Sciencemadness Discussion Board

chipped glass

andre178 - 20-1-2010 at 15:23

Hi, I do not yet have to acquire a new rotovap, but the old one got chipped at the end port (ie. where you attach it to the pear shaped evap flask), I was wondering if there is any super glue that will help me attach the chipped piece, which I still have and fits perfectly to the edge of the broken adaptor piece.

Here is a picture of it,

IMG_0074.JPG - 138kB


I suppose the glue should be able to withstand pressure and temperature changes.


Thank you

smuv - 20-1-2010 at 17:17

There is no need to fix it. 2 out of the 4 rotovapps In the lab where I work are chipped in the same place, they work fine. Also, glue's don't hold up well to organic solvents.

If it were not directly on the joint, you could fuse the two pieces together but in this case you will distort the joint.

psychokinetic - 20-1-2010 at 18:40

The only surefire way to fix would be re-blowing, but we don't all have the equipment and skills for that :P

Even then, it may still have problems....but as smuv noted, half the time they still work anyway.

DJF90 - 20-1-2010 at 19:01

Now I'm not entirely sure, but it looks like that cone could be screwed out. Granted you would have to find a replacement but if it's as it looks then it shouldnt be too hard to change. Alternatively, don't worry about it, unless the chip begins to propagate (as a crack perhaps) throughout the cone.

crazyboy - 20-1-2010 at 19:26

Quote: Originally posted by DJF90  
Now I'm not entirely sure, but it looks like that cone could be screwed out. Granted you would have to find a replacement but if it's as it looks then it shouldnt be too hard to change. Alternatively, don't worry about it, unless the chip begins to propagate (as a crack perhaps) throughout the cone.


Those threads are for a combi-clip. You don't really need to worry about it unless it affects its functionality. If it does you might be able to send it to a glass repair specialist.

smuv - 21-1-2010 at 04:45

@psycho* I did not say they work half the time. When they are chipped like that they ALWAYS work. There is nothing wrong with the joint, it is a little shorter but it still works fine.

@DJ590 the cone can be removed, by unscrewing the nut marked "this" in the attached picture. This will expose a glass flange connected to the broken joint. The flange/joint piece may be replaced, BUT IT IS UNNECESSARY. Also note to the OP, the rotovap can be locked from rotation, which facilitates unscrewing the nut, there is usually a button somewhere on the housing of the rotovap to lock it.

@OP If you just got the rotovap used, you may as well take the whole rotovap apart to make sure the bearings are good. When the bearing cease, they strip the drive gears, which is a pain.

[Edited on 1-21-2010 by smuv]

roto.gif - 155kB

psychokinetic - 21-1-2010 at 11:43

Quote: Originally posted by smuv  
@psycho* I did not say they work half the time. When they are chipped like that they ALWAYS work. There is nothing wrong with the joint, it is a little shorter but it still works fine


Right you are. Bad choice of colloquial wording on my part.

andre178 - 21-1-2010 at 12:39

yep you guys were right on all accounts, I can use it like that, I'm just really finnicky with the glassware and found a replacement middle glass tube w/ joint, unscrewed the old one and replaced for now.

And you brought up a good point, the rotovap bearings may be going out, that's the reason why this whole things came into play, it doesn't seal a vaccuum so well anymore.

:(