I'm interested in buying a stir bar for the first time

[urg8rb8]

Which one should I get? I'm planning to make my own stir plate.

 

[Sadu]

If you look around on Aliexpress you can get a 7 pack of different sized stirbars for 10 bucks, shipping included.

I don't know any better but these work fine for me, and it's nice to have spares in case they get lost.

https://www.aliexpress.com/item/7pc..._6&btsid=ebc246c4-e521-4538-bf71-71fee81bce48

https://www.aliexpress.com/item/7pc..._6&btsid=ebc246c4-e521-4538-bf71-71fee81bce48

 

[urg8rb8]

If you look around on Aliexpress you can get a 7 pack of different sized stirbars for 10 bucks, shipping included.

I don't know any better but these work fine for me, and it's nice to have spares in case they get lost.

https://www.aliexpress.com/item/7pc..._6&btsid=ebc246c4-e521-4538-bf71-71fee81bce48

https://www.aliexpress.com/item/7pc..._6&btsid=ebc246c4-e521-4538-bf71-71fee81bce48

How big is your flask?

 

[urg8rb8]

I also found this:

1 stir bar (the largest from the 7pcs set) for less $2 shipped.

https://www.aliexpress.com/item/10-..._3&btsid=ed09758a-135c-4acc-8e5b-38562202d4d2

 

[Sadu]

Perfect.

Good luck finding one for that price at the HBS.

 

[Sadu]

How big is your flask?

I use a 900ml coffee plunger / french press which has a flat bottom. Can't afford any of that fancy Erlenmeyer flask stuff, as much as I'd like one.

I brew 1 gallon batches so 900ml is plenty big enough.

 

[CU_tony]

6 pack of stir bars of which I found 2 to work adequately in my 2L flask:
https://www.amazon.com/gp/product/B01ASR73B8/?tag=skimlinks_replacement-20

 

[urg8rb8]

Perfect.

Good luck finding one for that price at the HBS.

Yeah forget about it! But its made in China... I'm worried if it has lead or something in it! :fro:

 

[urg8rb8]

6 pack of stir bars of which I found 2 to work adequately in my 2L flask:
https://www.amazon.com/gp/product/B01ASR73B8/?tag=skimlinks_replacement-20

Which two? I think I'm going to buy that single stir bar I pasted above. Then I'll make my own stir plate from extra stuff I have laying around.

 

[CU_tony]

For my setup (link in my signature) the best two were 1" long and 5/8" long. probably the middle two in the six pack I bought.

I bought this six pack because I was unhappy with the stir bar I from the LHBS with a friction ridge that created a rattle. These six were marginally more expensive than the one I had and all six are smooth.
I tested all 6 in water and settled on the two I choose as having the best stir with least amount of noise.

Every setup will be different and having options is a good thing!

 

[skraeling]

I just yank them from work if I need to haha

 

[Jwin]

Note when building you stir plate, gap the magnets where the center of each magnet aligns with the outer end of end of your stir bar. I got a variety pack and set it up to the next to largest stir bar, just incase I was off a little.
Also, make sure the magnets are orbit centrally on you fan.

 

[Hoppy2bmerry]

Smooth rather than the type with a ridge that supposedly helps it spin better... Smooth is quite the other can be very noisy .

 

[urg8rb8]

Note when building you stir plate, gap the magnets where the center of each magnet aligns with the outer end of end of your stir bar. I got a variety pack and set it up to the next to largest stir bar, just incase I was off a little.
Also, make sure the magnets are orbit centrally on you fan.

What do you mean orbit centrally?

 

[urg8rb8]

Smooth rather than the type with a ridge that supposedly helps it spin better... Smooth is quite the other can be very noisy .

I think the type I ordered has the ridge.

 

[Jwin]

What do you mean orbit centrally?

So that the magnets spin in a perfect circle. If they are off centered, it could throw the bar more as it isn't just spinning but also wobbling.
Also, the stronger the magnets, the better. I used neodymium disc magnets, about a 3/8" thick and 1/2" wide. They do well for me.
The biggest struggle with strong magnets is keeping them in place while gluing. I built a shim from scrap wood to place between them while the glue dried. Also. You don't want the magnets directly on the fan as it can be bad to have such a strong magnetic field on the ball bearings. I used a 1/2 PVC cap to mount my magnets on, then glued it to the fan. Fwiw, I used gel super glue with good results since it doesn't run and doesn't instantly bond.
There's plenty of build threads in the day forum with much more advice and part numbers, etc. The adjustable fans on Amazon/eBay are the easiest route, but if you have a fast fan laying around, a $2 PWM controller is a sound investment.

 

[imasickboy]

The ridged bars can rattle, but taking the flask off the plate, and then reseating it can make them silent. You might have to do it a couple of times before it's in the sweet spot. Once it's there, it will stay that way.