superman (Newbee)
04-15-03 03:54
No 426781
      heating mantle vs. hotplate  Bookmark   

i'm trying to decide whether i should purchase a heating mantle or a hotplate for my first lab.  it will be used primarily for making HI via H3PO4+KI and of course reacting that in a H3PO3 reaction.  both reactions will be done at the 1L size.

from what i've researched the heating mantle is safer, more energy effecient and offers more precise control than the hotplate.  is there anything i'm not factoring into this??    what do the more experienced bee's use?

CODEMAN INC.
 
 
 
 
    gabd
(Hive Bee)
04-15-03 04:29
No 426793
      Depends on the money you want to spend  Bookmark   

After trying both the hotplate and the mantle, I have to say mantles are much better because they offer a finer control over temperature and is much quicker also.
The bad side is that you need different mantles for different flask for optimum performance.

If i was sure only to use a 1L then Id go with the mantle. But you will probably need a stirrer too, which comes with the hotplates most of the time. So its a matter of choice,
I know I like mantles much better
 
 
 
 
    superman
(Newbee)
04-15-03 04:47
No 426799
      i was under the impression that not stirring a  Bookmark   

i was under the impression that not stirring a h3po3 cook at the 1L level wouldn't have much of an impact on yeilds.  if i can get by with the mantle and no stirrer for now,  i would prefer to do so simply because it is a better piece of equipment to use. 

unless the sites i've seen are misleading,  i should be able to get a surplus 1L mantle for under $150can right?   certainly seems worth the money

CODEMAN INC.
 
 
 
 
    Barium
(Hive Addict)
04-15-03 11:14
No 426903
      Yes Yes Yes  Bookmark   

Get yourself a mantle. You cannot compare the efficiency of a mantle with a hotplate. Even better, get a mantle with a intergrated magnetic stirrer.

Freaky
 
 
 
 
    rudebwoy
(Hive Bee)
04-19-03 01:18
No 427932
      hmm  Bookmark   

I think i've seen cheaper 1L heating mantles than 150 us.

I recommend going for a soft jacketed heating mantle and just get a stirrer later on when you make enough cashr0x for a stirrer later on.  
Of course that is if you are going to keep using a 1L heating mantle.

You could always get a 2L heating mantle and fill it with sand for your 1L and use it for future usage.
or 4L but would take some time heating the sand. 

you have to think of the future.  
Invest.

Assess --> Plan --> Perform --> Document
 
 
 
 
    superman
(Newbee)
04-19-03 07:59
No 427989
      mantle  Bookmark   

i appreciate everyone's advice.  i've decided to stick with 1L, no stirring until i'm ready to jump up a few notches or move onto a different project.

i can't wait ;)

CODEMAN INC.
 
 
 
 
    wannaBEE
(Stranger)
06-01-03 13:14
No 436957
      My '03 BigKhem catalog has some thermolyne...  Bookmark   

My '03 BigKhem catalog has some thermolyne heating tape you might wanna look into. ive never used it myself, but im gettin ready to put in an order. it has heating elements dipped in fibrox or silicone with a 482c max temp. you can wrap it around any size flask, use it with a mag stirrer, still see your rxn, and its actually pretty cheap. look around.

anything worth doin...dammit, its worth doin right
 
 
 
 
    yellium
(I'm Yust a Typo)
06-01-03 13:19
No 436959
      No stirring? Are you nuts?  Bookmark   

No stirring? Are you nuts?
 
 
 
 
    superman
(Hive Bee)
06-01-03 17:41
No 436984
      flask heating  Bookmark   

i'll have to look into the tape.  thanks for telling me :)

yellium:   i was under the impression that stirring the h3po3 rxn @ 1L wasn't of significant influence on yeilds,   am i mistaken?

CODEMAN INC.
 
 
 
 
    Rhodium
(Chief Bee)
06-02-03 01:50
No 437074
      always stir while heating  Bookmark   

Yes, stirring is very important, or else the heating of the reaction mixture will be very uneven - very hot near the edges and significantly less towards the center.
 
 
 
 
    mnm
(Hive Bee)
08-11-03 14:20
No 452972
      Hmmm, come to think of it!  Bookmark   

Quote:

My '03 BigKhem catalog has some thermolyne heating tape you might wanna look into. ive never used it myself, but im gettin ready to put in an order. it has heating elements dipped in fibrox or silicone with a 482c max temp. you can wrap it around any size flask, use it with a mag stirrer, still see your rxn, and its actually pretty cheap. look around.

END Quote:


When you mentioned that, kids remembered seeing something similar at the local surplus store. Having owned a mantle or six in the past we recalled the texture was consistant.

Not sure if this is what you are reffering to "thermolyne heating tape" but it'd probably do the trick. This was the smallest size, there were differing lengths and diameters available.



-mnm
 
 
 
 
    RoundBottom
(Hive Addict)
08-12-03 05:19
No 453052
      rubber coated tapes  Bookmark   

also available are the silicon rubber coated variety, good to about 250C, and can be used in a standard mantle controller.  good for wrapping around pyrex carboys for large isomerizations, and performics.  a couple 12' tape can be had cheap on your favorite auction site.



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