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Author: Subject: Lab Stands + Questions
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[*] posted on 28-11-2019 at 08:16


Quote: Originally posted by Yttrium2  
Could I use 1 stand to hold up a distillation apparatus?


Unless it's one of the beefiest, heavy and sturdy stands ever with similar quality clamps etc., I'm gonna say - no, it's not worth the risk.
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Yttrium2
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[*] posted on 29-11-2019 at 11:25


Is the best way to setup the stands is having 1 clamp above the boiling flask and 1 clamp above the reviewing flask?

I see some pictures showing the condenser being supported by a special clamp and the reviewing flask hanging or touching the bottom.


What is this condenser clamp called? A condenser clamp?


How do you support your distillation apparatus?
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[*] posted on 29-11-2019 at 14:53


Because I don't know where to clamp, I'm also confused on what type of clamps I'll need. It's been a while since I've had a distillation setup, and I'm wanting to get everything planned in advance.


Can someone help me with a good cheap type of clamp I'll need to support my distillation unit?
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[*] posted on 29-11-2019 at 15:49


It is good practice to clamp the flask at the neck and have the heat source on a lab jack (or brick). That way you can drop the heat in an instant if required.
I also clamp tall items: columns and addition funnels. I also clamp the condenser at the middle for stability. So, typically 2-3 clamps per distillation and I use 2 of the rods on my rack.

Of course you can use fewer clamps and stands. But it comes at a cost to flexability, safety and the ability to make quick changes. I have used a short path straight from a rbf in a mantle with no clamps. But stability is a feature that is always desirable.
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draculic acid69
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[*] posted on 29-11-2019 at 18:46


On eBay there's plenty of bossclamps,ring clamps,etc,etc you just happened to pick the smallest cheapest one that isn't big enough for anything but test tubes.spend a bit more and get bigger better ones.
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[*] posted on 30-11-2019 at 12:07


Quote: Originally posted by draculic acid69  
On eBay there's plenty of bossclamps,ring clamps,etc,etc you just happened to pick the smallest cheapest one that isn't big enough for anything but test tubes.spend a bit more and get bigger better ones.


I didn't purchase it.

I know of 1 clamp that will work for holding a condenser, but I'm unsure about the other ones.


Any recommendations for an inexpensive clamp that can hold a liebig
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[*] posted on 30-11-2019 at 21:55


Type "laboratory clamps eBay" into Google.
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[*] posted on 1-12-2019 at 04:37


I have tried a few types of clamp;

small three prong, cheap, good for holding thermometer in beaker etc.
3finger small.jpg - 82kB

cheap large clamp, ok for columns and condensers
2finger large.jpg - 41kB

large three prong, good for flasks, columns and condensers
3finger large.jpg - 103kB

large four finger, my favourite, good for flasks, columns and condensers
sometimes not as convenient for holding flasks as the three prong above
4finger large.jpg - 100kB

none of the above are perfect, but all are usable.




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[*] posted on 1-12-2019 at 06:46


Quote: Originally posted by Sulaiman  
I have tried a few types of clamp...


Now they look more the part IMO - sturdy enough to comfortably use, but cheap enough to afford - where are they from? They the kind of thing one can find on the 'bay etc.?
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[*] posted on 1-12-2019 at 07:10


The four photo's above are copied from current eBay uk listings as I have no usable photo's of my own equipment.



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[*] posted on 1-12-2019 at 15:41


Quote: Originally posted by Sulaiman  
I have tried a few types of clamp;

small three prong, cheap, good for holding thermometer in beaker etc.


cheap large clamp, ok for columns and condensers


large three prong, good for flasks, columns and condensers


large four finger, my favourite, good for flasks, columns and condensers
sometimes not as convenient for holding flasks as the three prong above
.


Below is more detail to the above comments:

The first clamp: the one I purchased broke at the base of the single finger with mild tightening of the clamp wing nut, probably due to the weak and brittle (not tough) diecast material and the stress raising point at the base of the finger caused by the abrupt change in dimensions (not smoothly evolving in to the base). Yes it probably can clamp a thermometer but sooner or later you will use too much clamping force and the finger will snap off.

The second clamp: the one I purchase, the clamp on either side was made of sheet steel certainly tough enough to resist the force I could apply with my fingers to the wing nut. There is no bushing between the clamping screw and the fingers so the threads tend to jam on the punched hole in finger and play at both ends can cause the clamping force to suddenly relax. The parallel clamp make it unreliable for for clamping anything other than parallel sided equipment. The plastic covering the clamps is low friction so useless unless the equipment has rim to stop it sliding out. Its a cheap option and if your careful usable. You may need to bend the fingers to get them to more uniformly clamp and a rim is needed on anything heavy to stop it sliding out.

The last two clamps are designed well. Both have good fitting bushings on the clamping screws and smooth transition to the bases. The rubber and cork are excellent clamping friction and the cork will not melt. The three pronged unit is excellent for clamping none parallel sided items such as the tapered outer surface of females joints. The four pronged unit is ideal for parallel sided items but with additional packed anything can be clamped.
Both are excellent but tend to be several times the price of the first two.

For the low cost option buy the second item and adjust the sheet metal finger for better clamping and add extra packing if needed.


[Edited on 12/1/2019 by wg48temp9]




i am wg48 but not on my usual pc hence the temp handle.
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[*] posted on 1-12-2019 at 21:51


I bought a few of the first kind of clamps and they're barely big enough for anything bigger than a test tube.even a 24/29 joint is it's absolute maximum size it can open to.
When it comes to lab clamps and stands cheap means tiny.
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[*] posted on 11-12-2019 at 17:20


I was thinking of going with this deal, it seems to be phenomenal for the price. But it's getting aot of bad rap for some reason in the reviews

https://www.amazon.com/Support-Stand-Coated-Base-Size/dp/B07...


What are some thoughts on this one ^


Also, I have seen distillation apparatuses commonly held up with 1 clamp on the condenser, can anyone comment on setting up like this?

I'm still having difficulties figuring out which stands to buy and what clamps, I really hate having to reorder them

[Edited on 12/12/2019 by Yttrium2]
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[*] posted on 11-12-2019 at 17:56


The reviews indicate the base does not sit flat and is light weight. Seems very unstable. This is backed up by it being 1.5 kg total weight, which is on the light side. I would steer clear.
Have you looked for second hand ones on eBay?

[Edited on 12-12-2019 by B(a)P]
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[*] posted on 11-12-2019 at 19:01


The base of the stand in the above discussion looks like sheet metal. Essentially a rectangular box with no bottom so its weight must be small compared to a solid cast base. However it could be filled in with cement easily or even better if you have a cheap source of lead fill it with that.

The plastic feet look like they are a push fit on the sheet metal of the box sides which means the height could be easily adjusted by filing down the box edge to make each foot sit on a flat surface. Yes that's moding something just purchased but a stand with a solid cast iron base is likely to cost much more.





i am wg48 but not on my usual pc hence the temp handle.
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