Sciencemadness Discussion Board

Frozen Glass joint?

YT2095 - 5-10-2007 at 09:52

well I made out like a Bandit today in glassware and half of it I have no idea what it`s even for!
but the Kipps apparatus I have has a badly frozen ground glass joint as it`s been sitting on a shelf for several decades without being properly cleaned.

HOW do I get the thing apart?

brute force doesn`t seem to work, and I don`t want to break it.

evil_lurker - 5-10-2007 at 10:39

Try gentle heat from a heat gun first.

If that does not work, then send it off to a glassblower... its not worth ruining such an expensive and hard to find piece.

solo - 5-10-2007 at 11:01

Save your money use WD40 let it penetrate well and problem resolved......solo

woelen - 5-10-2007 at 11:27

Take a little WOODEN hammer (a toy hammer may also work). Wrap the stuck joint in thin tissue paper and carefully tap the joint, while someone else carefully tries to pull things apart. This works in many cases. But DO NOT use a metal hammer. That will break the delicate glass. A metal hammer is too heave.

chemrox - 5-10-2007 at 12:25

Have you tried running boiling hot water over the outer joint- just long enough to warm it but not heat the inner one?

This usually works for me- if it doesn't WD40 as the man said.

jam640 - 5-10-2007 at 12:39

If gentle heating doesn't work you may try applying a small amount of methanol which usually slowly soaks in between the glass and let's it loose.

evil_lurker - 5-10-2007 at 13:32

Actually I bet some stuff called Penetrating Blaster would work great.

Its similare to Liquid Wrench for getting nuts and bolts off, cept it works much better.

You can get it in Wally World or many fine auto parts shops.

12AX7 - 5-10-2007 at 17:30

I hear tell PBlaster is mostly ATF and lacquer thinner. WD40, likewise, is essentially mineral spirits; to be exact, it's a lot of stoddard solvent, plus a little oil which remains when the solvent dries.

Edit: among the organic laboratory, anything etherial (light alkanes, ethers, ketones, etc.) with something oily, waxy or fatty dissolved in it would probably suffice.

Tim

[Edited on 10-5-2007 by 12AX7]

Antwain - 6-10-2007 at 00:14

When I seized a joint (and cracked the attachment off a thermometor fitting) by heating with a MAPP torch I had to run through *many* WD40, heat, cool cycles to get it off. But I think I may have actually partly fused the joint so this may not be necessary for you.

Nicodem - 6-10-2007 at 02:12

Besides heating, beating with a wooden hammer and WD40, another thing that sometimes help is to dripping acetone/AcOH until it gets between the joints and then hammering/heating it. It sometimes works, especially on the alkali damaged joints. In other cases just about nothing helps. :(

YT2095 - 6-10-2007 at 02:29

well the WD didn`t even penetrate, the heating (Bunsen) didn`t help and bashing it on the bench (solid oak).
I did get a little WD to go in from the Other side (where the gas exists) using the WD40 pipe that comes with the can.
so I`ve got that sitting upside down now and keeping my fingers crossed.

I like the Acetone idea! that`s much less viscous and likely to get in.
there were Marble chips in there so it was probably last used for CO2 generation.

YT2095 - 6-10-2007 at 04:54

Gah!!!!

it Worked, and had a much better penetrating power, and Now I have them apart Finally thanks to that a plank of wood I shaped and a BFH!
sadly it`s bady cracked (the already cracked) separator between the liquid and solid stage, so I`ll need to blow a piece of glass or make from an already existing piece another separator (doesn`t seem to be That complicated), although it would have been nice to keep it as Original.

but at least it will now Work again! and hopefully have another 50+ years of use!


Thanks everyone for your help, I was about to half fill it with Fluorescien and just have it as an Ornament in the Living room :)

YT2095 - 6-10-2007 at 05:09

here`s the final result, the Blue wire btw, it simply to stop it re-joining again until I can get around to cleaning it properly:



this is the Broken bit, the crack at the top doesn`t show, but it IS cracked too:


Antwain - 6-10-2007 at 07:36

Thats a nice piece of equipment! :o

Ozone - 6-10-2007 at 20:10

Since it wasn't mentioned, I find that the old ultrasonic cleaner/bath (sometimes in a large beaker w/acetone in the bath) is enormously helpful with unfreezing ground glass joints.

Nice piece of glass!

Cheers,

O3

Antwain - 7-10-2007 at 00:39

Really? Ive seen glass shatter in an ultrasonic when it touched other glass :o

unionised - 7-10-2007 at 01:23

Nice Kipp's; I invite you to look into finding some teflon sleves for really important (ie expensive/ hard to replace) joints like that . I know you may know about them but others here might not and this seems like a good chance to tell them.

Ozone - 7-10-2007 at 06:16

Quote:
Originally posted by Antwain
Really? Ive seen glass shatter in an ultrasonic when it touched other glass :o


I have only seen this happen if the glass was already cracked. OTT, this seems to work fine. Usually, I'll just put the piece under water in the bath and let it go for an hour.

Beware though as in some cases the writing/graduations on the glass can be polished off.

Cheers,

O3

chemrox - 7-10-2007 at 19:16

so which technique finally worked? the WD40 or the acetone/AcOH?

YT2095 - 7-10-2007 at 22:36

it`s hard to say, when sprayed from the indie the WD did creep into the joint about 1/3 of the way, I cleaned all that away (as much as would come out) and then added the Acetone, GAA mix, that almost made it trough to other side in one or 2 places within a few minutes.
it still refused to shift, so I got a plank of wood (a floor board) and cut a `(` shape into it that fit the underside of the the joint, lay the whole thing down on packing plastic, grabbed the end with my feet and kept hitting it with a hammer and turning the kipps a little between each blow.
took about 30+ hits

hydride_shift - 13-1-2014 at 18:48

Quote: Originally posted by solo  
Save your money use WD40 let it penetrate well and problem resolved......solo


utfse saved the day

crazy thing that works

quantumchromodynamics - 13-1-2014 at 20:32

Before attempting the soaking methods, I promise this works almost every time, and is easy to do.

First face the joint forward and hold the receptacle firmly. Then with a little force, not much at all, just "tink" the joint back a few times with something like a butter knife. Then "tink" the joint from behind with the force directed forwards a few times. Finally, "tink" the joint from the left or right a few times, but not on both sides. Nine time out of ten, the joint just falls out.

I believe if the joint is nice and round the first two steps focuses the friction into two parallel lines, and the final step focuses the friction down to just two points.

It is a little freaky how well this little trick works.