Sulaiman
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Ground Joint Soda Glassware
Two days ago I ordered a couple of small glassware parts via eBay and I just looked at them again,
one item now looks like I should have read the description more carefully
https://www.ebay.co.uk/itm/14mm-Female-to-18mm-Male-Expander... fsAAOSwhpZaQKN0
as it seems that the glassware is intended for some kind of drug taking pipe, so is only made of soda lime glass.
If my suspicion is true then using this with my borosilicate kit could be a false economy 
Any opinions as to whether this piece is borosilicate or not ?
CAUTION : Hobby Chemist, not Professional or even Amateur
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JJay
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It's probably borosilicate, but I wouldn't use one of those with labware. When I see drug paraphernalia listed with the labware on eBay, I report it
if it clogs up the search listings. Sometimes I send a scathing diatribe to the seller.
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unionised
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This sort of thing might help.
https://www.exploratorium.edu/snacks/disappearing-glass-rods
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LearnedAmateur
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Yeah they’re for bongs/water pipes (sorry if I’m not supposed to use those terms here), I wouldn’t class it as drug paraphernalia in itself but
14.5 and 18.8mm are the two joint sizes typically used for this purpose. Since the adapters aren’t directly heated, and considering the cost, I’d
go with it being soda lime.
I’d purchased a $0.99 14/23 male-male adapter for use in chemistry, for a cheapskate Dean-Stark setup in the synthesis of p-toluenesulphonic acid,
and it does the job just fine for a fraction of the cost of purpose made glassware. The trade off being that the joints aren’t overly precise and
tend to wobble, being about 1-2mm out, so if you’re concerned with leaking gases then it’s probably best to avoid it and just spend out a little
more for the borosilicate options.
In chemistry, sometimes the solution is the problem.
It’s been a while, but I’m not dead! Updated 7/1/2020. Shout out to Aga, we got along well.
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Dr.Bob
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Not sure what use this would even have for real lab glassware, since it's hard to tell if the joints are standard tapers. Maybe it would work for
14/22 and 19/22, but not at all clear. There are other Chinese vendors with real lab glass for not much more, I would stick to the better stuff,
only a small difference in price.
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LearnedAmateur
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Quote: Originally posted by Dr.Bob  | | Not sure what use this would even have for real lab glassware, since it's hard to tell if the joints are standard tapers. Maybe it would work for
14/22 and 19/22, but not at all clear. |
Yes they use the standard tapers, I’d also bought a cheapie 14.5-18.8 adapter, just the other way around to the one in question since I had a small
job lot of 19/23 RBFs. The only variations being, IME, the length of the joint so it could either protrude past or stop before the connecting joint
terminates on the fused end. Regarding the last point however, I’ve had this occur with purpose built QuickFit glassware, the most prominent one
being between a sintered glass funnel and a 24/29-14/23 adapter (somewhere in the range of 5-10mm), so it’s not a big issue unless a perfect fit is
absolutely required.
In chemistry, sometimes the solution is the problem.
It’s been a while, but I’m not dead! Updated 7/1/2020. Shout out to Aga, we got along well.
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Sulaiman
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Even though I can't resist cheap stuff, I assumed that the adapter was borosilicate when I ordered it,
I'll do the glycerol refractive index check (thanks unionised)
... if not borosilicate then I'll bin it to avoid future problems.
I just wanted an opinion on the glass type
and to warn others of the potential problem
as this is the first time I've come accross non-borosilicate ground joint technical glassware.
CAUTION : Hobby Chemist, not Professional or even Amateur
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NEMO-Chemistry
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| Quote: Originally posted by Sulaiman | Even though I can't resist cheap stuff, I assumed that the adapter was borosilicate when I ordered it,
I'll do the glycerol refractive index check (thanks unionised)
... if not borosilicate then I'll bin it to avoid future problems.
I just wanted an opinion on the glass type
and to warn others of the potential problem
as this is the first time I've come accross non-borosilicate ground joint technical glassware. |
I also got some of these recently. they freeze up lab glass joints really easy.
The ground finish on mine was very bad
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Sulaiman
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The adapter arrived today,
I put it in a beaker together with vegetable oil and a GG17 (borosilicate) adapter,
both adapters 'dissapeared' almost completely but not quite,
the new adapter seems to have a refractive index VERY close to borosilicate glass.
CAUTION : Hobby Chemist, not Professional or even Amateur
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wg48
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| Quote: Originally posted by Sulaiman | The adapter arrived today,
I put it in a beaker together with vegetable oil and a GG17 (borosilicate) adapter,
both adapters 'dissapeared' almost completely but not quite,
the new adapter seems to have a refractive index VERY close to borosilicate glass. |
I suggest you also put soda glass in as a comparision.
You may also be interested in this:
Another scheme which works is to make up a solvent solution (16 parts of methanol and 84 parts of benzene) which has a refractive index of 1.474.
Borosilicate glass has the same index value.
from: A Simple Method of Distinguishing Borosilicate and Soda Lime Glass pubs.acs.org/doi/pdf/10.1021/ed056p692 by WH Brown - 1979
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draculic acid69
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All bongs and glass smokeware are pyrex.sodalime glass would crack when heated and cooled.it is definitely borosilicate.its the same glass your flasks
are made of.
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