Author Topic: Large stir bars and variable controllers  (Read 2040 times)

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Diggity

  • Guest
Large stir bars and variable controllers
« on: August 15, 2002, 02:20:00 AM »
Swim inquired on the price of a large stir bar for his pet maxi and found the astronomical price of 179.99!!!! WTF! why? Sure, it may be small, and @ 4.25" thats about 50 bux an inch!!! Whatsss goin on guys! What are they doin to us?! 200 bux for a fuckin magnet!!! So frustrated I leave www.tofuckinexpensive and went to another supplier. 249.99 for a 6" bar!!! At this point I ate 2 xanax and smoked 1/2 a cig. Wtf!? Why is this so astronomical for such a small little magnet? Sure it's teflon coated, but since when does teflon cost 249.99! or even 1/100 of that price! 

Anyway, fuck em all, even though they got my money. Bastards.

So now swim decides to compensate for such craziness, he will look for a good deal on a variable transformer for h

is mantle. Can you rig something up at radio shack? Maybe a resistor next to a circuit or sumthin?  ::)

Anyone?

& I'm, somethin of a phenom, 1 puff of da cron, I'm un-stopable.   
 

Psalty

  • Guest
Swim found a 3 1/2" PTFE stir bar for ~$13 and a ...
« Reply #1 on: August 15, 2002, 02:49:00 AM »
Swim found a 3 1/2" Teflon stir bar for ~$13 and a close to 4" Teflon egg shaped stir bar for ~$19.  

The true danger is when liberty is nibbled away, for expedients.  (Edmund Burke)

humidbeing

  • Guest
3 words: Make Them Yourself!!!!!!!
« Reply #2 on: August 15, 2002, 03:52:00 AM »
3 words: Make Them Yourself!!!!!!!
 Easy as hell, and I'll never buy one again.
You were kidding about spending over 20 dollars for one right?
 Right?

  Taking to long to answer.

CG I miss you sweety, I really do.

PrimoPyro

  • Guest
Expensive
« Reply #3 on: August 15, 2002, 04:00:00 AM »
Right now Im looking at a 3/4" x 6" teflon stir bar with ring and it's priced at $66.50 for just one bar. Expensive!

Jesus christ, that is so not worth it.

Scottydog

  • Guest
Magnetic stirrers
« Reply #4 on: August 15, 2002, 04:21:00 AM »
You guys are reading Swis' mind!  :)

Swis had been digging through the search engine a couple months ago and pulled this out of stored info.

Never had any interest in this until now after having read Rhodium's awesome post on another substitute for RP.

Journal of Chemical Education vol 40, December 1963 p 641

This information is supposed to deal with homemade magnetic stirrers. Question is how do I get to this info? I tried typing it verbatim into a search engine...

Flame me if necessary! I just would like to know how to gain access to this information. Please? Thankyou knowledgeable ones...

Edit: A trip to the University library?  :(
____________
Refuse/Resist

foxy2

  • Guest
scotty
« Reply #5 on: August 15, 2002, 04:51:00 AM »
I can get that, will do tomorrow.

Those who give up essential liberties for temporary safety deserve neither liberty nor safety

Diggity

  • Guest
With no vaseline..
« Reply #6 on: August 15, 2002, 08:29:00 AM »
This is an outrage! I never saw any for that price!!!!!

fuck!!! 200 bux for a stir bar!! I feel like naked right now.

<~~~ Got robbbbbbbbed!!! Oh well, Maybe it's a package of 3? Hopefully..

& I'm, somethin of a phenom, 1 puff of da cron, I'm un-stopable.   
 

lugh

  • Guest
Rhodium's Page
« Reply #7 on: August 15, 2002, 10:22:00 AM »
It's already on Rhodium's page  :)  

https://www.thevespiary.org/rhodium/Rhodium/chemistry/equipment/pictures/magstirrer.gif



One tip about this article, for anything larger than a few ml, a nail would need to bee magnetized using a coil; or one could obtain a suitable magnet  ;D

Scottydog

  • Guest
Happy Camper
« Reply #8 on: August 16, 2002, 05:47:00 AM »
Thanks Lugh and everyone for helping Swis to save some cash. Swis also remembers Humid mentioning easy to make stir bars with cylindrical magnets wrapped in teflon.

Post 318295 (missing)

(humidbeing: "homemade stir bars", Chemicals & Equipment)


Now to figure out how to adapt one of these homemade devices to the bottom of a Presxo Cookxr. I wonder if its possible? Swis prefers theoretical oil baths for reflux. Not sure if the electric fryer is made of aluminum. Magnet does not stick to bottom. Only problem Swis contemplates is if the metal is too thick creating a gap reducing the efficiency of the magnet? Speculating again...

Where there's a "Will" there is a hypothetical "Way". Thanks bees!
____________
Refuse/Resist


Flip

  • Guest
Heh
« Reply #9 on: August 16, 2002, 08:07:00 AM »
If you are in need of a six inch stirbar, then I think that the price you would pay in this case would not be prohibitively high, considering the fact that you are in need of a six inch stirbar.

"I like you, but I wouldn't want to see you working with subatomic particles."

Jan1983

  • Guest
whut ??
« Reply #10 on: August 16, 2002, 03:04:00 PM »
try it at ebay ...there swij got such stirrbars for 5- 10€

isnt it worth a try ??

Chemistry are not only the things that stink. :)

Fully_Auto

  • Guest
WTF? Look harder
« Reply #11 on: August 17, 2002, 06:45:00 AM »
108mm x 2  $72 That's 2 stirbars just over 4 inches for $72. $36 a peice

159mm x 2  $108 That's 2 stirbars just over six inches for $108. $54 a peice.

Another source

4.5 inch stirbar $58
6.25 inch stirbar $70

I have a stirbar that's 2.75 inches and it only cost me $7. You need to shop at stores that specialize in the product you need or use smaller companies.

Oh, and the mantle can be controlled with anything that varies a power source. I've seen variable controllers like the ones in the glassware catalogues for $99 at the electronic store.

You could use a router controller found at the hardware. They cost about 15-25 bucks. Just ask for "the switch that controls the speed of the router" They'll know what you're talking about.

I think it was teribum who said you could use a light-dimming switch from the hardware store.