What causes stir bars to stop working?

Stir bars seem to have a set lifetime- I have no idea why this would be the case-

What is the mechanism that causes a PTFE Coates magnetic stir bar to just lose responsiveness?

Inb4 @spdking says the word “China”


Temperature basically.


I’m no professional in this subject, in my opinion though I think it’s the Heat after a period of time. I feel like it gets demagnetized after a while.

1 Like

This explains it pretty well. And I know you like to read @Rowan


Well said.

Under 200c but over 150c it’s about 100+ uses.

Over 200c it’s about under 100.

And it’s based on time not runs really. There are better pills. We source a brand with a type that tends to last a bit longer.

Everytime you use the stir bar you use it at a higher temperature, as well as create a demagnetizing field. Basically rotating two polar field against each other to create the physical spin.

I used to use magnets in mechanical modified vaporizers I made. I found that with neodymium magnets I could get about 25,000ish button presses at 4.7v and roughly 80watts. The heat on the magnets was neglible in their positions, i assume it must have been the charged current. Very similar to how a demagnetizing field changes the alignment of atoms.


curie temperature

magnets don’t like heat, you could try samarium cobalt.


Maybe terpenes… Oh wait PTFE… Probably heat then


So is putting weak stir bars in the cryo freezer gonna recharge them?

No. You need to remagnetize it with a charge plate


Fix it…



Science madness is so awesome!!


I find that if I use positive reinforcement my spinbars spin faster for longer at higher temps. I have a nice discussion with the stirbar beforehand, letting the stirbar know my plans and how it is an integral part of process does help. I lose spin almost immediately when I begin yelling at the fucker for not spinning correctly (like I should know how to spin!). My very best magnet that I paid more for really got down an depressed when I yelled at it, but it got mad enough to not work when I threw it against the wall! Little fucker…
Long story short, treat your spinbar well. Have a talk with it, be nice, and be supportive of your spinbars! You have to love them madly, and sometimes furiously… Italics? Am I joking? The world may never know


I second this with just about everything in life. You get out what you put in and if you are putting out a negative attitude most things that result fro tat energy will be negative.

What i found most interesting about magnets is if you talk negatively about one side of the stir bar and positive about the other side it will give you even better results than only being positive.