Guest - 5-9-2014 at 16:57
I'm trying to find somewhere to buy a water aspirator for vacuum filtration and vacuum distillation, so far on google I've only found 2 and they were
going for $100+ which seems to be a touch rich!
Can someone point me to where I can buy them and inform me of what I should look for and avoid? I've never used them before so any and all information
will be helpful 
.
elementcollector1 - 5-9-2014 at 17:11
Well, for starters, unless you have a really good water pump, be prepared to waste a whole lot of water to get any decent vacuum.
Second, they can be found on Amazon for about $20, and somebody else probably knows a cheaper source.
Third - just invest in a vacuum pump. Less maintenance, better performance.
Dr.Bob - 5-9-2014 at 18:36
I have a few odd water aspirators left for $5 plus postage, as well as I just traded some glassware for a small diaphragm vacuum pump that would be
good for small vacuum needs. It would cost more, but does not need water. It is an KNF UN 840 FTP 220 watt, 110 volts, just like this one below,
only I would take less than that guy. I have been meaning to list it soon, but this reminded me.
http://www.ebay.com/itm/KNF-LABOPORT-N840-FT-18-Diaphragm-Va...
Texium - 5-9-2014 at 18:53
I'd recommend a hand vacuum pump if you're on a budget. It's not quite as fast as an aspirator, but it wastes no water and doesn't cost much. I'm
happy with mine. Of course, I'd definitely prefer to have a real vacuum pump.
Guest - 5-9-2014 at 23:25
Thanks guys, I've found a couple of places selling them from links i've found in other threads here and am waiting to hear back about postage costs
since it seems impossible to find them even mentioned locally. Dr.Bob I inboxed you about the ones you have .
I was thinking to minimise water wastage I could set up a recirculating system using a 50lt or even a 200lt drum with ice for cooling, looking at some
other threads here I'm beginning to see it might not be as easy as I first imagined and I have some learning to do concerning pumps and how these
aspirators function. The hand vacuum pump looks like it could be useful for vacuum filtration but how practical would it be for vacuum distillation?
One day I might have the spare funds for a proper lab vacuum pump but at the moment they seem to be FAR outside of my budget.
Texium - 6-9-2014 at 07:17
I used my hand vacuum pump for vacuum distillation once and it worked great. Also, if you get one, it would probably be good to try and find a fritted
glass Büchner funnel for vacuum filtrations, because when you use a normal Büchner funnel with the hand pump, you have to pump constantly, but the
fritted glass ones will allow a vacuum to build up in the flask and continuously pull the liquid through so you can leave it alone for a while. I have
the fritted kind at home, and never noticed the problem with using it with the normal kind until I brought it to school yesterday and used it with a
normal one.
macckone - 6-9-2014 at 08:45
Waterbed stores carry aspirator pumps for draining the waterbeds.
They will give about 20ft of lift with tap water pressure and flow.
Higher flow and colder water will give better results.
Templar - 7-9-2014 at 01:42
get a cheap single or dual rotary vane vacuum pump from china used for refrigeration!
They are surprisingly tough! Just change the oil if you run anything nasty though it like a lot of HCl vapours and get a gas washing bottle full of
carbonate to clean acid gasses.
zenosx - 10-9-2014 at 17:38
I just purchased a new nickel aspirator to replace my nalgene one (that had it's back-flow valve destroyed by NO2 fumes) for $18 on amazon. Unless you
are looking to use a water pump that should be the top to pay. I use an outlet in my basement with Teflon piping to the lab with several valves along
the way. I don't have a gauge to measure vacuum yet but it gets the job done
Metacelsus - 11-9-2014 at 08:30
My aspirator pulls 28 in Hg maximum (measured with a vacuum gauge). I expect yours should be about the same.
[Edited on 11-9-2014 by Cheddite Cheese]
zenosx - 12-9-2014 at 18:55
I need to get a gauge and have yet to do the calculations, but my new nickel aspirator will boil water at 34 C, W/E that equates to. I've got too many
exams to have much lab time atm!