mabuse_
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Registered: 3-6-2010
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Improvised vacuum for suction filtering - how about central locking pumps?
Hi,
I just got the equipment for suction filtering together, all but the most important thing - a pump...
Now I don't want to waste much water and i cannot work next to the nearest watertap.
I've got absolutely no experience with that - how much evacuation do i need just for effective workling with the buchner?
Some people seem to work even with penis enlarger pumps. Have you ever tried central locking pumps, or some other ghetto style improvised devices?
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Hexavalent
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Location: Wales, UK
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I have had excellent experiences previously with car air compressors that run off a 12V source.
The really cheap ones just use a piston and barrel system, and when you open up the case, there is a little hole on the top of the piston chamber to
allow the air in. Just glue a plastic or brass hose barb/nipple over the hole, add some thick tubing, drill a hole in the top of the case, push the
tubing through, put the case back together again and you're done. I've built several of these over my time, and each one has worked perfectly. Quite
an acceptable vacuum is created with little fluctuation that is more than adequate for vacuum filtration in my experience, using 250ml buchner flasks
and smaller Hirsch funnels.
On each one, I also cut off the normal car cigarette lighter adapter and replace the ends with banana plugs, which fit perfectly into my lab power
supply set at 12V DC.
I can't measure the exact vacuum strength as I don't have a gauge, but again it is more than satisfactory and the entire thing cost me less than £5
(I got the unit from HomeBargains, it comes in a little blue box and they have loads of them) and a few hours (and overnight for the superglue to dry)
to build. The normal tubing that comes off the compressor side can even be cut off and used as vacuum tubing as it is very thick. . . .or, you can
leave it on and use separate tubing for the vacuum side. The compressor/air blower is also great, when attached to a glass pipette or similar, for
blowing air across a solution to make it evaporate faster.
****
Here is the main unit I bought from HomeBargains for about £3.99
"Success is going from failure to failure without loss of enthusiasm." Winston Churchill
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mabuse_
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Thank you. I'll try it with the car compressor for the price one can't do much wrong
Though I believe the vacuum door lock system to have a stronger vacuum, the mechanics driven by them are sometimes very tight. But they aren't as
cheap.
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S.C. Wack
bibliomaster
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Location: Cornworld, Central USA
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But you don't want strong vacuum really, unless maybe you're filtering sludge through Celite over glass wool, where it would cause no harm to the
filter.
A $22.50 old style steel hand pump is also perfectly fine when aspirators aren't of use and there aren't acid vapors.
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