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Author: Subject: Separating stuck ground glass joint
coyote
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[*] posted on 25-4-2023 at 08:17
Separating stuck ground glass joint


I have two 24/40 pieces of glassware stuck to eachother, and I have tried pulling them apart, twisting them, and heating up the outer one with my heat gun, but I've been unable to separate them. I tried getting some kind of liquid in the joint but nothing is permitting it.

Any ideas on how to get these unstuck?
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[*] posted on 25-4-2023 at 09:01


I have had some luck boiling them in a sodium carbonate base bath. Have a stopper stuck in a 100ml RBF at the moment and probably attempt to break it without screwing up the 24/29 joint on the flask.



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[*] posted on 25-4-2023 at 09:12


Quote: Originally posted by arkoma  
I have had some luck boiling them in a sodium carbonate base bath. Have a stopper stuck in a 100ml RBF at the moment and probably attempt to break it without screwing up the 24/29 joint on the flask.


Good idea, I'll try that and send an update when I get home from my classes.
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[*] posted on 25-4-2023 at 09:52


Wiggling the joint side to side (as if trying to bend at the joint) works much better than twisting.

A little WD40 helped me to un-freeze a joint.




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Clear_horizons_glass
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[*] posted on 25-4-2023 at 18:13


Running them through an annealing cycle. So ya need to put it in an oven or kiln and slowly heat it up to 1050F and then slowly cool it down.
If you can get the slightest drop of water in between the joints sometimes you can heat it up very slowly and the steam helps.
A Bunsen burner might be better at separating the joints that a heat gun. Start above the flame an inch or two and slowly work your way into the flame.




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[*] posted on 25-4-2023 at 18:49


Patience.


I have broken many stuck joints through being impatient. (I don't want to buy any more sep funnels for a while if I can help it.)
My last stuck joint was on a vacuum desiccator. I resisted the temptation to apply any significant force. When it did not come apart with a couple of taps with a wooden dowel I sprayed it liberally with WD40 and left it in a position where the oil would soak into the joint. Two days later it was still stuck. On the third day it came free with a finger-touch.

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shocked.gif posted on 28-4-2023 at 12:43


Update: I made an idiot move, I tried to force it open after getting wd40 in it, it cracked in my hand and cut it open.

Anyways, I'll just smash the rest of the glassware that's already broken to get it off
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[*] posted on 28-4-2023 at 13:07


Sorry for your loss. Rethink, reuse, recycle.
My broken glass gets cleaned, ground joints are cut off and annealed.
Unusable pieces are brough to red heat and tossed in a bucket of water to produce fritz material.
Its great as boiling stones. Tried a few times to make a filter fritz, always ends up cracking.
Manages to fuse a male joint to a test tube to make a long thermowell once. It works perty good




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[*] posted on 29-4-2023 at 12:26


Be careful.
Using force might actually work sometimes in this case. If there's an expensive apparatus involved, the cheaper part, like a stopper that's stuck, may be destroyed purposedly to get it off.
But it's very important to wear cut resistant safety gloves and protective goggles. It should be clear that broken glass is sharper than a razor and may cause horrible injuries.

It is very important to always grease the joints properly, especially if there are alkaline solutions involved or the tolerances of the ground joints are high (cheap glassware).

Ethanolic KOH is a good mixture to soak it in that might help. I also cleans the glassware nicely.
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[*] posted on 2-5-2023 at 09:30


The last I read, put pressure with fingers around the joint. The labglass makers are sadistic idiots??? from where get ideas to make the labware?? from his asshole?? :-D

now this people maybe start to wake up??

https://www.aliexpress.com/item/4000554896023.html?spm=a2g0o...

I ended in making my own "design", I searched a guy making labware and my flask are all the news with male joint. The stopper is a 50, 100 ml... female joint flask. if any problem, I put the "stopper" between two wood tables and with a dry impact the "stopper" is liberated. And now I can "froze" very hard the "stopper" because I can remove it no matter how hard is joined. I'm very happy, inclusive now for distillation too I buy male joints, and when all the olds broke never buy it again. With the same price!



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