Sciencemadness Discussion Board

Mag stirring through Glas-Col heating mantle?

overunity33 - 19-3-2010 at 15:08

I am trying to price out some equipment. Is it possible to use a hotplate/stirrer to stir through a HARD, aluminium Glas-Col heating mantle or is the distance from the flask to the hotplate too far for the magnets? Anyone have any experience before I order? Thanks.

Fleaker - 19-3-2010 at 15:34

It will stir (at least mine do). Worst comes to worst, get overhead stirring if you're after torque.

bahamuth - 20-3-2010 at 03:34

A little off topic, but have seen a controller of sorts one would fit on the power cord of the mantle and it would create an variable rotating magnetic field within the heating mantle. not sure if this is the way it functions...

Anyone else seen this controller, think it was of Glas-Col make actually. Anyone used this kind of controller?


If it really exists and not another figment of my hopeful imagination..

Vogelzang - 20-3-2010 at 12:21

Aluminum would tend to generate eddy currents. Try a heating mantel without the metal housing.

http://www.google.com/patents?id=mcJXAAAAEBAJ&printsec=d...

[Edited on 20-3-2010 by Vogelzang]

agorot - 20-3-2010 at 12:59

Where are you looking to buy your mantle? The cheapest I've seen are on Ebay. I really think that your hotplate/stirrer is the big x-factor here. It depends largely on how strong your magnet in the stirring component is.

Do you already own your hotplate/stirrer? If you do, my advice is to take your hotplate/stirrer, make the same shape/thickness of your heating mantle that you're looking at out of aluminum foil and fill the insides of that aluminum shell with other bits of aluminum and copper. It may give an indication as to whether your hotplate/stirrer will stir through the real thing.

overunity33 - 20-3-2010 at 20:31

Quote: Originally posted by Vogelzang  
Aluminum would tend to generate eddy currents.
[Edited on 20-3-2010 by Vogelzang]


This wouldn't be a problem as the aluminum would be sitting on a hotplate/stirrer combo anyway. Unless, is there another danger from eddy currents other then generating heat, maybe reducing the magnetic attraction?
Quote: Originally posted by agorot  
my advice is to take your hotplate/stirrer, make the same shape/thickness of your heating mantle that you're looking at out of aluminum foil and fill the insides of that aluminum shell with other bits of aluminum and copper. It may give an indication as to whether your hotplate/stirrer will stir through the real thing.


Thanks, good advice.


Anyone try hooking up a heating mantle to a PID temperature controller+thermocouple? You can set the PID controller and then drop the thermocouple into whatever solution you are trying to heat to get a perfect temperature. The PID based controllers on ebay are around 40$, can hook up to almost any thermocouple and have no problem pushing the power required of a mantle.