Brand new stir bar lost it's magnetism? - Home Brew Forums

Register Now!
Home Brew Forums > Home Brewing Beer > DIY Projects > Chillers & Stir Plates > Brand new stir bar lost it's magnetism?

Reply
 
Thread Tools
Old 11-20-2012, 02:06 AM   #1
bduane
Recipes 
 
Oct 2011
howell, mi
Posts: 202
Liked 13 Times on 10 Posts



Just bought it a few hours ago. I've been playing with my DIY stirplate trying to find the right balance/distance for the magnets on the fan.

When I first started the stir bar would really stick right to where the magnet is and spin no problem at slow speed. But now, the stir bar barely wants to stay over the magnet when it's not moving. Add a little bit of rotation and forget it, it goes off to the side.

When I first bought it, I could easily test polarity by holding an end of the stir bar over the end of my hard drive magnet to see if it attracted or repelled. Now it seems to attract on both ends.

Is it possible that my hard drive rare-earth magnet was strong enough to demagnetize the stir-bar?

 
Reply With Quote
Old 11-20-2012, 02:11 AM   #2
Misplaced_Canuck
HBT_LIFETIMESUPPORTER.png
 
Misplaced_Canuck's Avatar
Recipes 
 
Jan 2011
NE Columbia SC - Formerly, Montreal Canada
Posts: 2,884
Liked 166 Times on 134 Posts


It's a possibility, but doubtful. Are you spinning this in an erlenmeyer, or in a non-flat bottom vessel? Either way, try moving the container left-right, front-back and see if you can get it turning again.

MC
__________________
Quote:
Originally Posted by Misplaced_Canuck
Carbonic bite? Is that like the bubonic plague?
Quote:
Originally Posted by ebstauffer
Needless to say after more than a few drams my mental efficiency matched my mashing efficiency.

 
Reply With Quote
Old 11-20-2012, 02:15 AM   #3
bduane
Recipes 
 
Oct 2011
howell, mi
Posts: 202
Liked 13 Times on 10 Posts


Erlenmeyer...

Shouldn't one end of the stir bar repel from one end of the hard drive magnet?

 
Reply With Quote
Old 11-20-2012, 02:23 AM   #4
bduane
Recipes 
 
Oct 2011
howell, mi
Posts: 202
Liked 13 Times on 10 Posts


I think i did demagnetize it somehow. I read on how to "remagetize" a magnet, basically continuously pass 1 end of a strong magnet over 1 end of the magnet that needs to be magnetized and i did this for a while, and now it seems to repel again at one end.

 
Reply With Quote
Old 11-20-2012, 03:26 AM   #5
dcarter
Recipes 
 
Oct 2006
Posts: 387
Liked 28 Times on 23 Posts


I have never seen a demagnatized stirbar.

 
Reply With Quote
Old 11-20-2012, 03:36 AM   #6
bduane
Recipes 
 
Oct 2011
howell, mi
Posts: 202
Liked 13 Times on 10 Posts


Quote:
Originally Posted by dcarter View Post
Stirbars aren't magnetic they are just an iron bar wrapped in plastic. The magnet is in the stirplate.
A stir bar (or flea) is a magnetic bar used to stir a liquid mixture or solution, usually in a laboratory. The stir bar's motion is driven by a separate rotating magnet or assembly of electromagnets (i.e., coils) located beneath the vessel containing the liquid.

After remagnetizing my stirbar by passing my rare-earth magnet over it repeatedly, it is now working great!


 
Reply With Quote
Old 11-20-2012, 03:56 AM   #7
dcarter
Recipes 
 
Oct 2006
Posts: 387
Liked 28 Times on 23 Posts


Ha! Yeah, I did a quick search and found that my first post was incorrect. Great to see you have your stirbar back to normal!
__________________
Primary:Sierra Nevada Pale Ale Clone

My trash heap fridge rescue and conversion to a first class fermentation chamber

If you don't like your job, you don't strike!.....You just go in everyday and do it really half a$$ed, THATS the American way! - Homer J Simpson

 
Reply With Quote


Reply
Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Stir bar lost in fermenter HoppyMcHopster Equipment/Sanitation 8 05-08-2012 06:37 PM
Lost Abby Lost and Found Dukeman9988 Recipes/Ingredients 3 03-14-2012 06:19 PM
Lost my stir bar..Is there anything else? Rover Fermentation & Yeast 8 08-23-2010 12:16 PM
Brand new kit and brand new brewer... Kesigage Beginners Beer Brewing Forum 11 02-19-2010 09:24 PM
Magnetism and DIY Stirplate jackson_d Chillers & Stir Plates 24 04-24-2009 01:21 AM


Forum Jump