Sciencemadness Discussion Board - Any cheap source of magnetic stir bars?

Any cheap source of magnetic stir bars?

Little_Ghost_again - 20-9-2014 at 04:01

Hi
I have over spent! and my overdraft from Bank of dad is now frozen. I finally got a magnetic heated hotplate! It even has a test tube attachment. I have no stir bars though, Ok they are not that expensive but I am after different sizes and they need to be very cheap. any ideas

Mailinmypocket - 20-9-2014 at 04:30

Message SM member Dr.Bob!

Little_Ghost_again - 20-9-2014 at 06:06

Quote: Originally posted by Mailinmypocket

Message SM member Dr.Bob!

Thanks
I already have a chat going on with him over something else, I didnt know he was actually the boards (secret supply source for equipment lol).
I will contact him shortly

careysub - 20-9-2014 at 08:44

I have seen people slip small screws into soda straws and melt them shut with a hot wire or soldering iron.

An inexpensive magnetic stirrer (not hotplate) can be made with a computer case fan and hard drive voice coil magnet. For the magnet take apart a dead or obsolete hard drive, or buy one for a few bucks on eBay. A 9V battery can drive it.

Little_Ghost_again - 24-9-2014 at 07:47

Quote: Originally posted by careysub

I have seen people slip small screws into soda straws and melt them shut with a hot wire or soldering iron.

An inexpensive magnetic stirrer (not hotplate) can be made with a computer case fan and hard drive voice coil magnet. For the magnet take apart a dead or obsolete hard drive, or buy one for a few bucks on eBay. A 9V battery can drive it.

Actually I like the straw idea

, I have heat shrink tubing and some small metal bars! It will do until I can get my order from Dr B

gdflp - 24-9-2014 at 08:01

Another option is China. 5 stir bars for $7USD free shipping

zenosx - 24-9-2014 at 14:22

I have gotten quite a few on amazon for decent pricing. Usually Sigma or similar quality as well. I have everything from flea sized to barely fits through a 24/40 size atm. Just need some tube vanes and I'm set

DrMario - 24-9-2014 at 22:54

Quote: Originally posted by careysub

I have seen people slip small screws into soda straws and melt them shut with a hot wire or soldering iron.

You can make a good quality magnetic stirrer by putting a screw or other magnetic object into a piece of Pasteur pipette, and then weld it shut. Similar to the idea with the straw, except that it will survive higher temperatures and more aggressive chemicals.

CuReUS - 25-9-2014 at 01:17

Quote: Originally posted by Little_Ghost_again

, I have heat shrink tubing and some small metal bars! It will do until I can get my order from Dr B

here is a step by step giude to making your stirplate
http://www.instructables.com/id/How-to-Make-a-Cheap-Portable...

and for the stir bar, i suggest you buy these http://www.permanentmagnet.com/Magnetic_Toy.html

see those two shiny rods with slightly tapered tips(above the caption CREM -MT004 ,they can be used as excellent stir bars ,they even have a thin coating of teflon so your average solvent wont trouble it

Dr.Bob - 25-9-2014 at 06:02

I am running out of the larger sizes of stir bars, but I still have scads of some smaller sizes, including small ovals (1/4 x 1/8"- work well in small rbfs, test tubes, vials, and microwave reactor tubes), small straight ones from 1" down to tiny fleas, and some other odd ones like spin vanes for conical bottom vials, and some other odd ones. The smaller ones are $1 each, or less in bulk.

Little_Ghost_again - 25-9-2014 at 07:17

Quote: Originally posted by Dr.Bob

I am running out of the larger sizes of stir bars, but I still have scads of some smaller sizes, including small ovals (1/4 x 1/8"- work well in small rbfs, test tubes, vials, and microwave reactor tubes), small straight ones from 1" down to tiny fleas, and some other odd ones like spin vanes for conical bottom vials, and some other odd ones. The smaller ones are $1 each, or less in bulk.

I am getting paypal sorted as per our U2U