Sciencemadness Discussion Board

Equipment Sources

franklyn - 25-1-2008 at 13:22

If you can't find it on E-bay

try -

A directory of mainly used equipment dealers and suppliers grouped by catagory
even some worldwide. Click on the heading and scroll down to see the listings.
A cursory examination of the chemical equipment section uncovered two outfits
that have available lab glassware at what seems to me to be reasonable prices.
They're not giving it away, but at least you know what you're getting.


franklyn - 22-8-2008 at 18:46

Found this site that has basic labware at reasonable cost


bfesser - 22-8-2008 at 19:05

Has anyone tried the vacuum aspirator that Mountain Home Biological is offering I already have two glass Kimax aspirators, but for that price I'm tempted to test it against them.

[Edited on 8/22/08 by bfesser]

Phosphor-ing - 23-8-2008 at 23:03

It says for low vacuum applications so don't expect it to be very durable

appetsbud - 26-8-2008 at 06:24

some of that glasswear appears to be bomex, i don't own any, but i have heard some bad things about its chemical and thermal shock resistivity on these boards, should be fine for holding and pouring things etc, maybe just shy away from the high vacuum and temperatures.

bfesser - 30-9-2008 at 16:29

So, I decided to buy one of the aspirators along with some of their rubber tubing, the sink adapter, and the hose adapter.

I like the sink and hose adapter combination. They work better than my previous adapter setup which consisted of 4 solid brass adapters in a stack just to get from the sink threads to a hose barb.

The tubing is crap, as expected for the price. It works well enough for the high pressure water going into the aspirator, and well enough for the vacuum the aspirator produces, but would not be suitable for any other aspirator.

As for the aspirator, spend your money elsewhere. It's an interesting design and looks cool, but doesn't work very well. It produces a weak vacuum--not good enough for any real vacuum filtration or other common operations. On the bright side, it needs lower pressure and a lower flow-rate to produce suction than my kimax aspirators. I'd advise anyone to spend a little bit more to get an aspirator that actually works from elsewhere.

By the way, I highly recommend the kimax aspirators, if you can get one.

[Edited on 9/30/08 by bfesser]

undead_alchemist - 30-9-2008 at 20:42

There were two types of Bomex glassware.

The ones that were sold by VEE GEE Scientific, were custom made for them and were much heavier.
and the standard Bomex glassware, much thinner.

Also note. Kimble glassworks bought Bomex glass. so you may find some Kimex glass that is made in China, is realy Bomex.

iHME - 29-10-2008 at 13:22

Why must all those good suppliers be US based? :(
I spent one day 6 hours googling of a proper European glassware vendor, only to find big corporations that are either US based or don't sell to individuals.
I'll probably get a business name soon.

So do you know any good European glassware vendors with reasonable prices?
Or even US ones with reasonable shipping charges for shipping to EU?

[Edited on 29-10-2008 by iHME]

Klute - 30-10-2008 at 09:11


iHME - 31-10-2008 at 10:14

We'll see. I just ordered a catalog from them.

watson.fawkes - 31-10-2008 at 12:34

Originally posted by iHME
Why must all those good suppliers be US based? :(
Kavalier Glass Works, based in the Czech Republic, is the maker of Simax brand borosilicate glass. Their "export" link is broken, but I'm sure that contacting them directly would be fruitful.

They also make household glass. Insofar as I can tell, most of it is still borosilicate, unlike Pyrex. It's unclear whether all of it is, but most of it's rated to 300° C.

Aspirator difficulties

Funkerman23 - 20-6-2013 at 21:48

I don't know what is wrong but I'm beginning to think aspirators are a load of it. A few months back I bought a pair of glass aspirators from Pellet lab ( scroll down) I figured what they heck and they have the red rubber tubing I far it hasn't cooperated. Now I have been trying to use a 50 to 80 gallons per hour pump from lowes but even at 130V AC I get about enough suction to tickle my finger. Ice water didn't help either. in short ; what am I doing wrong? should I try a larger pump? If a larger pump is needed what would be the safe maximum flow rate for a glass aspirator? should I find a metal or plastic aspirator? that Harbor Freight single stage pump looks better and better..

starman - 20-6-2013 at 22:20

Have you got decent pressure on the mains? Try it just off the tap.It is my impression that you need at least 40psi for good operation.Once I had a steel venturi hooked up to a grundfos CR2,low flow rate but running at 200psi.Spectacular performance.

Dr.Bob - 21-6-2013 at 06:15

I think most aspirators need a good 2-5 gallons per minute to work. So 60 gallons per hour will not provide enough flow. Connect it to a sink and flow as fast as you can and test the vacuum. Glass ones should be able to take a pretty good flow. Just connect it with Tygon or rubber tubing, it will pop off before the glass breaks, unless you clamp it really well. They are really best for short bursts of vacuum, where the waste of water does not matter much. If you need a vacuum for more than a few minutes at a time, then you need a vacuum pump of some sort, but there are many inexpensive sources of those listed in places on this forum.

bfesser - 21-6-2013 at 07:15

Quote: Originally posted by Funkerman23  
I don't know what is wrong but I'm beginning to think aspirators are a load of it. A few months back I bought a pair of glass aspirators from Pellet lab ( scroll down) I figured what they heck and they have the red rubber tubing I like.

I have aspirators from many different sources, including one from I'm sorry to inform you, but the <strong>Mountain Home Biological aspirators are just plain shit. DO NOT BUY THEM!</strong> I suppose I should have a posted warning to members earlier, but it entirely slipped my mind. I'm not sure if they all have this problem, but mine had a small hole between the upper and lower chamber (beside the nozzle). This allowed high pressure from the upper chamber to flow into the lower 'low pressure' chamber. They're defective, and the design is just plain garbage regardless.

I'm lucky enough to own two <a href="" target="_blank">proper glass aspirators</a> <img src="../scipics/_ext.png" /> (Kimble-Kontes), a <a href="" target="_blank">metal aspirator</a> <img src="../scipics/_ext.png" /> (Humboldt), a <a href="" target="_blank">Nalgene&reg; polypropylene aspirator</a> <img src="../scipics/_ext.png" />, and a handful (perhaps a dozen) of generic plastic aspirators from a <a href="" target="_blank">local surplus shop</a> <img src="../scipics/_ext.png" /> (95¢ each! and work as well as the Nalgene). Of these, <strong>I recommend the <a href="" target="_blank">Nalgene&reg;</a> <img src="../scipics/_wiki.png" /> aspirators</strong>, as it's easy to disassemble for cleaning, is resistant to most chemical vapors, is nearly unbreakable, and isn't prohibitively expensive.

[Edited on 7/9/13 by bfesser]

Funkerman23 - 21-6-2013 at 22:55

I feel relieved actually.. I thought something wasn't right but I didn't really know where or who( can't often blame the equipment and it be true).. I may still tinker here and there with them( or sell them as baubles) but I think a pump would be better overall after the above advice. I can't thank you kind folks enough for the help.

bfesser - 22-6-2013 at 08:08

I had considered trying to patch the hole in mine by introducing a small globule of 2-part epoxy into the hole using a syringe and flexible tubing, but then realized I had other aspirators and that it wasn't worth the effort.

Where are you located, by the way?

Funkerman23 - 22-6-2013 at 09:47

well for a general area answer I in Georgia ( US)but for Finer details I'd rather PM folks. I don't mind sending that to anyone asking but not on the open board.

bfesser - 4-7-2013 at 18:12

Quote: Originally posted by bfesser  
I suppose I should have a posted warning to members earlier, but it entirely slipped my mind.

Ahh! I did <a href="viewthread.php?tid=9834#pid137517">post</a>! I am truly losing my mind...
[sorry for the thread-rez]

Funkerman23 - 4-7-2013 at 18:48

I ran across that one using the search engine here once but I ( erroneously) thought that no longer applied given the date. My error in assuming they improved them. I like their red rubber tubing for my condenser lines but for anything serious I dunno. It fits on 7mm to 11 mm barbs well and that I like. but I admit it probably wouldn't work for corrosives all that well. the Kimax & Aldrich glass aspirators look great but given that they are a bit scarce ATM, I don't have a pond pump strong enough to feed one, and that I'm doing more( or trying to do more) vacuum distillation I'm pretty sure I need a pump for my needs( example: working with high boiling hydrocarbons, trying to make fuel from lubricants and other similar pursuits)

[Edited on 5-7-2013 by Funkerman23]

testimento - 6-7-2013 at 09:58

Common aspirator needs about 3.5 bars min. with cold water to generate 32mbar vacuum, this can be lowered yet still as far as maybe 5-10mbar, but this will already need pressures of maybe a hundred bars and hydraulic aspirator. My mains give 10 liters a minute or 600 liters an hour with full load. I prefer using 12-bar 12-volt driven circulator pump to save water: its not expensive for quickies, about 6-10 bucks a ton, but if you run an 8-hour vacuum fractionation every other day, you shit bricks when the water corp. beats your mailbox. The 12-bar pump can generate about 15-20mbar vacuum. I also have commercial vacuum pump with 500µbar lower limit and a 2kW improvised turbopump with the com.pump as a secondary stage that can generate high vacuum. Never used though, had no need to distill stuff like sodium or mercury, and all common chemicals, including sulfuric acid, tend to come through even the ballast chamber because of radically lowered boiling point.

Ive got the decipted 32mbar with mains water line. If you have got leaks in your system, even small ones, your flow rate needs to be equally larger, an ideal vacuum system with zero leaks could be driven with only few liters per hour at needle-aspirator, but even a small difference in vapor pressures of distilled materials would cause the vacuum to crush if one doesn't have large compensation tank which is put between the receiver flask and the aspirator. I have used 20-liter SS container as a vacuum reserve to compensate quick pressure swings.

About those water pumps. There are two types of pumps, other are for transfering water at low heights, and they can move substantial amounts of liquids, a small pump can easily go for 6 tons per hour, but they generate virtually no pressure. Then there are these rather small volume but high pressure pumps what we are looking for. The cheap ones go for 3-6 bars, the quite sensible priced ones anything between 6-20 bars and then the high pressure pumps like found in pressure washers that can be quite pricy.

[Edited on 6-7-2013 by testimento]