DMT-Nexus member
Posts: 113 Joined: 24-May-2011 Last visit: 29-Sep-2013 Location: Intn Waters
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I'm in the market for a vacuum pump, looking at pumps that can do 28" of vacuum. I'm going to be buchner filtering through qualantative paper, distilling under a mild vacuum, and whatever else a home chemist would do that I'm not aware of. Will 28" cut it? Thank you!
I understand that the micron rating is used for lab vacuum pumps, but that scale doesnt bear much reference to me.
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analytical chemist
   
Posts: 7463 Joined: 21-May-2008 Last visit: 03-Mar-2024 Location: the lab
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anything from 21-27" is fine for common tasks such as filtration; strong vac will suck material right through the filter paper. look for a diaphragm pump. "Nothing is true, everything is permitted." ~ hassan i sabbah
"Experiments are the only means of attaining knowledge at our disposal. The rest is poetry, imagination." -Max Planck
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No.. that can't be...
Posts: 493 Joined: 21-May-2010 Last visit: 04-May-2024 Location: The assylum
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I have used too strong a vacuum source during filtration and learned the hard way that you'll rip the filter paper. If you get a pump capable of a strong vacuum, then you will need to regulate the vacuum. Also I would suggest that you use a trap to avoid getting liquids in your pump. Everything mentioned herein has been deemed by our staff of expert psychiatrists to be the delusional rantings of a madman who has been treated with Thorazine who is hospitalized within the confines of our locked facility. This patient sometimes requires the application of 6 point leather restraints and electrodes at the temples to break his delusions. Therefore, take everything mentioned above with a grain of salt...
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DMT-Nexus member
Posts: 113 Joined: 24-May-2011 Last visit: 29-Sep-2013 Location: Intn Waters
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Right, I forgot about filter paper ripping. It will have a liquid trap. Thanks for the diaphram suggestion as well.
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Rennasauce Man
Posts: 853 Joined: 27-May-2011 Last visit: 25-Feb-2019 Location: A Pale Blue Dot orbiting a GV2 Yellow Dwarf fusion powered Luminous Ball of Plasma at 30km/s
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I purchased a 500ml filterflask with a rubber seal and a 70mm porcelain butchner funnel for 18.95 at http://www.agile-fx.com. Heres the link: http://www.agile-fx.com/...-Kit-w-fdsh--70mm/DetailI needed a vacuum pump to complete my filtering setup so i purchased this off ebay: http://cgi.ebay.com/ws/e...em&item=330337502331As far as i know, after lots of web browsing and searching this was the best deal for a filtering setup. I have no issues with this combo and it works very well for rue extractions. Esp. HCL manskes, was able to filter almost 6g of crystals with one filter paper. "let those who have talked to the elves, find each other and band together" -TMK
In a society in which nearly everybody is dominated by somebody else's mind or by a disembodied mind, it becomes increasingly difficult to learn the truth about the activities of governments and corporations, about the quality or value of products, or about the health of one's own place and economy.
In such a society, also, our private economies will depend less upon the private ownership of real, usable property, and more upon property that is institutional and abstract, beyond individual control, such as money, insurance policies, certificates of deposit, stocks, etc. And as our private economies become more abstract, the mutual, free helps and pleasures of family and community life will be supplanted by a kind of displaced citizenship and by commerce with impersonal and self-interested suppliers...
The great enemy of freedom is the alignment of political power with wealth. This alignment destroys the commonwealth - that is, the natural wealth of localities and the local economies of household, neighborhood, and community - and so destroys democracy, of which the commonwealth is the foundation and practical means.” - Wendell Berry
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DMT-Nexus member
Posts: 608 Joined: 07-Jun-2010 Last visit: 13-Feb-2018
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If you want a hand-powered vacuum pump the best you can find is from Mityvac (esp. the "silverline"  . To see the world in a grain of sand, and to see heaven in a wild flower, hold infinity in the palm of your hands, and eternity in an hour.
- William Blake
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DMT-Nexus member
Posts: 113 Joined: 24-May-2011 Last visit: 29-Sep-2013 Location: Intn Waters
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justine wrote:If you want a hand-powered vacuum pump the best you can find is from Mityvac (esp. the "silverline" . Already own one, thank you.
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analytical chemist
Posts: 7463 Joined: 21-May-2008 Last visit: 03-Mar-2024 Location: the lab
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hand-vac, as you can imagine, is limited to filtration. if you want to do other applications, such as vac-distillation, sublimation, and/or vac-desiccation, a diaphragm, rocking-piston, or rotary-vane pump is recommended. if you need to do distillation or sublimation of high-boiling compounds, you'll want a rotary-vane pump capable of pulling down to the low-micron range; check the specs.. CFM is not important in this context, absolute pressure is more important. "Nothing is true, everything is permitted." ~ hassan i sabbah
"Experiments are the only means of attaining knowledge at our disposal. The rest is poetry, imagination." -Max Planck
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