethanol is higher boiling than butane it will be removed first.

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If I did this with a dry ice bath underneath (-30 or so) would that separate out water into the ethanol and thus lipids?

Read your meathode, looks great. Maybe next time now as I want to keep things simple.

Going for the final 4 hour purge as not to boil off terps. Im then going send some off to see how much butane is remaining. If its acceptable amounts then Ill stick to this method and dewax this way in the future, thanks folks.

outerstar said:

If I did this with a dry ice bath underneath (-30 or so) would that separate out water into the ethanol and thus lipids?

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I doubt it. The lipids tend to form an emulsion in ethanol and do not separate out like they do with oil and water.