Cheap Vacuum Purger

Yes, I forgot those, the waxes...that's why wintterizing is a good idea, always Can vac all you want, waxes will stay put...

So is the jury still out on the mityvac hand pump?

I drip my liquid gas into 99% alcohol, and let it sit in the sun with a plastic box over it to keep out the bird poop etc...

no bubbles...

then at night I roll the blob into a tubular form and lay it horizontally on an inclined sheet of slick rubber stuff...
in hours it drapes and spreads out, then i fold it over and keep doing that ...

I think vacuum purging may be a fable to make you more reliant on the clubs etc. ..
the only diff i can see is the "amber glass" is much easier to handle.. and amber...

oh, and to answer your q. I vote not sufficient vacuum number achieved by the mightyvac to do what ever it is they think vacuum purging does.
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I haven't seen this suggested anywhere, and there may be good reasons not to use this method that I do not know about, so please do say so if there's something I've overlooked...

How about (for a bit of a ghetto setup) using a freezer/fridge vacuum pump as a basis for a cheap vac setup? A couple of valves, chambers - and if you're worried about running constantly you could set up with a vacuum switch/relay.

This is a commonly used setup for vacuum bagging epoxy resins in the radio controlled aircraft world. I imagine that for BHO setups (I'm very new to this, so it's all theory-craft to me) you want a quick drop to ~28/29mmHg? In which case the valves and chambers are important.

I've done this myself with the intention of vacuum bagging some foam wings but never got round to it - they easily pull a full vacuum, and with a relatively small investment you can put together a relatively "potent" vacuum system.

Anyhow, just throwing it out there...

curious to hear more about this

Well, as with any ghetto setup you can simplify or complexify your system according to your ability to invest or improvise, but a basic setup is like what's shown in this instructable:

http://www.instructables.com/id/Making-A-Fridge-Compressor-Into-A-Vacuum-Pump/

The main money spent will be on a gauge (if you think it's required, these pumps pull right up to 28mmHg so you may not feel the need for one) tubing and a switchbox/electrics so as not to have a straight mains cable going into the pump.

When I put my system together (currently disassembled in a box somewhere, else I'd post some pics) I had an electronic adjustable vacuum switch tied to a 12/240v relay along with the gauge on a ballast chamber so I could adjust the level of vacuum accordingly, but this isn't really needed here.

e: here's a pic of the vac chamber at least:



From what I've read up on since posting, I don't think a quick drop to vacuum is required, so even a chamber and tap aren't needed for a really basic setup, just the main vacuum chamber, hose and a pump.

I hope I'm helping out here and not muddying the waters further, but this has been a standard cheap way of getting a vacuum in other hobbies I've been interested in, and it seems like a pretty decent solution here too.

Oh, and one thing to be careful of - the tennis ball over the outlet that the guy shows in the instructable is essential. Otherwise fine mineral oil mist is sprayed out of the outlet.

are vac pumps really only for butane extractions? or are heads using them to purge QWET and QWISO?

As I understand QWISO runs benefit from vacuum purging possibly as much as BHO, though like I said, I'm new to this... Planning on doing my first run this weekend if I get the time, and I'll break out the vac setup if I decide it's worth it.