Vacuum Pump discussion/questions

[Jnugg]

So I've dabbled in makin BHO a few times,no major runs,just the SS turkey baster with steel mesh screen and unbleached coffee filters,14-15g runs,blasting outdoors away from any and all ignition sources,hot water purge blah blah blah.


I'm interested in doing larger runs (1/4 pound) and want to do it right and use a vacuum pump and vacuum chamber to purge any leftover butane and moisture from the oil.

I've read a bit about these vacuum pumps (single/dual stage).Some sources say you don't need a single stage,other sources say a 2 stage is better.

I recently watched a youtube video by knotty where he uses a 2 stage pump on one ProVac chamber and a single stage pump on another,side by side.The single stage pump was much louder than the 2 stage pump,and I couldn't really tell but it looked like they pulled full vacuum in the same amount of time.

I have read a bit about vacuum pumps and their cfm ratings.If I understand correctly,a larger pump only pulls full vacuum faster than a smaller pump on the same size vacuum chambers.I have also read about the micron level in regards to vacuum pumps and BHO.I read that ideally,one would want a pump that can vac down to 10-25 microns.

So to start my questions off...

1) Are 2 stage pumps quiter than single stage pumps?

2) Is it necessary to have a pump that can vac down to 10-25 microns?

2a) What difference in the final product would there be with a pump that gets down to 25 microns vs 75 microns?

3) What are the main differences,and,pro's/con's of single stage vs 2 stage vacuum pumps?

I know alot of people say to stay away from Harbour Freight but I've been looking through them and these are some pumps I've come up with...

1) Pittsburgh Automotive 2.5 cfm 2 stage Vacuum pump pulls to 75 microns $99

2) Pittsburgh Automotive 3 cfm 2 stage vacuum pump pulls to 22.5s (whatever s means) $139

3) U.S. General 3 cfm 2 stage vacuum pump pulls down to 25 microns $139

4) Pittsburgh Automotive 3 cfm 2 stage vacuum pump pulls down to 22.5 microns $139

 

[Primalraindrop]

I have the harbor frieght vacuum pump. I bought it used. my buddy used it for 6 month running it everyday all day. and it works great still for me. Just my personal experience tho im sure others have had other experiences.

 

[Gray Wolf]

Both a single stage and a dual stage will pull to a lower vacuum level than is required and can actually boil away your cannabinoids at room temperature.

My single stage is quieter and faster than our dual stage, and smokes less.

 

[frankenstein2]

You can get a hand held manual vacuum pump at the auto supply store. They are used for bleeding brakes. It worked for me and is a lot less expensive than the electric pumps. Maybe next year I can afford a vac oven or whatever new toy they have for purging bho. Till then my little hand pump can bring the pressure to -25hg so that's good enough for me.

 

[Gray Wolf]

You can get a hand held manual vacuum pump at the auto supply store. They are used for bleeding brakes. It worked for me and is a lot less expensive than the electric pumps. Maybe next year I can afford a vac oven or whatever new toy they have for purging bho. Till then my little hand pump can bring the pressure to -25hg so that's good enough for me.

The fish trap exists only because of the fish. If you have your fish, your trap is adequate.

Old engineering axiom. If it is stupid and it works, it is not stupid.

On the other hand, much of what we use an electric vacuum pump for, would require that you have wrists like most peoples necks, to keep at it hour after hour, and alas then there is the specter of repetitive motion diseases.

There is also age. I have extra large front paws and milked cows growing up, so in my glory could make giants amongst grown men cry without effort shaking hands, but as the years fly by, so has my ability to even open some jars without tapping on the lids first to loosen them.

With bionic knees on my hind legs, instead of racing up and down the stairs in wind sprints, I now take the elevator too, so my point is that everyones needs and abilities are not only different, they are constantly changing and there is room for more than one solution, because one size doesn't fit all.

 

[Jnugg]

So is the full vacuum (micron) not an important detail?And according to that chart I don't want to pull down farther than -29.8" HG/1000 microns (29.88" HG/1000 microns boiling point of THC @ this vacuum is 111.2°F) so I should be good with a vacuum pump that pulls down between 29.14" HG/20,000 microns and 29.88" HG/1000 microns?

Which of the pumps I listed would you recommend GreyWolf?

 

[SkyHighLer]

So is the full vacuum (micron) not an important detail?And according to that chart I don't want to pull down farther than -29.8" HG/1000 microns (29.88" HG/1000 microns boiling point of THC @ this vacuum is 111.2°F) so I should be good with a vacuum pump that pulls down between 29.14" HG/20,000 microns and 29.88" HG/1000 microns?

Which of the pumps I listed would you recommend GreyWolf?

You understand, thank you! That chart was for THC, here's the chart for the first of the known good components of your oil to boil off, http://skunkpharmresearch.com/cannabinoid-info/

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


"Caryophyllene is one of the chemical compounds that contributes to the spiciness of black pepper."
http://en.wikipedia.org/wiki/Caryophyllene

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.
Below is the data for some of the boiling points of ß-caryophyllene under vacuum, hence the rule of thumb, 115F @ -29.5" Hg

 

[Gray Wolf]

So is the full vacuum (micron) not an important detail?And according to that chart I don't want to pull down farther than -29.8" HG/1000 microns (29.88" HG/1000 microns boiling point of THC @ this vacuum is 111.2°F) so I should be good with a vacuum pump that pulls down between 29.14" HG/20,000 microns and 29.88" HG/1000 microns?

Which of the pumps I listed would you recommend GreyWolf?

Sorry, not familiar with any of them, but note that they are all two stage.

For a cheap pump, we like our CPS VP6S enough after four or five years, to get a second one.

 

[G.O. Joe]

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

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.
Below is the data for some of the boiling points of ß-caryophyllene under vacuum, hence the rule of thumb, 115F @ -29.5" Hg

The boiling point you're looking for is right on the page.

129-130 °C (14 mm Hg)

14 mm. is 0.55" Hg.

 

[SkyHighLer]

The boiling point you're looking for is right on the page.

129-130 °C (14 mm Hg)

14 mm. is 0.55" Hg.

Enthalpy of Vaporization: 48.6±0.8 kJ/mol

Boiling Point: 268.4±10.0 °C at 760 mmHg

http://www.chemspider.com/Chemical-Structure.4444848.html

?

 

[G.O. Joe]

?

Yes, physics works nicely in this case. 268.4 was their ACD/Labs prediction, their EPISuite prediction is closer to pre-vacuum era numbers. From a 1902 thesis -

 

[SkyHighLer]

Here's my experiences, thinking, and feelings concerning deep vacuum purges of BHO.

If I vacuum purge at 115F down to -29.5" Hg until it won't bubble up anymore (usually about an hour with a thin film,) I can then get further bubbling if I take the vacuum below -29.5" Hg @ 115F. My thinking is nearly all, if not all of the butane and moisture has been purged at 115F down to -29.5" Hg, and the bubbles produce by taking the vacuum down further at the same temperature are something else...

Another thing is I never see what looks like portions of my BHO getting cloudy like it's turning to wax as I've seen in many pictures of BHO that has been vacuumed all the way down.

I have a year's worth of my BHO extractions sealed up in the fridge, and none has changed consistency (gone to wax.)

 

[G.O. Joe]

Maybe a $15 aspirator and an airtight metal box is all you need. You might be able to tell what's coming off at high vacuum by making a trap. Maybe something like hardware store HVAC copper tubing (it's very clean) in 1/2 or 3/8 depending on your pump inlet, a foot or two of that submerged in LN2 or a slush of dry ice and acetone, letting the tube warm (does a flammable gas come out of one end if the other is sealed?) before running a little acetone through it and evaporating that. The lighter components (which caryophyllene isn't) will evaporate first, these often have a stronger and more desirable smell than heavier molecules.

 

[Jnugg]

Well I'm looking to make wax/honeycomb,and maybe dabble in trying to make shatter,but I'm loving the wax/honeycomb that's going around in my area right now.Super clean and shipped in frim the Bay area and Colorado.


So any pump that gets me to -29.5" HG will be good enough?

 

[SkyHighLer]

Well I'm looking to make wax/honeycomb,and maybe dabble in trying to make shatter,but I'm loving the wax/honeycomb that's going around in my area right now.Super clean and shipped in frim the Bay area and Colorado.


So any pump that gets me to -29.5" HG will be good enough?

Guys say they get by not even being able to go that low... using a Mityvac hand vacuum pump, or a faucet aspirator vacuum pump, or a vacuum bag sealer vacuum pump, etc., but even the Harbor Freight vacuum pumps work ok, and everything above them in quality work pretty darn well from what I've read at the forums, there's no word out not to buy any specific brand or model because it sucks.
So yeah, get any rotary vane vacuum pump that appeals to you in your budget, as they'll all get you to a very deep vacuum, eventually, just keep in mind a higher CFM pump will evacuate a large chamber quicker. Amazon usually offers free shipping.

 

[Jnugg]

Bump for more input/further discussion.

 

[Sirdabsalot46n2]

Hello Jnugg.

New poster, long time lurker...
Thought I'd share my experience with my Vacuum pump.

The Harbor Freight Pittsburgh model, single stage 75µ pump is adequate for your purpose.
And for an additional 10-15$ buys a 2 year replacement warranty.

Your pump breaks down, simply bring it to your local Harbor Freight and you get a new one in the box, no questions asked.

I've used mine many times already and it's not very loud at all, she will peg my gauge in under 45 seconds, and only cost me 100$ out the door (with the always available 20% off on-line coupon.)

As pointed out by GW &SkyHigh...too deep of a vacuum will indeed hinder the extract, via boiling away volatile terps, particularly the lighter polyterpenes at room temp.

 

[Jnugg]

Thanks for the info sirdabsalot.I'm either going with the HF 2.5 cfm 75 micron single stage or the HF 3 cfm 25 micron 2 stage pump.Still not sure as I'm looking into other pumps like FJC and Robinair.

Thinking about getting a 3 gallon 10" x 10" ProVac vacuum chamber or a Best Value Vacs tall 1.5 gallon vacuum chamber.

 

[Jnugg]

Also I plan on having a friend that blows glass make me a 38mm ID x 18" to 24" extraction tube.

I want to make wax/honeycomb and figured to do so,blast through the extractor into a pyrex casserole dish,place in hot water bath for initial heat purge,then scrape and collect on to either a slick pad or parchment paper,lightly whip (not much) and place into vac chamber doing a mix of heated vac purges and non heated vac purges like FarmerJohn420 on youtube.

Does that sound about right and do you have any info/details/comments/tips about making wax/honeycomb?

I will dabble with making shatter too at a later time.

 

[Sirdabsalot46n2]

Good Afternoon Jnugg.
You are most welcome my new friend!

I am very pleased to lend some advice.
First and foremost.....
Vac-it Pro vacuum chambers are not worth your hard earned cash. The lid they use is known to crack, and you will most likely have to teflon tape all their connections and reinforce all hose connections.

However, Best Value Vacs is the bees knees.

Haven't heard any negative reviews from their products, and they include a solid polycarbonate 1” lid.

I actually am familiar with Farmer John, and his tech is solid...

I started out doing the hot water bath myself, but now I use sand in a deep dish griddle.

Sand conducts and disperses heat very efficiently and doesn't evaporate, eliminating the need to change your hot water every 10 minutes.
Using sand also reduces the propensity to pull atmospheric moisture into your oil from the steam that derives from the hot water.

I suggest pulling to around -15 hg for your first pull and releasing, then slowly increase your pull until you hit your full vac.

This will ultimately conserve your terpenes, and lessen the chance of over-muffin in the chamber.

Which brings me to another tip.
Make sure to line your chamber with parchment, along the bottom and up the walls of the vessel.. An oil muffin can expand from it's original size immensely.

It can be a real mess if you are not prepared.

Let me know if you have any other questions.
That is about all I can think of right now, but oil is always on my mind in one way or another, do I may drop back by and throw some more advice at you.

Much respect,
Sir dabs.