Where in Australia I Can Purchase Stir Bars Made with Neodymium Magnets?

[dough]

Hi Brewers,

Anybody know where in Australia I can purchase stir bars made from neodymium magnets? Failing that, import some at reasonable cost.

I figure the stronger the more likely they are to stay spinning in the middle of my unevenly bottomed Erlenmeyer flasks. That spells Neodymium.

It seems the main reason stir bars are made of the magnetically "weaker" Alnico is because when heated that material, retains it's magnetism better compared to Neodymium. Stir plates in labs are, at least sometimes, run hot. Yeast propagation happens at about room temp so why not use stir bars made from neodymium.

I already have a couple of cheap cylindrical stir bars but they:

* are noisy - no central ring/ridge on unevenly bottomed flasks​

* more easily loose their magnetism than my 10 year old neodymium button magnets, despite storing the stir bars "end to end" as mutual "keepers"​

* get thrown occasionally.​

So, perhaps time to try replacing the stir bars.

Neodymium PTFE coated stir bars do exist:
Magnetic Stir Bars - K & J Magnetics - Pennsylvania USA
but the shipping is over $AUD50.

If anyone knows where I can get hold of some suitable neodymium stir bars for reasonable dough please let me know.

Cheers!
Rob

 

[ianh]

I would try a smaller size stirring bar. I dont have any problems with mine and the Erlenmeyer flasks. I use 5 magnetic stirrers for my yeast with 2 and 3 litre flasks.

 

[IanW]

Hi Brewers,

Anybody know where in Australia I can purchase stir bars made from neodymium magnets? Failing that, import some at reasonable cost.

I figure the stronger the more likely they are to stay spinning in the middle of my unevenly bottomed Erlenmeyer flasks. That spells Neodymium.

It seems the main reason stir bars are made of the magnetically "weaker" Alnico is because when heated that material, retains it's magnetism better compared to Neodymium. Stir plates in labs are, at least sometimes, run hot. Yeast propagation happens at about room temp so why not use stir bars made from neodymium.

I already have a couple of cheap cylindrical stir bars but they:

* are noisy - no central ring/ridge on unevenly bottomed flasks​

* more easily loose their magnetism than my 10 year old neodymium button magnets, despite storing the stir bars "end to end" as mutual "keepers"​

* get thrown occasionally.​

So, perhaps time to try replacing the stir bars.

Neodymium PTFE coated stir bars do exist:
Magnetic Stir Bars - K & J Magnetics - Pennsylvania USA
but the shipping is over $AUD50.

If anyone knows where I can get hold of some suitable neodymium stir bars for reasonable dough please let me know.

Cheers!
Rob

I did a search on AliExpress with numerous options as per attached screenshot. Ali postage is usually quite reasonable, cheers, Ian W

 

[dough]

Hi Ianh,
Thanks for replying.

I would try a smaller size stirring bar. I dont have any problems with mine and the Erlenmeyer flasks. I use 5 magnetic stirrers for my yeast with 2 and 3 litre flasks.

Interesting, that's an easy option to try, I'll keep it in mind.

Currently I have two cheap 30mm bars in 5L Erlenmeyer flasks. They were the only size bars available from my general brewing supplier. One rarely gets thrown, the other nearly always gets immediately thrown and both are very noisy. Perhaps a quality local laboratory supplier would be a better option.

If you start digging, it's a bit of a rabbit hole, there are many different shapes and sizes available. According to this selection guide:

How to Choose a Magnetic Stir Bar (Stirring Flea) - stirrers.net

a "slide round", - cylindrical bar with pivot ring around it's middle - or a "Bone" shape may help with non-flat bottoms.

May I ask, which specific stir bars are you using?

Cheers!
Rob

 

[dough]

Hi Ian W,
Thanks for replying to my post.

I did a search on AliExpress with numerous options as per attached screenshot. Ali postage is usually quite reasonable, cheers, Ian W

Thanks for checking AliExpress. Yes the postage it usually very, very reasonable for small items. Actually, it's often cheaper than sending the same parcel to my next door neighbor, which seems unfair for Australian businesses, but perhaps that's a topic for another thread.

I'm looking for PTFE or teflon coated neodymium based stir bars, rather than the "naked" neodymium magnets. I tried searching for them on AliExpress but didn't turn up anything suitable.

Cheers!
Rob

 

[TwoCrows]

Contact either or both of these retailers to confirm your needs.

https://kegland.com.au/products/rep...ZGUzSn2KuMku5y1MxM6-47JyG1DMLWvBcx2EcFLFGzcfM


https://www.kegking.com.au/28mm-pivoting-magnetic-stir-bar.html

 

[dough]

Hi TwoCrows,

Contact either or both of these retailers to confirm your needs.
https://kegland.com.au/products/rep...ZGUzSn2KuMku5y1MxM6-47JyG1DMLWvBcx2EcFLFGzcfM

https://www.kegking.com.au/28mm-pivoting-magnetic-stir-bar.html

Thanks, I'll give them a call after the silly season.
Cheers!
Rob

 

[ianh]

Hi Ianh,
Thanks for replying.

Interesting, that's an easy option to try, I'll keep it in mind.

Currently I have two cheap 30mm bars in 5L Erlenmeyer flasks. They were the only size bars available from my general brewing supplier. One rarely gets thrown, the other nearly always gets immediately thrown and both are very noisy. Perhaps a quality local laboratory supplier would be a better option.

If you start digging, it's a bit of a rabbit hole, there are many different shapes and sizes available. According to this selection guide:

How to Choose a Magnetic Stir Bar (Stirring Flea) - stirrers.net

a "slide round", - cylindrical bar with pivot ring around it's middle - or a "Bone" shape may help with non-flat bottoms.

May I ask, which specific stir bars are you using?

Cheers!
Rob

I have both "slide round" and "pivot ring" and use 25 mm bars, I prefer the "slide round" and I use these magnetic stirrers which I am happy with (I have 5)

https://www.amazon.com.au/Magnetic-...pcontext&ref_=fplfs&psc=1&smid=A35H0SZGNR1N8J

cheers
Ian