purge temps... and technique clarification

[qaxx]

Quick question. I know the absolute amber requires a thin-film purge after the ethanol wash. For straight BHO (no ethanol), do you also need a thin-film purge? Or can you purge in a smaller vessel?

 

[Gray Wolf]

Quick question. I know the absolute amber requires a thin-film purge after the ethanol wash. For straight BHO (no ethanol), do you also need a thin-film purge? Or can you purge in a smaller vessel?

The thinner the film, the faster the purge.

If we make wax, instead of shatter, we use thicker films and longer purge times.

 

[SkyHighLer]

Unless it is certified as an explosion proof device, I wouldn't use a hotplate for purging the initial pool of butane. Just warm tap water works, so it also isn't necessary to have an active heat source.

If you are using it under your vacuum chamber, the issue I found with our old stirring hotplate, is that it had poor temperature control in the lower ranges that we work at. Don't know about the one pictured, but I would find out before plunking down that much money.

A stirring hot plate that we've tested that does have rock steady temperature control in the ranges that we run, is the CAT Scientific MCS 66. I will be posting a thread on it soon.

Laboratory hot plates, been there done that...glad to hear the new ones finally have decent temperature control, but you're still going to have lousy surface to surface contact as most stock pots, pyrex dishes, etc, do not have a flat plane for an outside bottom surface.

Heat mats, if you provide cushy insulation under them will usually conform to these uneven surfaces to provide maximum energy transfer. Low wattage heat mats seem to me safe to use under a butane evaporating dish, provided any controls are either completely solid state, sealed air tight, or located away from butane vapors.

 

[rb extractors]

I stop my pulls at -29.5" Hg by closing the inline ball valve when the dial gauge reads where I know -29.5" Hg should be...and how do I know that?

Your Bourdon dial gauges reference ambient pressure to provide a reading http://en.wikipedia.org/wiki/Bourdon_gauge#Bourdon they will be off by about one inch of mercury for every thousand feet of elevation above sea level. Some have an adjustment screw, but the scale will never be really correct unless at sea level imo.
So, how to calibrate your dial gauge? I have a Yellow Jacket 69075 electronic micron meter to find the real vacuum levels and made a little table that tells me when my dial gauge reads -xx.x" Hg it's actually -xy.x" Hg.
Here's another free way to calibrate your dial gauge,
https://www.icmag.com/ic/showpost.php?p=5869373&postcount=76
Some additional notes on that proceedure,
https://www.icmag.com/ic/showthread.php?p=6058486#post6058486

thank you!

 

[Gray Wolf]

Laboratory hot plates, been there done that...glad to hear the new ones finally have decent temperature control, but you're still going to have lousy surface to surface contact as most stock pots, pyrex dishes, etc, do not have a flat plane for an outside bottom surface.

Heat mats, if you provide cushy insulation under them will usually conform to these uneven surfaces to provide maximum energy transfer. Low wattage heat mats seem to me safe to use under a butane evaporating dish, provided any controls are either completely solid state, sealed air tight, or located away from butane vapors.

Yeah, good point, our Briskheat mats work well and our controls are all solid state. With a Type K thermocouple and a Mypin PID controller, I can hold within two degrees of set point.

The thing that blew me away about the CAT hotplate, is that it didn't vary even 0.1 degrees for two days. It sat dead nuts on 46C, without every dropping to 45.9F or raising to 46.1F.

 

[keifsweat]

once the oil is put in the vacuum chamber how long from that point does it take to be fully purged

 

[MEMED]

A million years, starting once it hits 29.5" hg

 

[keifsweat]

Lol