Author Topic: Heating mantle advice  (Read 3181 times)

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nitrous351

  • Guest
Heating mantle advice
« on: June 30, 2003, 03:46:00 AM »
Ok bees, I need some advice on buying a heating mantle. I know this has been re-hashed on here, but I need advice about a specific model. I am thinking about getting an Electrothermal Electromantle EM1000 CE. I'm tired of using "dangerous" oil baths, and I've been saving for a heating mantle. I found a good deal on the above model, trouble is, I don't know if I can magnetic stir with it. I know the base is made of propylene, so I don't think that would affect the magnet, but I think it has a stainless steel grounding system in it. Does anybee have experience with this particular model? Advice would bee GREATLY appreciated. Any other recommendations?? The hotplate part of my hotplate/stirrer broke and I need a heating source... I am open to ANY advice with heating mantles used with mag. stirring. BTW, I prefer to keep the pricetag under $200 (I prefer used stuff in good working order) THanks all! peace ;D


gabd

  • Guest
Look at this link
« Reply #1 on: June 30, 2003, 04:05:00 AM »
these are the kinds of mantle I use and stirring is no problem. I dont think you need to buy a new one, for the same price you could get 2 or 3 used ones


I dont know about other types of mantle, these are the one I use

nitrous351

  • Guest
yeah, but...
« Reply #2 on: June 30, 2003, 04:14:00 AM »
i know about the soft mantles, but you have to purchase a variac to use them properly. A good used variac is about $50US, plus the cost of the mantle... I was looking at that exact mantle... I emailed the woman 'cause she didn't list the size of it in the auction. She didn't know what size it is, and now I am on her spam Email list. Do you think you can guess what size it is by looking at it? It looks close to 1000mL, but I'm just not sure. I need a 1000ml unit. peace


hCiLdOdUeDn

  • Guest
bee careful...
« Reply #3 on: June 30, 2003, 04:17:00 AM »
No sources.

Please dont tell a public BB where you are getting your lab shit from... its very risky.

nitrous351

  • Guest
sorry
« Reply #4 on: June 30, 2003, 04:27:00 AM »
I was under the impression that that was for chems. I am not talking about purchasing anything illegal or suspicious... I'll do better next time  :)


gabd

  • Guest
Maybe it was a mistake
« Reply #5 on: June 30, 2003, 03:50:00 PM »
putting up that link.
But again it was for a mantle, I didnt know that wasn't allowed either.

unionpacific

  • Guest
Have you thought about finding out whats wrong
« Reply #6 on: July 01, 2003, 04:45:00 AM »
Have you thought about finding out whats wrong with your broken appliance and fixing it? could be a whole lot cheaper than buying a whole new peice , although it does feel good to have new labware

nthingbutareader

  • Guest
VARIACs for mantle control
« Reply #7 on: July 01, 2003, 08:54:00 AM »
You don't really need a VARIAC to control a heating mantle. VARIACs are a big, clunky, ugly, old, and outdated way to do something that the modern technology we have today can do much more efficiently, and I'm surprised at the number of people that still recommend actually using these things... I built a TRIAC "light dimmer" circit for less than $15 in parts, works fine for the purpose, and adds no extra security risks (sparks, etc). They can be built easily with a little some bit of electronics knowledge, or perhaps some research. Or even easier, bought from a hardware store (make sure you get one with a high enough wattage rating), or bought in a kit (only soldering skills required).


http://www.epanorama.net/documents/lights/lightdimmer.html

is an excellent page explaining the operation and lots of details about dimmer circuits, and has some schematics as well. The "Minimal Circuit" will work fine for a heating mantle, and you will notice that typically the other schematics have a capacitor between the "hot" and the "neutral" leads, and an inductor somewhere, which supress "buzzing" when used for dimming an incandescent bulb (explained on this site also), which isn't a problem for a heating mantle anyways.

Also note the wattage ratings on the circits on these sites. The minimal circuit uses a TRIAC/DIAC all-in-one, and the 1000W uses separate TRIAC and DIAC. You can simply replace the TRIAC/DIAC section of the "minimal circuit" for the TRIAC and DIAC in the 1000W circuit, or with any TRIAC/DIAC combination that you can get your hands on.

nitrous351

  • Guest
great advice!
« Reply #8 on: July 01, 2003, 05:56:00 PM »
Reader, thanks chap, good advice! I don't know why I never thought of a dimmer circuit before. It will be fun to build, since I haven't done any electrophysics in a while! Although a person can get a pretty small variac nowadays, they still cost about $50 used...so this will save me at least $30! COOL!


Prince_Charles

  • Guest
Lights dimmer
« Reply #9 on: July 02, 2003, 02:51:00 AM »
A cheap dimmer from my local hardware store (the type you can replace a light switch with) cost a couple of pounds. Rated at 400 W non-inductive load. More powerful ones slightly more. Why build one when they are so cheap?

Surely Americans should be using foot pounds per second to measure power, not the Watt. SI is proscribed under the Patriot Act, I believe.


superman

  • Guest
foot pounds per second...
« Reply #10 on: July 08, 2003, 09:43:00 AM »
foot pounds per second...    can't seem to wrap my head around that.   but being canadian i'm damn glad that americans don't use such a unit


nthingbutareader

  • Guest
foot pounds per second ? SI?
« Reply #11 on: July 09, 2003, 02:41:00 AM »
"pounds" is definately not SI. And according to the first google site on "SI units", the "watt" is a "SI derived" unit.

Maybe you were being sarcastic...

Prince_Charles

  • Guest
Sorry
« Reply #12 on: July 09, 2003, 03:07:00 AM »
I was being sarcastic. It is just that Old Blighty has become very metricated apart from the mile and the pint. One would hope that the Yanks would join us in embracing scientific units. If you send probes to Mars calibrated in units derived from the length Henry VII's penis, what do you expect?