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Author: Subject: Glass tubes
Yttrium2
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shocked.gif posted on 22-7-2019 at 15:31
Glass tubes


Again I have to ask about glass tubes -- the use of them for making flasks/apparatus and the useage of glass tubes so one can put together a simple still with an Erlenmeyer and a stopper.


This way no lab stand is needed
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j_sum1
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[*] posted on 22-7-2019 at 16:42


Well, I would not trade my distillation kit for plain glass tubing. My first condenser was a broken burette with a PVC water jacket. It won't get used again.

Things to condiser:
Not all glass is equal. Glass tubing tends to be reasonably thin and fragile and have a low softening temperature.
Seals -- ground glass is a lot less temporamental than rubber stoppers. And it does not introduce impurities into what you are doing.
Configurations - the advantage of a kit and lab stand is that you can remove the heat easily. Good luck doing that with a free-standing Erlenmeyer.
Convenience. Bowing and bending glass is an art form. Looks easy but very easy to mess up. If you don't need to, then why?
Cost -- a distillation kit is quite frankly cheap in the big picture. I know guys who spend the same on a fishing rod or a single car tyre or football jersey or... We are all penny-pinchers in this hobby. But getting good glassware is a game-changer. Plain glass tubing is not that cheap in my experience. The difference might not be that great.

On the other hand, if you want to make something specialised for a specific purpose: maybe a system for disilling solvents from the tin or a dedicated methanol to formaldehyde rig, then a bit of glass bending might be just the thing. But we can't aswer that for you.




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XeonTheMGPony
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[*] posted on 22-7-2019 at 19:09


https://www.ebay.ca/itm/Pyrex-Glass-Tube-L-300MM-Outer-Diame...

it takes allot of time and skill to get good at it, this is how I used to do all my gas generators and such, wrapping stoppers in teflon to protect against nitric and chlorine and the like.

All sorts of borosilicate tubing out there to use.

The link is the stuff I ordered to make some immersion K type probes for thermal static reactions

[Edited on 23-7-2019 by XeonTheMGPony]
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j_sum1
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[*] posted on 22-7-2019 at 21:48


One other thing: lab stands are ridiculously priced if you buy them online. But there are so many other ways to do it. Wood was used for many years and it would not take too much to make something using some dowel and some blocks of wood. Or, if you can find some steel rod, embed it in some wood, or weld to a steel block or bury in a container of wet concrete. The rack in my lab is made from nickel-plated drawer handles screwed onto some timber and bolted to the wall.
Boss heads and clamps are harder. I have decided to go for genuine lab equipment. But it is possible to rig something acceptable from wood: depending on your skill set.




If you are interested, take a look at the latest offering from sum_lab:
A primer on metals and non-metals with at least one novel experiment.
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[*] posted on 23-7-2019 at 03:43


To fabricate anything other than a bent connecting tube you need to use borosilicate glass as soda glass does not like thermal shocks or thermal gradients.

With a propain/air torch you can bend a borosilicate tube and even seal a borosilicate test tube by crimping it. Anything more and you need a propain/oxygen torch. You can just about get by with a mapp/air torch.

So unless you really want to get in to glass blowing just for the fun then pre-made glass apparatus from China or used will be cheaper than buying/renting the oxygen, regulator, fancy torch and graphite tools to fabricate you own and you still have to buy the glass and then practice, practice a lot.





i am wg48 but not on my usual pc hence the temp handle.
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[*] posted on 23-7-2019 at 19:34


If you want a very hot torch that uses air instead of pure oxygen, there is this.
https://www.homedepot.ca/product/bernzomatic-ts8000kc-max-he...

It is a Bernzomatic TS8000KC Max Heat Torch Kit.
Using propane, I was just barely able to melt some copper, about 5 g.
Using propene, I was very easily able to melt the same amount of copper.

So, if you want to melt borosilicate, go with that model torch which can exceed 1100 °C.




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Yttrium2
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[*] posted on 26-7-2019 at 11:18


Reason I ask is because it gets to be a pain buying distillation gear / toting it around. Then of course it needs the municipal hookups

I just need to do a simple distillation, preferably out in the woods.

That is all I need it for, I'm thinking that if I don't need a large amount of glassware, than I shouldn't have it. It keeps costs low, it's easier to transport ect...


All I really need is an Erlenmeyer flask, a stir rod, a pipette maybe 1 more thing...

It keeps it minimal



[Edited on 7/26/2019 by Yttrium2]

[Edited on 7/26/2019 by Yttrium2]
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Yttrium2
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[*] posted on 26-7-2019 at 11:23


When people distill straight from the tin, as I have seen done before, doesn't the distillation pipe heat up and provide less condensation?


Could poly tube be used for distillation if it's long enough?

Also, any advice as to where to find EPDM stoppers besides the cane ends?



[Edited on 7/26/2019 by Yttrium2]
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draculic acid69
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[*] posted on 26-7-2019 at 18:21


As for poly tube maybe alcohol or water would be ok not great but ok as long as it's only used in the condenser a new not the gooseneck maybe.anything else and I doubt it will stand up to it.as for using wood I've used 1inch pine cubes to make bossclamps
it worked fine for lightweight stuff.just use a drill press to drill a 12mm hole vertically and then another one horizontally and and then drill a hole with a 2mm bit for the screws.it works.wouldnt use it to hold a five litre full of liquid but it worked well for one litre flasks.So wood definitely has a use in the lab.as far as using Dowel as lab stand poles it would probably work better than the mild steel rods I was using.fyi they bend don't use them.

[Edited on 27-7-2019 by draculic acid69]
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[*] posted on 27-7-2019 at 02:05


You can easily do a setup with boro glass and they make it in all diameters from 3mm inside to 12mm and larger. You can also get 1mm to 2mm walls. YOu just have to search on ebay or aliexpress. I found 10mm OD x 6mmID and 300mm (about 12") and got 15 pieces delivered to the US for $16-17.

I used 2 regular propane torches to join the pieces together to make longer tubes. It was incredibly easy, I thought it would be harder. I suggest sacrificing one piece and cutting it into 4 pieces (file & snap) and then practice joining them. You will probably end up with a useable piece and it won't be a sacrifice, just slightly shorter.

You can even flare the glass.

What about using a copper coil? is the substance reactive with copper? The larger inner diameter the slower the gas passing through, though the more expensive. Depending on how much your solvent or distallate costs, it is probably better to go with copper and distill slow enough to not over heat the coil. 25 ft of 3/8" is reasonably priced, or maybe 50ft of 1/4"ID, IDK which would cool more efficiently.
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[*] posted on 27-7-2019 at 03:42


In UK I bought various pieces of borosilicate glass tubing, not all for chemistry.
Initially I ordered the lengths that I wanted,
but later found that the tubing was in standard lengths of 1.5m,
anything shorter cost more as the supplier had to cut it.


I tried two 1.5m lengths of 16mm o.d. 9mm i.d. as an air condenser for the distillation of ethanol,
ok for a low rate of production but at full hotplate power (1.5 kW) it was almost useless.
As an emergency measure I put towels over the glass and kept the towels wet.

Even 10mm copper tubing needs many metres to work as an air condenser with performance equal to a single water cooled condenser.

If you are mostly interested in ethanol distillation I suggest that you have a look here https://homedistiller.org/




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