Also, I haven't seen it done except online, and heard of it from a first-person view, BUT LN2 definitely will work as an extraction solvent.
The only thing left to purge is water. My question is, what's the return, what's the necessary eqpt. and cost, etc., safety?
Seems like an interesting alternative to butane, although it is not easy to buy lots of liquid nitrogen (I think...).

sky_blue said:

I believe you...although I am surprised.
If this dessicator/vacuum is safe then, and can hold a vacuum for an hour at a time without the pump on, ----here's the big question --- based on your knowledge, could you hard-wire a hotplate into the vacuum chamber so that you could maintain your sample at an even temp. for terpene retention, say 120F, for an entire hour, and it would be safe? I spoke to the owner of a company that makes vacuum chambers, explained some of the basics, and he laughed when talking about using these Bel-Art things. He may have been biased, but he said it was inferior for anything other than short vacuum times w/small samples w/NO heat. He said extended heat of even 120F would eventually compromise seals or various components of the chamber --- which would lead to failure... He also mentioned hearing of people using glass jars and creating their own vacuums, and then putting them in hotwater baths for extended periods (ala Youtube). He thought that was pure stupidity and dangerous.

If you think he's wrong, maybe I'll try one of these Bel-Arts...
Do you think all those things above combined will be safe?

Click to expand...

We use a Corning Scholar 170 hot plate in our glass dessicator, with a two stage vane pump. I ran the cord through a hole in the rubber stopper. The first setting is at about 115F and it works slick.

I would not recommend modifying the chamber with a heating pad. There are a few reasons for this:

1. Polypropylene and polycarbonate are a bitch to seal properly for vacuum applications after drilling them out--and these chambers are thin enough to make it an even bigger pain in the ass.

2. Heat can soften polypropylene and polycarbonate (although I believe the latter to a lesser degree).

3. There are better ways to do this and better products for it.


This product is for simple applications. When compared with a professional grade vacuum chamber MEANT SPECIFICALLY for degassing compounds--the capabilities certainly are laughable. However most products that fall into the "professional grade" group are super mega overkill for this purpose. These little dessicators work perfectly well for small samples.

If you want to do what you're saying--there are better ways to do it than hardwiring in a heat pad. For instance, pick up/build something like this:



And you can simply submerse that in a hot bath while you're purging

Hi, I agree w/everything you're writing. I know what eqpt. is safe and works, but it's a lot more expensive than a Bel-Art dessicator.
I am just surprised that people are doing what they do with heat combined with very flimsy looking vacuum chambers...

It will work so long as you don't heat the vessel itself, which is not necessary for this process.

it seems like i'm running into trouble with my vac purge..i do a hot water bath exchange between runs in the vac to help facilitate purging..but with a largish run..ounce or so, i'm finding that everytime i put it in the chamber or in the hot water bath (works better for me than a toaster oven) i still get bubbles...no mushrooms or anything, but sparks and bubbles...how long must i vac? seems like its been in there for more than 24hrs at a reasonable temp for purging..any ideas or tips from the more experienced?

Sky_Blue
Please add me or message me I am new on here but I have spent so much time reading all of what you guys have talked about because I have a "friend" that has been doing the BHO thing for short time now(year or so). It is funny to hear everything you guys are saying because its someting I have been thinking myself for a really long time now. I bought a polycarbonat dessicator a few months back to try this vacuum thing out but no way was I even going to think about heating that thing up and put it under vac. So I have been waiting for the right time to get somehting better and now i just ordered but it was also with a 3 CFM vac pump. It is A VERY basic Vacc should i reinvest in soimething like with a http://www.amazon.com/Dv-6e-Elimina...qid=1373213971&sr=1-3&keywords=jb+vacuum+pump or will I be fine with what i have?

I would play with what you already ordered before investing anymore money. My biggest concern with acrylic or polycarbonate topped chambers, is that it be thick enough to not fail under heat and high cyclic fatigue. If that happens, you can simply replace the lid from some place like Multi Craft or Tap Plastics.

The pump is small, but adequate to pull to the -29.5" Hg that you seek. The Just Better is a better pump, but also pretty spendy. We use a CPS VP6S at close to half the price.

I USE A CPS PUMP!