Sciencemadness Discussion Board

Fix a Condenser?

elementcollector1 - 30-9-2012 at 19:18

I had a long, borosilicate Liebig condenser, and while I was messing with it, a part of the top connector broke off. It's not ground glass, and I have 2 of the three pieces that broke off. How do I fix this? I would just throw it away, but that seems kind of a waste for something that only had part of the top broken off. I can repair the first two parts back on with the good ol' blowtorch, but what to do about the missing third part?

Nitrator - 30-9-2012 at 20:00

If you have some broken borosilicate glass handy, than you could use a similar sized piece to patch it up. I always keep broken glassware for this reason. You will have to be more careful though when heating or cooling the repaired condenser, as it is much more likely to fracture.

Lambda-Eyde - 30-9-2012 at 20:08

Quote: Originally posted by elementcollector1  
I can repair the first two parts back on with the good ol' blowtorch, but what to do about the missing third part?

No you can't, unless you're skilled in glassblowing and have access to an annealing oven. A piece of glassware is not ready for use until it's been annealed, no exceptions.

Anyways, you're describing your problem too vaguely. It's difficult to answer considering how your question is formulated.

If it's a simple liebig condenser without joints, buying a new one shouldn't set you back much.

Nitrator - 30-9-2012 at 20:15

You certainly can if your skilled enough, but like I said, you have to heat/cool it very gently and reduce as much physical stress as possible. In all likely hood, you will probably fail or it will only last a little while. But it's worth a shot. ;)

Btw, when you buy a new condenser, (you'll have to eventually for sure) don't pay more than 20 bucks for it.

Endimion17 - 1-10-2012 at 02:28

Take a photo and let's have a look.

Dr.Bob - 1-10-2012 at 05:28

If the top is not jointed, just cut the tube shorter, if there is enough tube left, and let it be short. The main thing is to not have a crack left in the glassware, as it will propagate eventually. Same for water inlets and outlets, I have used many condensers with chipped or shortened water tubes, as long as there is enough to wire a tube to, it is OK, although I try to never leave water running for long times unattended in those. Just cut off broken pieces, and fire polish the new edge if you can, or at least sand it with a piece of fine black sand paper.

If you look in most any college organic lab you will see research being done with mostly older glassware, much scratched, chipped, and/or repaired. Minor scratches and small chips are not a big hazard as long as they don't weaken the glassware. However, you should throw out or repair any cracks, with star cracks being easier to repair, larger straight ones rarely are fixable. But broken off tube connectors are common, and if on the outside of the piece, often are fixable.

[Edited on 1-10-2012 by Dr.Bob]

elementcollector1 - 1-10-2012 at 20:24

How does one cut off the top evenly? I don't have a glass inscribing tool.
Photos are coming, camera's busy charging.
So, on the top of the condenser, a huge chip has been taken off the connector, about 2" by 1".
If I cut the afflicted area off, will it still work well as a condenser?

Endimion17 - 2-10-2012 at 01:48

The same way larger glass tubing is cut. After all, the condenser is a bunch of tubes. But it will be easier to tell if someone beside a flameworker could fix it after we see the photos. If the broken part is too close to the condenser's cooling body, I think there's nothing you can do anymore. It would be too complex and would require annealing.

zed - 3-10-2012 at 12:05

The way I remember it, broken glassware ends can be roughly shaped by means of metal "screen door" type screen.

smaerd - 3-10-2012 at 12:49

if only the top joint is broken off it can still be used for reflux.

Glassware repair

cal - 3-10-2012 at 17:52

Quote: Originally posted by smaerd  
if only the top joint is broken off it can still be used for reflux.

I have been using this company for two years now and they have been able to repair everything from a three neck 3000 ml flask to a Graham condenser. Talk to Pam about time frames due to their being busy.Toll Free: 800-899-2137