Sciencemadness Discussion Board

Cleaning Glas Cols?

monolithic - 2-12-2018 at 15:41

I bought a set of used Glas Col mantles off eBay. They look very clean, other than a slight brown mark where the heating elements lie. The problem is that they stink and burn the fuck out of my eyes/nose whenever I use them. I know I can try to burn them clean at high temperature, but can I try (while unplugged) to wash them off with water? Or would this destroy the heating element?

Dr.Bob - 2-12-2018 at 16:07

Don't overheat them to clean, it will make them worse. The key thing is to regulate the power to them, so that they don;t overheat in the first place. I have used some for 10+ years and they still look great, but I rarely use them above 60 volts, it is almost never needed except for water or DMF, those I mostly heat with an oil bath.

monolithic - 2-12-2018 at 16:40

Quote: Originally posted by Dr.Bob  
Don't overheat them to clean, it will make them worse. The key thing is to regulate the power to them, so that they don;t overheat in the first place. I have used some for 10+ years and they still look great, but I rarely use them above 60 volts, it is almost never needed except for water or DMF, those I mostly heat with an oil bath.


Maybe that's why they stink. This is the first time I used them, to distill water, and I was pushing 90-100V through them.

DavidJR - 2-12-2018 at 17:21

If you really want to clean it, distilled/deionized water is probably okay. Obviously, allow it to dry thoroughly before reuse.

monolithic - 7-12-2018 at 18:16

I ended up scrubbing it with some distilled water and the smell is gone. My next question is: does anyone have a solution (other than an overhead motor) for stirring through a Glas Col? I'm not sure if my PC351's magnet is weak, but it's having trouble stirring at more than 50% speed on something thin like water/ethanol in a 500ml round bottom flask. I doubt it's going to work at all with a solution that's even slightly more viscous.

[Edited on 8-12-2018 by monolithic]

Dr.Bob - 7-12-2018 at 18:28

I would guess that you need a better stir bar, I use a Corning hotplate often and can stir well right through a Glas-Col. But there are limits on how fast they will go, but I can usually get it pretty good.

You need an oval stir bar, big enough to stir well, and curved just slightly more than the flask, so it spins on the center. Many people use too small of a stirbar, that is the main issue I see. Most non-oval stirbars won't work, and cheap Chinese ones may not be very magnetic. The Bel-art oval ones are best.

monolithic - 7-12-2018 at 18:52

Quote: Originally posted by Dr.Bob  
I would guess that you need a better stir bar, I use a Corning hotplate often and can stir well right through a Glas-Col. But there are limits on how fast they will go, but I can usually get it pretty good.

You need an oval stir bar, big enough to stir well, and curved just slightly more than the flask, so it spins on the center. Many people use too small of a stirbar, that is the main issue I see. Most non-oval stirbars won't work, and cheap Chinese ones may not be very magnetic. The Bel-art oval ones are best.

I'm using Chinese stir bars, so that probably is the issue. I guess it's true what they say -- buy cheap, buy twice...

JJay - 8-12-2018 at 00:22

I've used the octagon-shaped Chinese stir bars to stir through a Glas-Col with a Corning hotplate before. It's important to use the right size stirbar and keep the flask well centered. The oval stirbars work better, of course.