plante1999
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Ground glass quartz tube
Does anyone know where a tube, made of quartz and that have ground glass joint, is sold? A tube much like garage chemist one: http://www.sciencemadness.org/talk/viewthread.php?tid=10564
Thanks!
I never asked for this.
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Mixell
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They are usually done on demand, I'm also searching for one.
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Mailinmypocket
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Same here... I have a large quartz test tube but have had an impossibly difficult time finding a glass blower that does quartz/jointed connections.
I've gotten by with cramming glass wool tightly between the quartz and boro glass but its far from practical 
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Lambda-Eyde
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http://www.technicalglass.com/ - I'd estimate 25-40$ for a tube with a joint.
Edit: For a tube like GC uses in that thread, you'd obviously have to fork out more. Also keep in mind what he says about joints - a quartz female and
a borosilicate male will crack!
[Edited on 17-4-2013 by Lambda-Eyde]
This just in: 95,5 % of the world population lives outside the USA
Please drop by our IRC channel: #sciencemadness @ irc.efnet.org
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Magpie
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Here's a supplier of quartz tubing. They will also do glassblowing and ground glass joints. It may take some coaxing for small jobs, however.
http://www.quartz.com/quartz.html
The single most important condition for a successful synthesis is good mixing - Nicodem
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bahamuth
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Spherical joints will do the trick, joining borosilicate and quartz.
Any sufficiently advanced technology is indistinguishable from magic.
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garage chemist
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Even a quartz male and borosilicate female will crack- if they get hot and are left to cool while assembled. Such a combination must be disassembled
while still hot to avoid cracking, as I found out.
Only spherical joints are truly safe for combining quartz and borosilicate, although you can get away with conical joints if you follow the advice I
just gave.
Go to a university glassblower and ask whether he can make such a tube for you. Don't get put off by the price, I paid a bit more than EUR 100 for
mine. Custom made glassware has its price.
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Dr.Bob
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The company below is a quartz specialist, and is in NC, so ever better (for me.) I would call them for a quote. They are smaller and might even
work with individuals, but not sure.
Also, chemglass has made a few simple quartz items for me in the past, at reasonable prices.
http://prismresearchglass.com/
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turd
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Jeeez!
You are not talking about quartz. Fused silica a.k.a. fused quartz is - by definition - not quartz. Quartz glass is an oxymoron but
acceptable. Quartz is wrong - and not a single person in this thread got it right.
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Mixell
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The usually acceptable term is fused quartz.
Fused silica usually refers to this type of items: http://www.ebay.com/itm/Melting-Crucible-for-Gold-Silver-Bra...
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unionised
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"Only spherical joints are truly safe for combining quartz and borosilicate,"
Why?
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Hexavalent
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Perhaps due to differences in coefficients of expansion?
"Success is going from failure to failure without loss of enthusiasm." Winston Churchill
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watson.fawkes
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Yes. The thermal coefficients vary by a factor of
six.
Spherical joints are the not only joint geometries that are possible, merely the most common and standard ones. Flanged joints, with gasket and
retaining clamp, would work just as well.
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turd
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At least in the scientific literature that I'm aware of fused silica is generally translucent material used to make ampoules or other reaction
containers. And nobody I know uses these opaque silica crucibles - it's mostly Al2O3 if oxides are OK.
The distinction between fused quartz and fused silica is a bit silly - after all quartz is a form of silica and chances are high that what you call
fused silica is made from quartz sand. 
But all this is besides the point. The actual point is: whether you call it fused silica or fused quartz or quartz glass - it's bulk
amorphous SiO2, whereas quartz designates a set of crystalline SiO2 polymorphs. So don't call your tubes
quartz tubes, because every time you do god kills a kitten.
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Mixell
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Well, I'll need to in order to purchase some...
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unionised
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I know why you can't use a tapered joint with two different materials if their expansion coefficients don't match.
(and, incidentally, it's not the ratio of the expansions that matters so much as the difference)
What I'd like someone to explain is how a spherical (well, hemispherical really) joint will work any better.
They are useful in that you don't need to align them so carefully but, as far as I can tell, if the ball expands more than the socket then the socket
will snap and if the socket expands more than the ball then the joint will leak.
[Edited on 20-4-13 by unionised]
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turd
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???
I think I didn't get my point across:
"fused quartz tube" = good.
"quartz tube" = just wrong.
If a vendor uses the latter I would not trust him - he doesn't know what he's selling.
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watson.fawkes
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Quote: Originally posted by turd  | "fused quartz tube" = good.
"quartz tube" = just wrong.
If a vendor uses the latter I would not trust him - he doesn't know what he's selling. |
Well, given that some
old-line vendors aren't pedantic about repeated the word "fused" everywhere, I don't see why there such a need to be pedantic about it here. All these
vendors say "fused quartz" sometimes and just "quartz" sometimes.
National Scientific Company, whose URL is quartz.com.
Precision Electronic Glass
GM Associates
These vendors all appear on the ASGS Buyer's Guide page (the ASGS is The American Scientific Glassblowers Society); it was a handy place from which to pull a number of examples.
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Fleaker
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I have about 300 quartz tubes that I bought and were the wrong size. They're 26X30 mm Heraeus (basically their version of GE214). Each is 1200 mm or
so in length. $20/a piece.
Neither flask nor beaker.
"Kid, you don't even know just what you don't know. "
--The Dark Lord Sauron
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plante1999
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Do you mean they are oval? Are they ground quartz(ground glass)?
I never asked for this.
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Morgan
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He means 2mm wall thickness. That's a lot of quartz tubing to buy and the wrong size. And I thought I bought a lot buying 3 boxes (15 per box) Heraeus
quartz tubes just because they were cheap and I like materials science. Quartz has so many good qualities.
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Mixell
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The price is good, but it will probably be a hassle to ship.
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unionised
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I'd still like too know why Garage Chemist thinks spherical joints are OK with mis-matched expansion coefficients.
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turd
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| Quote: Originally posted by watson.fawkes | | Well, given that some old-line vendors aren't pedantic about repeated the word "fused" everywhere, I don't see why there such a need to be pedantic
about it here. |
If it is pedantic not to designate things with words that have a completely different meaning then I will take it as a compliment. Also this must be
one of the worst appeal to authority arguments ever. If at least you would have bothered to find something in the scientific literature. For me it is
like calling hydrochloric acid "HCL": Do it once it's a typo, do it consistently you're an ignorant, be proud about your ignorance and you're a
"kewl". Unfortunately the standard enforced in the organic chemistry subforum is not maintained for other topics.
| Quote: | | I'd still like too know why Garage Chemist thinks spherical joints are OK with mis-matched expansion coefficients. |
I suppose the idea is that the force of expansion is not only exerted in transversal direction leading to wedging and consequently breaking but also
in longitudinal direction leading to a sliding apart.
In any case I don't buy the problem. The real solution is to not heat the joints. I know a group that does *many* evacuated fused silica ampoules, the
last part of a tube being molten ~2-5 cm from the joint. Due to the low thermal conductivity the only breaking of joints was during cleaning. And no,
the remaining tubes are not removed while still hot. I've seen a few of these setups and never anything but conical joints. The fused silica is always
male, of course.
The same people regularly do reactions in a fused silica tube in a tube furnace typically at 1100°C under vacuum, H2 and Ar and not once in several
years a joint has broken. If your joints break you are doing something wrong or your glass is of bad quality.
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