Sciencemadness Discussion Board

Falsely marked 24/40?

pip - 26-2-2009 at 11:55

this liebig I won at auction doesn't look right. I think the bottom is 24/40 only if so why? (I havn't recived it these pics are from the seller)

snapshot-117.jpg - 44kB

kclo4 - 26-2-2009 at 16:01

Only one way to find out I guess?
If it is not you can always buy an adapter or jimmy-rig it so it works with the rest of your set-ups. This could be easy to do depending on what you have, and what chemicals you plan on using with it.

ordenblitz - 26-2-2009 at 17:11

Looks to me like the joint was formed but not ground.

DJF90 - 26-2-2009 at 17:14

It looks like a clear-fit joint, but definately not 24/40. I dont even think it would be a 24/29... But so long as its a "24" joint it should still work with the rest of your setup, only your 24/40 cones will not go right in, however I dont think this is a problem as a good seal should still be made.

pip - 26-2-2009 at 18:29

there is no question the bottom is 24/40 but why would they make one that only has the bottom joint as 24/40?

so you guys think that first cm or so is ground and good enough?

evil_lurker - 26-2-2009 at 18:56

My guess is that it is a 24/25 half length joint. I've seen them a couple times used primarily on cows and certain resin reaction flask tops.

It is also highly possible that is a repaired joint.

As to why it appears not ground... well it could be that there was a PTFE sleeve being used, some residual grease or who knows...

[Edited on 26-2-2009 by evil_lurker]

smuv - 26-2-2009 at 19:31

That looks about like a 24/40 joint to me, it is possible that it was used for some special setup such as the distillation of diazomethane, where ground glass should not be used.

chemrox - 26-2-2009 at 19:32

Repair or release from poor Q/C. You could send it to a glassblower and have a 24/40 put on it. If you got it on ebay send it back.

querjek - 26-2-2009 at 19:43

I once got a liebig like that from a flea market... 24/40 joints will fit in it enough, but make sure you grease it and use a clip or stand or something like that on it.

evil_lurker - 26-2-2009 at 20:38

Quote:
Originally posted by chemrox
Repair or release from poor Q/C. You could send it to a glassblower and have a 24/40 put on it. If you got it on ebay send it back.


Honestly it ain't worth it when you can buy a brand new one from expediglass for like $40 with shipping included.

$10 to get it there, $10 to get it back, $10 bucks for the joint, and probably $10 for the labor.

pip - 26-2-2009 at 21:50

so I should dispute it and look for a new one? like I said it hasn't been shipped (or paid for) yet

or is it possible the top is clear seal and the bottom is ground glass?

[Edited on 27-2-2009 by pip]

smuv - 27-2-2009 at 05:21

Did you have this picture from the seller before you bid on the item? If this is the case, then you would be a real asshole to dispute it, as it is clear in the picture that there is something off about the joint.

ProChem - 27-2-2009 at 10:06

I have the exact condenser in my lab. the condenser is for reflux only. The top is for a one hole rubber stopper where a calcium chloride tube is fitted. When I use sodium hydride in THF to deprotinate alcohols I use this condenser.

pip - 27-2-2009 at 11:19

I only noticed it after I won it but its cheap enough so i'll buy it. I just wanted to know it was made like that for a reason. also the "asshole" is the person who just called it a 24/40 liebig and never mentioned the other end.

[Edited on 27-2-2009 by pip]