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Rich_Insane
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Hotplates!
Hey guys. So I've decided to get a new hotplate. I'm a bit confused on what I should get. I can't afford those really nice mag stir/lab hotplates, so
I've settled on this: Aroma Hotplate
Is it a good decision? Are there similarly priced options?
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kristofvagyok
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Quote: Originally posted by Rich_Insane  | Hey guys. So I've decided to get a new hotplate. I'm a bit confused on what I should get. I can't afford those really nice mag stir/lab hotplates, so
I've settled on this: Aroma Hotplate
Is it a good decision? Are there similarly priced options? |
It's cheap, it should heat, it is simple, it also has 1 year warranty. Get it and use it.
But a new topic for this?
I have a blog where I post my pictures from my work: http://labphoto.tumblr.com/
-Pictures from chemistry, check it out(:
"You can’t become a chemist and expect to live forever." |
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sargent1015
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eBay!
Personally I'd wait for something to pop up on eBay. I bought my stirrer/hotplate for 40 bucks and it is terrific!
It is a Markinson.
If you want to get that one for now, just to have something, go for it. But, keep your eyes peeled for a really nice one!
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Endimion17
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Have you ever bought really small hotplates like this one?
They're rarely above 500 W, but do their job perfectly. Energy efficient and space saving, they usually cost less than 25$. This one has an 80 mm
diameter plate. It's great for distillations and hotbaths as it doesn't heat up anything else besides the beaker/flask.
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bbartlog
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Neat item, Endimion. I'll have to get one of those at some point. Of course it doesn't have magnetic stirring and probably can't melt zinc, but 75% of
the time it would get the job done.
The less you bet, the more you lose when you win.
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Endimion17
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Given the price of ~22$, it's perfectly fine, although I'd prefer a potentiometer over a 0/I/II button (225 and 450 W) to fine tune the heating.
I doubt it could even melt lead in an insulated iron vessel because its melting point is close to the point where the safety system shuts it down to
prevent overheating damage.
Being so small, it heats up the needed object only. One of the things I really hate is when I have to heat up a small beaker using a large plate. The
rays are killing my fingertips.
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Rich_Insane
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Hey guys, so I have a quick and slightly related question. I'm at maximum budget, and have to cut out the paraffin oil from my purchase. For an oil
bath that needs to reach 120oC, will canola oil be OK? I have several gallons of canola oil, so it would be cheaper for me. Is it a hazard of any
sort?
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sargent1015
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| Quote: Originally posted by Rich_Insane | | Hey guys, so I have a quick and slightly related question. I'm at maximum budget, and have to cut out the paraffin oil from my purchase. For an oil
bath that needs to reach 120oC, will canola oil be OK? I have several gallons of canola oil, so it would be cheaper for me. Is it a hazard of any
sort? |
It'll smell like you are deep frying stuff  So if that's a good smell for you, I
don't see why not
Or you can buy mineral oil (hypoallergenic baby oil)
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Fossil
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Vegetable oil also works decently for oil baths, although if you have some money to spend, get these. http://www.labarmor.com/lab-armor-beads-for-lab-water-baths/
I have some and love them, super convenient, no need for cleaning your glassware of oil, and they go over 500C if i recall correctly. Really a great
investment if you are able to shell out the money.
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reincarn
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For high temp stuff I am thinking of using candle wax.
They are normally paraffin wax (not oil) and I have a box of left-overs.
Bad idea?
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sargent1015
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| Quote: Originally posted by reincarn | For high temp stuff I am thinking of using candle wax.
They are normally paraffin wax (not oil) and I have a box of left-overs.
Bad idea?
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I'm pretty sure that's not a great idea, owing only to the fact that it would be a MESS to clean up. I don't like wax in general..
Plus, mineral oil (paraffin oil) is CHEAP! If you don't want to pick it up at your local pharmacy, check out eBay.
$15: http://www.ebay.com/itm/MINERAL-OIL-1-GALLON-/140489295317?p...
By the way, @Fossil, that bead bath is awesome! I may have to invest in one of them... 
[Edited on 8-5-2012 by sargent1015]
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Funkerman23
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Hey Fossil! they sell to individuals?
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Fossil
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Yes they do, they even give out free samples, to home chemists like us! I highly recommend you check them out as they are very friendly and offer an
extremely good product.
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GreenD
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I have a miniature hot plate / stir plate you can have for 50$.
probably 3x3'' top. Heats up to 250mL easy.
ʃ Ψ*Ψ
Keepin' it real.
Check out my new collaborated site: MNMLimpact.com
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Dr.Bob
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If you use vegetable oil in a heating bath, especially canola oil, it will go rancid before long and smell bad as well as polymerize. Mineral oil,
fully saturated vegetable oil (coconut or palm are OK), and even motor oil are all OK, but many veggie ones will oxidize over time and get nasty.
I haven't tried the beads, although they look great, I may try them out. I use sand, oil and dry Al heating blocks for heating baths.
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Rich_Insane
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| Quote: |
If you use vegetable oil in a heating bath, especially canola oil, it will go rancid before long and smell bad as well as polymerize. Mineral oil,
fully saturated vegetable oil (coconut or palm are OK), and even motor oil are all OK, but many veggie ones will oxidize over time and get nasty.
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Will it go bad after maybe 3-5 hours at 100-150oC? I was thinking of heating some oil for the bath, doing my reaction then dumping the oil (wash the
bath dish afterwards).
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Hexavalent
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I have used saturated vegetable oil previously to heat reactions to at least 200*C. I must have heated and cooled my current batch of oil maybe 10
times, and yet nothing has happened to it. When/if something does happen, its very cheap to replace and I would recommend it for heating baths, based
on my experiences with it.
Personally, I also quite like air and water baths, but I detest sand baths. They are slow to heat, as sand is actually a poor thermal conductor,
messy, and take for ever to get up to the desired temperature and are really slow to cool as well. I have also heard of people putting sand baths in
the oven before placing on the hotplate, to heat them up slightly, but if I can I always try and leave very hot things where they are until they've
cooled.
IIRC, I think a member of this forum once melted the top of their hotplate due to sand baths causing massive thermal insulation.
"Success is going from failure to failure without loss of enthusiasm." Winston Churchill
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sargent1015
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| Quote: Originally posted by Rich_Insane |
Will it go bad after maybe 3-5 hours at 100-150oC? I was thinking of heating some oil for the bath, doing my reaction then dumping the oil (wash the
bath dish afterwards). |
Seems like such a waste.... 
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Hexavalent
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Not really, I would rather replace it than keep rancid oil. You can get veggie oils of all kinds very very cheaply from many wholesalers that sell to
the public . . .failing that, go to the supermarket and get some there. Where I live, I can get 2.5L for just under £3.
"Success is going from failure to failure without loss of enthusiasm." Winston Churchill
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sargent1015
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I agree with after it gets rancid due to multiple use, but for a one time use and dump?
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EssOilChem
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I had a thread on that here, but someone told me that they aren't rated to be that hot. There are some alternatives mentioned in the thread also.
The tech specs on their website confirmed that (-180C - 180C), however real life application may be different I guess.
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grndpndr
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I bought a simple 1100watt single burner by guess and by god temp control HP on sale at the local A+e hdwr for around $15.Its been working fine for a
yr now it just takes care not to overdo heat.Ive seen to many stove fires via cooking oil to feel safe around an oil bath.Ive used sand baths and
they are slow to heat(not to bad with 1100watts) if your simply distilling HNO3.It also worrys me if my glassware should break dumping the contents of
a nitration or distillation(HNO3).Unfounded concerns say with mineral oil?Im also considering copper coated steel BBs?
This may be a stupid idea(not my first) but has anyone tried or considered the use of the cheap unscented clay based kittly litter similar to whats
used to absorb oil spills from garage floors?LOL?
[Edited on 9-5-2012 by grndpndr]
[Edited on 9-5-2012 by grndpndr]
[Edited on 9-5-2012 by grndpndr]
[Edited on 9-5-2012 by grndpndr]
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Rich_Insane
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I think anything with low flammability, low specific heat and low volatility will do... I'm just worried that cooking oil can catch on fire --
although I don't plan on going above 120-150oC.
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Fossil
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| Quote: Originally posted by grndpndr |
I bought a simple 1100watt single burner by guess and by god temp control HP on sale at the local A+e hdwr for around $15.Its been working fine for a
yr now it just takes care not to overdo heat.Ive seen to many stove fires via cooking oil to feel safe around an oil bath.Ive used sand baths and
they are slow to heat(not to bad with 1100watts) if your simply distilling HNO3.It also worrys me if my glassware should break dumping the contents of
a nitration or distillation(HNO3).Unfounded concerns say with mineral oil?Im also considering copper coated steel BBs?
This may be a stupid idea(not my first) but has anyone tried or considered the use of the cheap unscented clay based kittly litter similar to whats
used to absorb oil spills from garage floors?LOL?
[Edited on 9-5-2012 by grndpndr]
[Edited on 9-5-2012 by grndpndr]
[Edited on 9-5-2012 by grndpndr]
[Edited on 9-5-2012 by grndpndr] |
Its is unlikely that the clay would harden the same as if it were in a kiln, but the clay still might harden since it will be heated, therefore the
moisture escaping from it.
[Edited on 2012-5-10 by Fossil]
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grndpndr
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I see your point and the consoderation of the caly hardening slightly due to moisture loss.I would think it would have to contain quite a bit of
moisture but to be sure the 'clay' if prheated to lose the moisture should obviate
that problem.Clever concern tho seems to me,thanks!
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