Dirt Cheap Harbor Freight Vacuum Pump

[t00fatt]

I'm not looking to spend too much on a vac setup, and was looking at hand pumps to get started with when I came across this pump. It's dirt cheap and supposedly rated for 28.3" of mercury. Does anyone have any experience or heard about this pump? I hope to use it just to get most of the air out of the chamber, then use a hand pump to get it down closer to where I'd like.



http://www.harborfreight.com/air-vacuum-pump-with-r134a-and-r12-connectors-96677.html

EDIT: Oh and I am aware the pump is pneumatic, and I have a compressor to power it.

 

[vaporonly]

i'm not sure the google searching to do but I have run across people using this device that like it provided your compressor can supply the required CFM. this is a very simple device, not much to go wrong or fail on it...

what are you using for a chamber?

 

[t00fatt]

Yeah my compressor can certainly handle the load. I have yet to make my chamber, I'm planning to use a small stainless pot with 1" polycarb sheet on the top where I'll attach my vac line and gauge. Yeah I looked more into the pump, and seems to work similarly to how a diffusion pump works but much more simply and with air rather than oil. I am defiantly going to give this pump a try, it's exactly what I'm looking for. Thanks!

 

[Doug]

Let us know how it works out. I would utilize a vacuum system if I knew how and it was relatively inexpensive. This sounds like half of it at least.

 

[OF]

Yeah I looked more into the pump, and seems to work similarly to how a diffusion pump works but much more simply and with air rather than oil.

No, I don't think that's the case at all. The text tells it, "The air vacuum pump is a venturi-type AC pump that eliminates moisture...". It's the extreme case of the Bernoulli Principle....the thing that makes airplanes fly:
http://en.wikipedia.org/wiki/Bernoulli's_principle

Think about the feed on a spray paint gun or perfume atomizer. Or for those old enough to remember 'Flit guns'? 28.3 is really a pathetic vacuum and to do that will need LOTS and LOTS of air (the bulk of the unit is a muffler......).

DPs are something else entirely different. They condense the free gas above the 'pot' so the MP (Mechanical Pump) can pull it out the foreline. Here we have everything we need for that except the heat, working fluid, foreline and MP. Oh, yeah, and a solid (low militorr) vacuum to start.

Worth a try, but I wouldn't hold my breath.....I'd plug my ears.....

OF

 

[t00fatt]

When it was explained to me, wrongfully obviously, I was under the impression diffusion pumps did operate with a venturi effect, but used a high velocity stream of oil to create the low pressure. Well that is neither here nor there really. My apologies?

A lot of reviewers report pulling 30" with compressors similar to mine. I am aware the pump is sub-optimal, and will take quite a bit of effort to get to work; hence my comparison to a hand pump rather than an electric pump. I would love to be able to afford a $100-$150 pump right now, but that unfortunately is not possible. My only connection for concentrates, which used to get shipped in from the west coast, is no more to say the least. My desire to start making my own concentrates before I can afford it is not one out of ignorance but instead utter desperation. I'd love to wait and save up for proper gear, but that will have to wait. Thanks for the advice though.