i am terrible at purging my bho, post your method to help me and others

So I have a 1.9cuft oven and a small CLS I have been playing with. I got the hang of running the the material but this purge thing has been giving me trouble. I have been losing clarity and getting buddery patties over night after i run. good and bad, old and fresh material. I am so confused on what im supposed to be doing here, i think i have been reading too much lol. Everyone seems to do something different too not helping.



my method:
i like to pour on to silicone mats after extracting, i have used parchment and would like to use ptfe but this is where i am at. i dont think that the mats are giving me trouble.

next i set the mats in pre heated vac oven. temps i have used range 85-110. lately been using 95-100 wherever the oil seems viscous enough for the bubbles to pop.

after about an hour of sitting in the oven i pull vac. by this time the oil has come up to temp and is done moving around. i pull a small vac about 10-15 and leave over night usually. next day i raise the vac and the temp a couple degrees. if its stable after 24hrs i will continue for longer.

what am i doing wrong?

questions for people who post responses:
1. do you pour or scrape?
2. do you pour on ptfe, parchment, or silicone mats?
3. starting temp?
4. starting vac psi?
5. how many days spent in oven?
6. how much do you purge at a time?
7. do you flip?

Hi MrKushPants.

I think your on the right track but just need a few pointers. I wouldn't pour onto the silicon mats for starters. Either pour into a pyrex dish, ptfe lined dish or into parchment when there's a small amount of liquid butane.

Next step I believe you do right. Let the oil preheat in the oven for 30 mins or until bubbles are roughly smaller than a quarter size.

HERE is where you change things up. Start by pulling a vacuum to -25 to -26.5 hg and seal off chamber. The oil will spread itself out into a muffin. Keep an eye on it and once any part of it collapses pull a full vacuum down to -29.5hg and seal off. Temps should be like you said high enough to allow bubbles to pop. I like to run the pump every so often to pull evaporated matter out of the chamber. Watch for bubble action to slow then release vac, flip and pull -29.5hg. Run the pump every so often until the reaction stops.

After talking with a few ppl in other threads it seems that the low and slow tech isn't actually ideal. For example I had been using temps like 90-100 and leaving my oil in the chamber for 3-4 days. After bringing my temps up to 105-110 i am able to finish what took 3-4 days in a single day. The terps seem to be the same with way less time. Wish I could test, but no harshness compared to my other oil.

Hope this helps you man. There is tons of info here if you do some digging. I know I just posted recently about it in another thread and we had a good conversation.

[FONT=Arial, Helvetica, sans-serif]questions for people who post responses:
1. do you pour or scrape?
2. do you pour on ptfe, parchment, or silicone mats?
3. starting temp?
4. starting vac psi?
5. how many days spent in oven?
6. how much do you purge at a time?
7. do you flip?

My answers sorry got caught up in the first post...

1. Pour
2. Pour onto parchment
3. 105ish
4. Initial vac gets pulled to 25 - 26.5hg till muffin collapses, then full vac. (Just so oil doesn't blow up to big and get messy)
5. 1-2 days now. Old tech was 3-4.
6. Running for personally but running very often. 7-10 grams of oil per run
7. I flip 2 times. Once bubble action stops I flip, preheat, vac. The one more flip and I call it done.
[/FONT]

If your stuff is too soft and sticky then excess water pickup might be whats causing it, in that case purging the butane completely won't fix the problem. Can't hurt though.

thanks so much [FONT=Arial, Helvetica, sans-serif]jmewsk[/FONT]. i am still digging here to see what i can find i saw some of your posts somewhere else on a thread

https://www.icmag.com/ic/showthread.php?t=334561

lots of good info there. i believe i have just been over purging my stuff. i was lead to believe that i needed to purge for a long time. its all coming together and i have a bunch of practice material

jmewsk said:

Hi MrKushPants.

I think your on the right track but just need a few pointers. I wouldn't pour onto the silicon mats for starters. Either pour into a pyrex dish, ptfe lined dish or into parchment when there's a small amount of liquid butane. will try to use parchment until i get ptfe ordered here soon. why do you recommend not to use the mats? maybe less places for nucleation.

Next step I believe you do right. Let the oil preheat in the oven for 30 mins or until bubbles are roughly smaller than a quarter size.

HERE is where you change things up. Start by pulling a vacuum to -25 to -26.5 hg and seal off chamber. The oil will spread itself out into a muffin. Keep an eye on it and once any part of it collapses pull a full vacuum down to -29.5hg and seal off. Temps should be like you said high enough to allow bubbles to pop. I like to run the pump every so often to pull evaporated matter out of the chamber. Watch for bubble action to slow then release vac, flip and pull -29.5hg. Run the pump every so often until the reaction stops.
this makes sense after reading the other thread i posted at the beginning of the thread

After talking with a few ppl in other threads it seems that the low and slow tech isn't actually ideal. For example I had been using temps like 90-100 and leaving my oil in the chamber for 3-4 days. After bringing my temps up to 105-110 i am able to finish what took 3-4 days in a single day. The terps seem to be the same with way less time. Wish I could test, but no harshness compared to my other oil. i am not worried about terps as much as i worry about butane! but the high heat i believe is fine if you are purging shorter times.

Hope this helps you man. There is tons of info here if you do some digging. I know I just posted recently about it in another thread and we had a good conversation.

Click to expand...

^ "will try to use parchment until i get ptfe ordered here soon. why do you recommend not to use the mats? maybe less places for nucleation."

Nothing wrong with silicone mats for purging on. Just don't scrape them with a sharp tool, the same caution goes for silicone coated parchment paper.

Teflon/PTFE has no where near the magic non-stick power of silicone. That goes for sheets, and coated pans.

SkyHighLer said:

^ "will try to use parchment until i get ptfe ordered here soon. why do you recommend not to use the mats? maybe less places for nucleation."

Nothing wrong with silicone mats for purging on. Just don't scrape them with a sharp tool, the same caution goes for silicone coated parchment paper.

Teflon/PTFE has no where near the magic non-stick power of silicone. That goes for sheets, and coated pans.

Click to expand...

Never used anything but PTFE and thats what I recommend using. Its available and its not too expensive either. Why use silicone if you do not have to?

^ you don't know what you're missing...


I usually use my calibrated dial gauge to make sure I never go below -29.5" Hg, today I used the micron meter exclusively, and found it much easier to follow the pressure level.

$300/oz MMJ delivery nuggs, SCLab's found ~30% cannabinoids.

27.9g nuggs

9.90g product

35.5% return

~30/g for what I think is awesome oil, not too dark considering I ground the starting material, and soaked it four times in n-butane.


115F down to -29.5" Hg in a thin film, pulling several muffins, and when the bubbling slows way down it's done. Less than an hour in the vac chamber today. Stable shatter, it won't ever turn to wax.

Nice run brother Sky!

SkyHighLer said:

^ you don't know what you're missing...


I usually use my calibrated dial gauge to make sure I never go below -29.5" Hg, today I used the micron meter exclusively, and found it much easier to follow the pressure level.

Good point! There are 760,000 microns in at atmosphere, and only 29.92" Hg. One inch is 25,401 microns and 29.92" -29.5"=.42" Hg or 10,668 microns.

I rounded off at 29.5" to throw in some safety factor for gauge calibration and ability to actually read on most gauges, but -29.8", or +.12" Hg (3048 microns) is closer to the edge where we appear to lose our dance with the devil.

If we're not controlling vacuum by bleeding in N2, we may pull lower than 29.5" Hg, but I limit it to about 3050 microns.

$300/oz MMJ delivery nuggs, SCLab's found ~30% cannabinoids.

27.9g nuggs

9.90g product

35.5% return

Clearly a bragging rights return. Judging from the cloudiness, some of that weight may be plant wax.

What temperature did you do the extractions at?

~30/g for what I think is awesome oil, not too dark considering I ground the starting material, and soaked it four times in n-butane.

Nice color! What strain and what color trichomes?? Looks young "Sativa'ish", with minimal C-30 cyanins.

115F down to -29.5" Hg in a thin film, pulling several muffins, and when the bubbling slows way down it's done. Less than an hour in the vac chamber today. Stable shatter, it won't ever turn to wax.

Click to expand...

Aroma, flavor, effect? Objective, but still the test of the pudding....

Gray Wolf said:

I rounded off at 29.5" to throw in some safety factor for gauge calibration and ability to actually read on most gauges, but -29.8", or +.12" Hg (3048 microns) is closer to the edge where we appear to lose our dance with the devil.

If we're not controlling vacuum by bleeding in N2, we may pull lower than 29.5" Hg, but I limit it to about 3050 microns.

Click to expand...

Nice! Conveniently, the pump I used for the better part of my first two years of working with this fine oil would pull to a minimum of 3300 microns. I've even purged shatter for anywhere from 48-100 hours, with my vacuum pump continuously running. Not once did it nucleate good material, especially considering I almost always ran cold extractions (<33°F). It's not the best way to preserve a flavor profile (purging at 3300 micron), but I'll say some pretty tasty -and super smooth - dab has still been managed that way.

Gray Wolf said:

Clearly a bragging rights return. Judging from the cloudiness, some of that weight may be plant wax.

What temperature did you do the extractions at?

Click to expand...

For this reason, I would suggest separating the soaks into separate slabs....at least separate the first two from the last two, but I often recommend the first soak alone.

SH: You appear to have used Pyrex, and poured or scraped that onto parchment, correct? Not on silicone here?

Gray Wolf said:

Aroma, flavor, effect? Objective, but still the test of the pudding....

Click to expand...

I'm extremely slow at pulling descriptive language out of the air, but you're right I think that looking at it someone might think maybe $25/g (retail, here in SoCal,) but looks taint everything... so let me say it has a regal tone with a death stroke of power befitting it's name, Lil Dragon. Indica, but no old fogy couch lock dragon, a squire of an all day high flyer.

I used two cans of a clean lot of the original Puretane n-butane, the extraction was done using a Mason jar open at ambient, so the extraction temp was at the Bp of n-butane, 32F. The first soak pour off was the lightest yellow piss tint I've ever seen, any brighter and I could say electric.

That's a Corning ceramic dish with a Pyrex lid,

https://en.wikipedia.org/wiki/Evaporating_dish

I use Stator Bros generic parchment paper, which does have a silicone coating, just like most other brands out there.

Btw, I tried the silicone coated kitchen spatula, the oil adheres to it but lets go fully to a stickier material. I collected the remaining oil onto a SS spatula, extreme agitation, you guys wouldn't have included that part of the scrape with the rest out of fear of nucleation, ratted the heck out of it, and it just melted in with the rest of the patty. Go figure.

Which brings me to why I say 115F down to -29.5" Hg. It was 20,000 microns when I first started preaching this,

(3/6/'13 - SkyHighLer)

"ß-caryophyllene
Boiling point: 119*C / 246.2 degree Fahrenheit
Properties: Antiinflammatory, Cytoprotective (gastric mucosa), Antimalarial

http://en.wikipedia.org/wiki/Caryophyllene

seems to be the first to boil off, according to this info:
http://www.tokecity.com/forums/showthread.php?43587-Vac-Pump-Discussion-Thread&p=1227139#post1227139

Since caryophyllene starts to boil off before THC, I made a data table of some of it's boiling points under vacuum just like I presented for THC. What you want to do is stop pulling your vacuum at about the 20,000 micron level and keep your temps below about 120F. That way you'll still be boiling off the trapped butane and moisture, but leaving all the oil components intact and unstressed, and all you'll ever get is sap.....imo."

http://www.tokecity.com/forums/show...ssion-Thread&p=1294586&viewfull=1#post1294586


I noticed GW was saying 115F/-29.5" Hg in a thin film, and agreed that was a good stand.


As you can see from my micron meter readout, I don't go all the way down to -29.5" Hg (~10,000 microns as GW pointed out,) I stop at about the 20,000 micron level(-29.15" Hg) so I have plenty of room for overshoot. I recall seeing a low of about 13,000 microns this purge.


Interesting about the color, the trichs were clear (see pic,) so from the nice yellow first soak pour off, each subsequent pour off was still yellow or in the final pour off, clear. What I find interesting is just how green the butane/oil solution in the jar appears from the finely ground material, and that the 2.5 micron filter paper holds it all back.


One of my reasons for posting up is to counter the assertion that high cannabinoid strains often come out wax. Knock on wood it didn't happen to me, scrapping, agitation, what did I do differently?

Thanks again for the kind words!!

Thanks for the info been running everyday and not posting anything. My main problems were too low of heat, too long of purge time for the smaller amounts I'm doing, and scraping. I may try pulling a vac on my collection chamber after I recover most the butane and scrape then..
Here is some crumble that I scraped the next day after running for headstash. I was getting gooey mess sugar before this current light crumble awesomeness.

First is my old Tek, second is improved vac method but I still scraped collection chamber, third is crumble from hard scrape.

Going to check the oven to see if everything is warm it's been an hour since I put them in preheated oven.

Haha never came back to update this! Running all day so I will share my purge results

I started today by scraping the leftover from my last run. It was a indoor trim run with lots of small buds, strain was Bruce banner. It's been sitting a week or so in the open. Gonna do a purge on it to see if it comes out shatter or sugar or crumble. Just set it in the oven at 105 preheat. Turned the heat up to 115 and going to let the concentrate come to temp and pull a hard vac.

SkyHighLer said:

^ you don't know what you're missing...


I usually use my calibrated dial gauge to make sure I never go below -29.5" Hg, today I used the micron meter exclusively, and found it much easier to follow the pressure level.

$300/oz MMJ delivery nuggs, SCLab's found ~30% cannabinoids.

27.9g nuggs

9.90g product

35.5% return

~30/g for what I think is awesome oil, not too dark considering I ground the starting material, and soaked it four times in n-butane.


115F down to -29.5" Hg in a thin film, pulling several muffins, and when the bubbling slows way down it's done. Less than an hour in the vac chamber today. Stable shatter, it won't ever turn to wax.

Click to expand...

How do you grind? How dry is the bud?

Ground as in a metal herb grinder, a large two piece Cosmic. Must of been extremely dry to get that high of a return percentage, sorry I don't remember specifically.