frozen/stuck ground glass joints?

Question

What is the best way to separate stuck joints without breaking anything? What is your favorite technique and why? Prevention would be best but that is out of my control.

Answer 1

Heat (heat gun) the female joint, which will cause it to expand, while cold (dry ice or liq N2) the male part, which will cause it to shrink. (although this sounds kinky it works) Tap the female end with a wooden block. The joint shoud un-stick.

Answer 2

Glass Joints

Answer 3

Prevention wise, best way is to use vacuum grease, sticky enough to hold together the glass joint and easy enought seperate. To tell you, I am best friends with you problem :-p i dont like heat becasue you can crack the glass, instead try twisting it apart if you can, Another trick I use is try to get some mineral oil into the joint to try and lube it up if that doesnt work, also if you must use heat, use running hot water, not the bunsen burner...

Answer 4

I let glycerine or water seep into the joints, yes it takes a few days but is effective. Remember that a twisting method is best when seperating. To answer the next question I use water when the material in the system is an aqueous, and glycerine when it is organic.

Answer 5

I usually use a heat gun for separation. Hot water works as well. For particularly hard cases I use a sonicator.

For prevention I would suggest Teflon joint sleeves if they can be incorporated into your budget. They last a long time, and they do not contaminate the things you work with like grease or oil.

The link is not to my choice vendor, but for illustration:
https://www.sciencelab.com/page/S/CTGY/23729

Good luck.

Answer 6

Try heating the joint. The expansion may help break the seal.

Answer 7

you're gonna have to knock it gently against the countertop. it might be enough to dislodge it. heat might also help.

i normally use force because it works 9/10 times