evil_lurker - 1-7-2007 at 18:05
Don't ya just hate them?
When working with low boiling point stuff with high partial vapor pressures in a closed apparatus... you think everything is all good then next thing
you know the stopper goes flying off and hits the ceiling. 
Ahhh the joys of working in the laboratory.
tito-o-mac - 6-7-2007 at 07:12
fit a bigger stopper? maybe try out a flask that has swrew on caps!
Ozone - 6-7-2007 at 16:51
Maybe not such a good idea!
Believe me, the stopper flying off can actually save your ass! I have had the side of a 2-L sep-funnel literally pop off (perfectly round piece of
glass) b/c I had inadvertantly frozen the ground glass stopper (and there must have been a small crack in my funnel). This was with diethyl ether at
~28°C.
I always try to avoid "closed-systems"... I like to use a mercury bubbler, manometer or relief valve to keep this stuff straight (a spontaneous
overpressure will give you bubbles, keep your mixture away from air and moisture, and save your precious glass!
And, erm, yes, I have had them hit the ceiling...then fall onto the apparatus and destroy it (heavy glass ones
).
Ever notice that stuff like this tends to happen when someone is watching?
Sucks,
O3
flyingbanana - 6-7-2007 at 20:05
makes me appreciate my goggles...imagine if it flew at your eyeballs! Always wear goggles!
bio2 - 6-7-2007 at 21:28
....."And, erm, yes, I have had them hit the ceiling...then fall onto the apparatus and destroy it (heavy glass ones"........
A kind of half ass relief valve can be had when using ground
glass pennyhead stoppers by inserting them loosely and tying
a piece of teflon string around them joined to the female joint with a little slack.
That will prevent the falling stopper hazard which is really dangerous. I had a real close call once and it scared the shit out of me contemplating
what could have happened.
For glass stoppers that you really want to stay put use
#18 solid copper wire with 3 or 4 wraps.
The_Davster - 8-7-2007 at 13:47
Cracked the lightbulb in the hood at work with one. I use ductape to secure them.
DrP - 9-7-2007 at 01:23
What about the little plastic clips you get for quick fit joints. They get used to keep stoppers on I think. Good thing is that if there was a really
big pressure increase, I think they would give, allowing the stopper to pop off or at least rise out of the joint a bit to release the pressure.
YT2095 - 9-7-2007 at 03:05
I`ve had it happen with a number 71 gas jar bung before when using my bubbler, you can plug the output and nothing happens for a while, then the pump
starts to change it`s sound then WHUP the bung bounces a good 4 inches.
not in it`self particularly dangerous unless you`re bubbling Cl2 or the likes.
tito-o-mac - 9-7-2007 at 05:51
How about the one which uses air pressure or suction to secure itself?
You could wear safety glasses or install a barrier of some sort.
tito-o-mac - 9-7-2007 at 05:54
You also try this out just for fun: take a bicycle pump, stuff a cork or stopper at one end and begin pumping. Soon after you will realise it's
getting harder and harder, until you come to a point where there is a short "whoosh" sound and the stopper propels about a good 3-5 metres