conducter - 4-5-2007 at 14:36
i have a brand new 125mL 19/22 seperatory funnel.
Now the valve for it is also made from glass and ground glass. Most of the ones ive seen use Teflon, am i suppose to use Visine or some other
lubricant when i use this for seperating chemicals?
not_important - 4-5-2007 at 15:43
yes :
http://www.sas.org/E-Bulletin/2002-09-20/labNotesCoyne/body....
search for stopcock grease with google or whatever.
Simple greases can dissolve in solvents, a little care in use is required. An older lab methods textbook should have a section on all of this.
Before fluorocarbons researchers would sometimes use a mixture of bentonite clay and glycerol or syrupy phosphoric acid as a lubricant on stopcocks.
Those liquids will not dissolve in many organic solvents, and the clay will form a gel with water.
[Edited on 4-5-2007 by not_important]
dedalus - 4-5-2007 at 16:34
Oh, man. Be careful. Get some good silicone grease and use it. Ground glass joints will freeze up, esp. if you get some alkali in them, and they
become, like FUSED.
conducter - 4-5-2007 at 17:25
how bout dow corning grease? I believe i read that that is the best of the best.
roamingnome - 5-5-2007 at 09:45
hahha
i felt like you when i snaged my china dual 1 liters, so proud of them
but your glass joint and nut wont brake down like the non-teflon screw that was holding the teflon stopcock snug.
some funky solvent just split the nut in two, leaking stuff all over the place.
i assume they are millimeter threads and should be easy to tap but dam