Author Topic: Hotplate/Stirrer  (Read 2731 times)

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CharlieBigpotato

  • Guest
Hotplate/Stirrer
« on: September 17, 2002, 08:58:00 PM »
As we have the "no sources"-policy here,can somebee give me
"general" reccomendations on a hotplat/stirrer?Any special
features to look for?For example,how big would it have to
bee to bee any good,like if one wanted to do the BrightStar
synth?

Rhodium

  • Guest
An IKAMAG® brand hotplate/stirrer is what you ...
« Reply #1 on: September 17, 2002, 09:12:00 PM »
An IKAMAG® brand hotplate/stirrer is what you want.

weedar

  • Guest
Seriously?
« Reply #2 on: September 17, 2002, 09:30:00 PM »
Of course,I had to check out what these were...
Rhodium,can you reccommend anyone of their models?

I like the one with the picture of a cat on it.. ;D
Edit:Ooops,just discovered the animal-pictures weren't
how they were made..Hope somebee finds the page where they
sell those hotplate w/animals though,it was funny.. :)

Weedar

Me fail English?That's unpossible!

Rhodium

  • Guest
Any IKAMAG is good enough for you, what model you ...
« Reply #3 on: September 17, 2002, 10:02:00 PM »
Any IKAMAG is good enough for you, what model you choose is up to your wallet.

pickler

  • Guest
Swim has a 6"x7" hotplate/stirrer that works ...
« Reply #4 on: September 18, 2002, 12:20:00 AM »
Swim has a 6"x7" hotplate/stirrer that works great. No need in getting a thousand dollar hotplate if you can use a one hundred dollar one. Pm me if you need some more details.

I went into the business for the money, and the art grew out of it.-Charlie Chaplin


CharlieBigpotato

  • Guest
Thank you Rhodium!
« Reply #5 on: September 18, 2002, 03:23:00 PM »
That was good advice,I found what I was looking for..

Weedar,I also found that page you found,I think.Very nice
stirrers! ;)

Greets!

scram

  • Guest
Ika is the definately the stirrer with the ...
« Reply #6 on: September 19, 2002, 01:01:00 AM »
Ika is the definately the stirrer with the strongest magnet I've ever seen...Unbelievable. Pay the extra cash to order one of those. I wish I had ripped one off when I had the chance. The only one I've seen that is next to it is the old Cole-Parmer 6x6 stirrers. Don't get Corning. They suck!

algae

  • Guest
digi?
« Reply #7 on: September 20, 2002, 02:45:00 AM »
Would anyone recommend digital readout?  Advantages/disadvantages?

Osmium

  • Guest
Unnecessary. The RCT basic/RET basic work very ...
« Reply #8 on: September 20, 2002, 03:56:00 AM »
Unnecessary.
The RCT basic/RET basic work very well for all your stirring needs.

I'm not fat just horizontally disproportionate.

noj

  • Guest
Corning
« Reply #9 on: September 20, 2002, 06:12:00 AM »
The older Corning hotplates are better than the newer ones they sell. The new ones can't even handle 27.5g Al in MeOH. Which means I have 3 new ones that collect dust and 1 old one that has faithfully served me well for 2 years. The old Corning 351 can handle a 5gal bucket or a MM reduction at 6x scale.

there's a big difference between criticizing your government and criticizing your country

pickler

  • Guest
that's the exact one swim has noj and it does ...
« Reply #10 on: September 20, 2002, 09:19:00 PM »
that's the exact one swim has noj and it does work wonders. Cheap and does the trick.

I went into the business for the money, and the art grew out of it.-Charlie Chaplin


becomezen

  • Guest
call me crazy......
« Reply #11 on: September 27, 2002, 07:30:00 PM »
but why are hotplate/stirrers listed with a temp range of say 60-300°C ...... can this unit not pull a steady 50°C ? Or is it just not verified to be stable outside the listed temp range ?

Slowly , steadily , strongly , becoming zen.

Rhodium

  • Guest
Exactly, not all of them can be turned on at such ...
« Reply #12 on: September 27, 2002, 08:05:00 PM »
Exactly, not all of them can be turned on at such a low energy output. But when do you need to set your hotplate temp to below 60°C?

RoundBottom

  • Guest
also thermolyne 1000
« Reply #13 on: September 27, 2002, 09:00:00 PM »
another combo plate comperable to the older cornings is the thermolyne 1000.  it's major drawback is its height, about twice that of the corning.

Nymphomania is not a disease  - its a goal!  (Methadist on Rosemary Kennedy)

Osmium

  • Guest
> hotplate/stirrers listed with a temp range ...
« Reply #14 on: September 27, 2002, 09:08:00 PM »
> hotplate/stirrers listed with a temp range of say 60-300°C

That is the SURFACE TEMPERATURE of the hot plate! Doesn't mean that you can bring a flask to 300°C!

You can easily set any temp you want, even below 60°C, when you use one of these external switching thermometers and an oil or water bath as a heat sink. I've personally put a 300mm (1 foot) diameter glass crystallising dish with 2 liters of oil and a stir bar in it on top of these stirrers, stuck the temp. probe into the oil, and managed to keep the temp at a steady 40°C. Of course the same can be done with much smaller oil baths, I've done the same with only 100ml oil in an 80mm dish too.
The reason is that the built-in sensor in the heating plate of the stirrer is lagging behind the actual heating taking place by a few seconds due to the mass of the hot plate, so one easily overshoots the desired temperature by a few degrees when no heat sink like a water bath or flask is present. The built-in temp probe and electronics aren't that sensitive either, they can tell the difference between 60°C and 70°C but probably not between 60°C and 62°C.
Just use an oil or water bath in conjunction with a switching thermometer and you can achieve exactly the temperature you want in your oil bath. This of course is only useful when you run reactions at a specific temperature, it's completely irrelevant for distillations!!

I'm not fat just horizontally disproportionate.

nutlin

  • Guest
Corning 351
« Reply #15 on: October 02, 2002, 06:07:00 AM »
I've heard mixed opinions concerning the Corning 351. Someone i talked to said theirs couldnt handle and 27.5g Al in MeOH. But mabe theirs was faulty. Anyone else have any imput on the Corning 351?

handsfull2

  • Guest
yep
« Reply #16 on: October 02, 2002, 06:16:00 AM »
I have a corning 351 combo and it works great .
Paid a dollar for it at a yard sale.......
    8)

  "Go ahead jump  "  


goiterjoe

  • Guest
corning 351
« Reply #17 on: October 03, 2002, 12:47:00 AM »
although not my favorite hotplate/stirrer, I've had one that functioned fine.  the thing would get hot, but the stirrer on it was fairly weak.  On second thought, most reactions I had that involved heavy duty stirring for I would use just a heavy-duty stirrer.

All paths are the same: they lead nowhere

William_Omblome

  • Guest
Heating mantle/stirrer
« Reply #18 on: October 03, 2002, 07:11:00 AM »
I've seen these somewhere but they are really expensive.

wyndowlicker

  • Guest
Hey now!
« Reply #19 on: October 03, 2002, 11:58:00 AM »
Barnstead/Thermolyne

Cimarec stirring hotplate 7X7 Swiw hears they work great! :P

Counting starts by candlelight all are dim ,but one is bright.-GD

RoundBottom

  • Guest
nope
« Reply #20 on: October 03, 2002, 07:56:00 PM »

> Barnstead/Thermolyne Cimarec stirring hotplate 7X7 Swiw hears they work great

from first hand experience, these are one of the weaker stirrers.  they barely can stir anything with a solid in it, let alone Al foil.  they also have a really long spin down time, eg. when your sitr bar flips out, and you turn the stirring down to recapture it, it takes a really long time for the thing to slow down enough to capture the stir bar.

on the other hand, the thermolyne 1000 (big boxy combo) is really strong, and has a quick slow down rate.  and they're cheap like, well, like something that doesn't cost too much.

Nymphomania is not a disease  - its a goal!  (Methadist on Rosemary Kennedy)

wyndowlicker

  • Guest
Hmmm!
« Reply #21 on: October 04, 2002, 01:13:00 AM »
Swiw had heard that spinnout happens every now and again the AL/hg+nitro via 25ml stufferol.It does cause a little paranoia.You do wanna check on it every 10 minutes.Anyone know of a good digi term HP stirrer model?When adding NaCL to elenmeyer to hook up some brine solution swiw gets spinnout.That slow down rate can piss ya off quick.  :P

Counting starts by candlelight all are dim ,but one is bright.-GD

scram

  • Guest
I think thermolynes suck too.
« Reply #22 on: October 05, 2002, 06:12:00 PM »
I think thermolynes suck too. There really aren't that many strong stirrer out there unless you go with Ika or PMC.

pHarmacist

  • Guest
If the magnet stirring isn't sufficiant, use ...
« Reply #23 on: October 05, 2002, 06:13:00 PM »
If the magnet stirring isn't sufficiant, use overhead stirring.. case closed...

[pH]armacist - Snälla, inga fler privata meddelanden från wanabees (magiskamolekyler.org)

RoundBottom

  • Guest
i think you mean thermolyne cimarecs.
« Reply #24 on: October 05, 2002, 08:38:00 PM »
i think you mean thermolyne cimarecs.  thermolyne 1000s are very strong, stop quickly, and are dirt cheap.

Nymphomania is not a disease  - its a goal!  (Methadist on Rosemary Kennedy)

Diggity

  • Guest
Enough is enough! Spend the fuckin money already!
« Reply #25 on: October 06, 2002, 10:15:00 AM »
Heres the deal.. seriously. If your novice and refuse to use sheet al for WHATEVER REASON, then get a 12L, 2 neck rb, and a thermoleyne maxi stirrer for overkill. Then insert your 45/50 (400mm) friedrick into the top of your 12L and your 24/40 addition funnel into your side neck.. 3" stir bar inside the place to bee and scale up MM's synth 8/9 X

This will work and I guarantee you will not feel any heat on the top part of the condensor as ice cold water flows through it. Give the addition 2/3 hours and you will be stuck with more liquid than you really want. Get a 20L carboy with spigot to seperate or something. At that point you figure you just spent 2 grand on equipment and just made 10K back on your first unnecessary large scale rxn. - the cost of sodium hydroxide to basify. That will be pricey.

Ghetto as fuck, but whatever, you only live once and seeing even half of this scale being done is enough to catch a natural high.

After you do this once.. make it a point to never do it again. Pay OS his AL/HG money and use sheet metal from that point on.   ;)

Oh yea.. He DOESNT accept american express.. but will gladly take food stamps.  :P  He likes food.  :P  ;D  :P  ;D  :P

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