Magnetic stirring for the unfamiliar

Yeah I was just about to post the same thing haha, it looks really basic and is more than likely so expensive as it is sold to hospitals bur it works great, just tried it through a thick bottom glass and no problem, just need to get myself some assorted glassware now šŸ–’

1 Like

Listed price is $264.00 - $278.00 USD
we poor aliens can only afford to shake :slight_smile:

Iā€™m surprised you can with those skinny grey arms ā€¦:confused:

1 Like

I donā€™t try it with my arms :wink:

3 Likes

Mag Mix or this ā€¦ LOL

Just push down 1000 times

2 Likes

Without rereading this whole thread to find out if this question has been asked @ozo do you happen to know if the magnetic stir bar is one long magnet with a pole at each end or is it a separate magnet at each end of the ptfe bar ?

I have the spinny bit (Fan motor to use the less technical term) to put under the hoojamaflip (box lid) and some magnets for each side of the spinny bit; and want to know if I should have them with the same poles pointing upwards or opposite poles pointing upwards ?

1 Like

Arrange the magnets to have opposite polarities facing up

So Iā€™ve been reading this article, which is very informative by the way, and decided to make a go of it and find a Mag Mix 65904 on fleabay. I found one that looked to be in reasonably good condition and had a good write up, said it worked perfectly and the seller had all good reviews so for $39 bucks I bought it and it arrived super fast. I unbox it, set it up and Iā€™ll tell yaā€¦ That thing was ridden hard and put away wet. It didnā€™t start spinning until 4-5 on the dial and when it did it had a vibration that got worse the faster it went. I pulled the top plate off and found the top bearing totally shot and the shaft is bent, also I noticed that the rheostat was getting extremely hot. I contacted the seller and he promptly refunded my money, he said that it must have gotten damaged in shippingā€¦ Hahaha yeah right.
Now Iā€™m looking for another Stirrer but Iā€™m so hesitant to buy off of fleabay again cause I really donā€™t know anything about these other than what Iā€™ve been reading here and what little research Iā€™ve done. I donā€™t have a lot of money to spend, about 75 bucks and no more. I want to get something decent and I know that new I probably wonā€™t find one so used is probably it, right now Iā€™m lost cause there is a lot of them on there

@Tazz Have a go at making one, I have the bits n bobs coming to make one, Pretty sure that I will get more of a sense of achievement and pride out of the project than buying one PLUS I still get to mix with it too :slight_smile:

Thanks mate :slight_smile:

My home made stirrer from a old computer fan really struggles to spin with a 70/30 mix it just stops it worked fine when I tested with water. think I need a stronger fan as I donā€™t want to heat up my mix, I have a rheostat but not wired up yet as my solder iron went caput but not sure that will help.

My thing is Iā€™m mixing 100-200 ml at a time of all vg minus whatā€™s not for my flavors so Iā€™m looking at about 86% vg, Iā€™d rather buy a good used unit. I have more than enough projects already on my plate to deal with. When I mix I usually donā€™t have a lot of time.

1 Like

I have seen some good ones on ebay, but Have a look at
https://www.hitechtrader.com/Stirrers-Magnetic/3296-sc/mag%20stirrer-Search

1 Like

@Tazz

Per our conversationā€¦

ozo6m
I am familiar with VWR, and the ONLY problem I have about them is they are a bit sketchy with specifications. You should call a representative of VWR and ask for the specs of this particular unit [97042-626]
Last I know this sold retail [medical/pharma industry] for about $350USD new, but donā€™t be fooled by the retail price. I would want to know what RPM this is listed asā€¦0-1000, 0-1500, 0-2000, etc.
That will tell you the level it is rated. This appears to be entry level, like most others , would list as SH-1, SH-2, SH-3 etc
and will tell you about the strength of the magnetā€¦and it should be a single bar magnet, not two separate magnets, and on a continuous use motor.

I will find a link for youā€¦for this, and VWR, when I get a minute.

I donā€™t know this seller either, but these particular pics look good, but I would ask for the particular pics of the exact one he was selling you, since he has two for sale. If this stirrer is this clean, it was not used in a lab using caustics.

ANY mag-stirrer you get, especially used, DO NOT EXPECT it to begin stirring before you turn it almost halfwayā€¦when using VG. You start it after you choose the stir bar for the size beaker, then you adjust the rpm downward.

Lab stirrers are replaced generally after hours of service, and it doesnā€™t mean anything is wrong with them, but magnets lose power over timeā€¦
I have stirrers that cost $1000+ and not even used 250hrs, BUT they are over 10yrs old. They still kick serious ass, but the magnets are not as strong as when they were new.

I still use a 65904 that I bought over 30yrs ago [the one in the thread] and at least 4 days/week, and it saw commercial use most of itā€™s life. I mix 70VG/30PG in 115ml batches, using 250ml low form beakers, because I believe e-juice blends the BEST at that volume. Sometimes up to 400ml batches for bases. You have to learn what stir bar(s) are compatible. One size does not fit all (stir bars), and all beakers are not lab quality with compatible flat bottoms meant for mag-mixing.

For the $$$ and the clean exterior, I would give it a go, but only after the research/questions I posted above. Just because it is clean vs nastyā€¦does not make it better. Depending on the model, I would pay twice the price for a nasty, ugly, funky-looking Barnstead versus a clean pretty little entry level.

One suggestion isā€¦for $25-$35 more, you can find a Biffee SH-2, or similarā€¦and get it new.

I will look for the link now.

https://us.vwr.com/store/product/4644861/vwr-standard-magnetic-stirrers-120v

2 Likes

If you go for a pwm rather than a rheostat you wont need to solder and it regulates the fan better . I have been using 2 in my diy mag mixer for 3 months with no problems

As for the fan i went with a ā€˜ā€˜static pressure fanā€™ā€™ as they have stronger motors

2 Likes

What a great resource this thread is! @ozo What would you recommend as a stirrer for 2L capacities?

I think Ozo took his toys and went home
Sad that it wound up like that
He helped me very much
I wish he would come back even though he sometimes played rough with others just have to learn to take what you need and leave the rest with everyone especially online

2 Likes

What a shame.

2 Likes

So I know this has been discussed here before but I thought id revamp it to get some newer info flowing.

So what sir plate are you guys using heated or unheated price range and how does it handle high vg.

I have an Apera model 601 and the juries still out. I have some small standard magnetic pills and it did a fine job with 15ml of 70/30 pg/vg but when I upped the batch to 60ml it started loosing the pill. Also to further confuse the issue, I was using a vessel with a thick bottom. I have a couple of thinner bottomed vessels on order and also a couple of rare earth pills. Wonā€™t have the pills until end of June. Seems as theyā€™re on back order everywhere.