Older stir bar throws easy now

[rtstrider]

Hey all! I have a stir plate and have had the same stir bar for 4 years or so. Recently, say the past 2-4 months, I’ve noticed the stir bar is getting thrown much easier than it used to. Is it possible for a stir bar to lose its “grab” on the magnets over time? I’ve tried two different sets of earth magnets (new and old) just to rule out any weirdness there. Any input would be greatly appreciated!

I’m eyeballing these as replacements for giggles

4 Pcs 30mm(1.18 inch) PTFE Magnetic Stirrer Mixer Stir Bar,White Color,Laboratory Bar,Stir Plate Bar,Stir Plate Magnet,Stir Rod Magnetic Amazon.com

Another option I’ve been eyeballing is a magnetizer for screwdrivers just for giggles. Wanted to see if re-magnetizing the stirbar might help

 

[rtstrider]

Welp found my issue. So this one is a live and learn mistake lol I bought a two pack of earth magnets from the hardware store awhile back. I glued them in place using the opposing poles. Aka the magnets were pushing each other apart instead of pulling together. I’ve had issues with the stir bar being thrown on this new plate (2-4 months old) and well I figured if these are glued in a spot in the same ballpark as the stir bar, in non opposing poles, that would fix it. Low and behold it’s good to go! Maybe someone else can learn from my dumb mistake lol

 

[rtstrider]

And the issue cropped up again this weekend. Ended up purchasing a new stir bar set. The magnetism is much better on this set. I went a tad smaller at 30mm instead of 2 inches. I'm going to go out on a limb and say these stir bars lose magnetism over time. I've been using this one for 4 years or so and it's been HEAVILY used. It's been through 2 cpu fans also. For the price, and mileage, it's had a nice life. These smaller bars will work much better with the stepped starters from the freezer bank going forward. Hoping this helps others! Brew on!

 

[KyBeer]

I built my stir plate and used two small magnets I had. They were about the size of a pencil eraser. They lost some of their strength after three years. I save magnets to keep things like carbonation charts stuck to the side of the fridge where I brew. I have found excellent magnets in old hard drives and electric tooth brush heads. I replaced the magnets with two from tooth bush heads and they work very well.

I recently needed to use my stir plate with a glass carboy. I was adding Glycerin to six gallons of wine and needed to stir for a long time. It was difficult to get the stir bar located and it spun off. I added two very strong magnets to the fan and it worked great. This also helped to de-gas the wine.

I found stronger magnets on the fan made the stir bars stay at higher speeds.

I am looking for a schematic for a variable speed stir plate that uses a 9-12 vdc power cube and a pot for the speed control. I have one somewhere but just can’t remember where.

 

[rtstrider]

I built my stir plate and used two small magnets I had. They were about the size of a pencil eraser. They lost some of their strength after three years. I save magnets to keep things like carbonation charts stuck to the side of the fridge where I brew. I have found excellent magnets in old hard drives and electric tooth brush heads. I replaced the magnets with two from tooth bush heads and they work very well.

I recently needed to use my stir plate with a glass carboy. I was adding Glycerin to six gallons of wine and needed to stir for a long time. It was difficult to get the stir bar located and it spun off. I added two very strong magnets to the fan and it worked great. This also helped to de-gas the wine.

I found stronger magnets on the fan made the stir bars stay at higher speeds.

I am looking for a schematic for a variable speed stir plate that uses a 9-12 vdc power cube and a pot for the speed control. I have one somewhere but just can’t remember where.

Ended up getting new stir bars. Guess the magnetized stir bar wore out after 4 years of very heavy use! New stir bars made a world of difference