Sciencemadness Discussion Board

Ika or Corning?

SoundClown - 27-12-2020 at 12:38

Hello! Im conflicted with the decision of buying either a corning pc-320 or an IKA RCT- B - S1. Does anybody have experience with both of these manufactures, as Ive only ever owned corning (currently replacing a 351 :/) and would love to get input before dropping $. Also I should mention that I want a hotplate/stirrer that can function under a decent waterbath for say distillation and other purposes in which this feature may be required

EDIT : Pic Upload of Ika

[Edited on 27-12-2020 by SoundClown]

s-l225.png - 68kB

Antigua - 27-12-2020 at 12:44

Both are good, IKA are the best though. Simply built and reliable.

valeg96 - 27-12-2020 at 12:50

The IKA RCT Basic is very slim and the electronics are very close to the heating element, so if you purchase a new one and plan to use it for some serious and frequent heating (for example, daily lab wear), it's going to be dead in 5-7 years. Also, parts are extremely expensive. I suggest you look for some thicker models, such as the C-MAG HS.

SoundClown - 27-12-2020 at 12:52

Quote: Originally posted by Antigua  
Both are good, IKA are the best though. Simply built and reliable.


Thank you! I have similar thoughts

SoundClown - 27-12-2020 at 12:55

Quote: Originally posted by valeg96  
The IKA RCT Basic is very slim and the electronics are very close to the heating element, so if you purchase a new one and plan to use it for some serious and frequent heating (for example, daily lab wear), it's going to be dead in 5-7 years. Also, parts are extremely expensive. I suggest you look for some thicker models, such as the C-MAG HS.


Also thank you! Really good info, I'll look into the C-MAG

Dr.Bob - 27-12-2020 at 14:04

While the IKA is spiffy and great when it works, they break often and are hard to get parts for or repair. But I have 4 or 5 Cornings at work that are all over 10 years old and still working great. I have one IKA which still works, but have had 4 or 5 of them over the last 10-20 years. I have been able to repair 3/4 of the Cornings over the years but only 1/5 of the IKAs. If you are in Europe, they may work better, as that they are designed to work on 220, so the 110 models never do very well, according to the repair people I know.

SoundClown - 27-12-2020 at 14:27

Quote: Originally posted by Dr.Bob  
While the IKA is spiffy and great when it works, they break often and are hard to get parts for or repair. But I have 4 or 5 Cornings at work that are all over 10 years old and still working great. I have one IKA which still works, but have had 4 or 5 of them over the last 10-20 years. I have been able to repair 3/4 of the Cornings over the years but only 1/5 of the IKAs. If you are in Europe, they may work better, as that they are designed to work on 220, so the 110 models never do very well, according to the repair people I know.


How long after purchasing either ika or corning do you find that repairs are needed? also im in US but what do you mean by 220/110? Thanks much in advance!

valeg96 - 28-12-2020 at 01:29

I've somewhat followed up with my institution's technician for the past years when it comes to hotplates. In the last couple years he was given about 8 to 10 IKA RCT basic to repair. All of them were 7 years old or younger, and the nanoprinted PCBs were cooked to fuck (everything else was pretty much intact, but the replacement PCB was around 200€ a piece, so they were simply thrown in the bin). He was also given a dozen of old hotplates (IKA, Heidolph others) from the late 80s-early 00s which were mostly built with simple electronic components and could be repaired with a soldering iron and some new components. If you have the tools and the patience, you could even take an old broken heating element, dig out the resistance from under the aluminium and replace it, then cover it with oven cement. That's the extent to which old stuff can be repaired. I personally have a half dozen hotplates from the 1980s onwards, both classic IKA and heidolph, and they still rock it 30-40 years later.

Digital hotplates, on the other hand, can't be trouble shooted, just thrown away; with an old piece you can always get another one for parts for little money.

Also, old hotplates work with 220V, while new ones work with 24 and 12V circuits, so the stirring isn't as powerful. If you want to buy a new IKA, go for the C-MAG HS, it's a rather sturdy thicc boi.

Also, while the electronics inside the IKA yellow line hotplates are decent and distanced from the heating element, the heating element is a ridiculous filament between two sheets of mica, like a heating pad (you've probably seen NurdRage videos where he keeps trying to repair such burned out filaments). Also, should your hotplate take a hit, the ceramic on yellow line hotplates shatters into a million razor shards, but that's an extreme occurrance.

[Edited on 28-12-2020 by valeg96]

Dr.Bob - 28-12-2020 at 19:34

The IKAs are made for 220 volts, so the wiring is small, as there is X current at 220 V. When you switch them to 110 V, the current is nox 2X, which is right at the limit for the wiring on the boards and components. So they burn out more often when run at 110V due to the larger current freom the mower voltage. Most other hotplates were designed for 110, so they are fine there, and even less current at 220, so they last forever.

teodor - 29-12-2020 at 09:43

Is hotplate stirrer with a water bath is better than just magnetic stirrer + (heating mantle or heat gun) combo? Some liquids have a boiling point more than 80 degrees which requires a bath of something else than water.

valeg96 - 29-12-2020 at 10:18

Baths are always better than mantles or raw hotplate. With liquids that need to be heated to 80-90°C it's good to use a water bath (e.g, distillation of low-boiling solvents such as ethanol, acetone, methanol). To get to temperatures up to 200-250°C you can use a bath with mineral or silicone oil (bought from chemical suppliers) or in some cases even vegetable oil is fine.

Baths provide a more uniform heating surface and reduce the risk of your glassware breaking; if you are distilling acetone over a mantle and it breaks, your lab will go up in flames; if you are using a water bath, it's less likely to.

Just keep in mind that 160°C oil is much, much more hot than boiling water, so you'll need the patience to let it cool down and heat up.

teodor - 29-12-2020 at 11:27

@valeg96 I didn't get much success with water bath + ethanol, the heating is not enough to get a normal distillation speed, but with methanol it works well (results of my experiments with different distillations suggest the external temperature to be in the range 10-30C higher than the boiling point and to get the last drop of a fraction I need exactly +30C).
The problem with oils is that they usually create fumes, so I doubt one can use such a bath without a fume hood.
In case of a mantle and acetone: acetone has autoignition temperature = 465C and a mantle should have almost the same temperature as flask walls (if you have a regulator on it), the same temperature the oil bath will have, or do you think it will be much higher? I don't estimate it as 30-50C higher than a flask, if you use a flask of proper size of course.

I agree that for direct heating (i.e. erlenmeyer) hotplate stirrer is a useful combo. But if the intended usage is a bath/RBF I think you should consider also other alternatives.

Also if I would compare acetone flame burns and hot oil on my knees I don't know what is really better.

[Edited on 29-12-2020 by teodor]

valeg96 - 29-12-2020 at 12:31

Oil does not create fumes, unless you bring it to insane temperatures. If it's silicone oil, or mineral oil, even better (for example, paraffin oil you can find in pharmacies). I've always used oil baths without a fume hood; they don't emit any fume at all. I believe one time a hotplate broke and heated up a silicone oil bath to almost 250°C, and not even then it started fuming; the oil polymerized into a slimy goopy mass.

Mantles have very poor temperature regulation, in my experience; also, hot oil splashes aren't an issue if you work with some common sense (let things cool down before moving them around, for example, and have a labcoat). Anyways, you can do whatever you think works better for you, I'm feeling like a salesman.

teodor - 30-12-2020 at 00:20

@valeg96 I tried only olive oil. It is unpractical to heat it to anything more than 100C in a living room. I have no idea where to buy silicone or paraffin oil, also for reasonable price, but sometimes I have problem with translations. I wouldn't like mineral oil on glassware. I don't like olive oil on glassware either. Also I am very often work with highly oxidising reagents which I don't want to drop into any flammable oil.
I use "ISOPAD Heidelberg" regulator, it is a separate device, I found it very convenient to have a common regulator for different heating devices.
I calibrated it for usage, measuring water temperature inside a flask, so I know which level corresponds to a water bath. I think this calibration is much easier to do for a mantle than for a heating plate because a mantle has thermal insulation, so the temperature inside a flask is not so dependent on the ambient air stream/temperature.
Unlike a bath a mantle doesn't have heat capacity, it cools much faster.

Also I did mention a heatgun. I use Steinel HG2320E, it creates a stream of hot air ("airbath") with temperature 80-650C wich I can regulate with 10C steps. I found it very convenient for distillations (e.g. you can control fractional distillation very precisely) but a bit noisy for long usage like reflux. I can get 98% H2SO4 boiling inside a flask in few minutes with it.


[Edited on 30-12-2020 by teodor]

valeg96 - 30-12-2020 at 01:23

Olive oil has a very low smoke point, and is not good for oil baths. You should go with refined peanut or cornflower oil. The only worse thing you could have chosen is probably butter, or suet

At the hardware store they sell "paraffin oil". You could try with that, it's quite cheap.

teodor - 30-12-2020 at 01:41

Quote: Originally posted by valeg96  
Olive oil has a very low smoke point, and is not good for oil baths.

You see, I tried only this one (what else man could think when they say "oil bath" :) ?) and now I have prejudice against any "oil" in my lab. I hardly can imagine I will spend any EUR for any other oil now, I think it is better to buy a used mantle.
But our differences as well as differences in our labs is interesting point of discussion. It is always amazing to find that other people do things in their home labs completely different.
Quote: Originally posted by valeg96  

At the hardware store they sell "paraffin oil". You could try with that, it's quite cheap.


Is it the same as "kerosene" on my native language? If so I can't imagine how I can use it for a bath - we usually used it as a light source when our power lines were often corrupted in the times of "perestroika". It is very flammable and penetrating. Do you remember that funny story from "3 men in a boat"? (probably you can find this chapter by the title "OBJECTIONS TO PARAFFINE OIL AS AN ATMOSPHERE")

UPD: as you mentioned getting it in pharmacies I think you are talking about something I know by the names "Vaseline" and "Vaseline oil". I never met these substances in hot state except in lamps which are used in our churches. In dutch shops I see "vaseline olie" something like 6EUR per 200ml. Considering the size of bath 3-5L for anything more than 250ml flask I would definitely buy a mantle. Or this

[Edited on 30-12-2020 by teodor]

[Edited on 30-12-2020 by teodor]

valeg96 - 30-12-2020 at 06:10

Kerosene is basically gasoline. Silicone oil or paraffin is not flammable... And can't be used in lamps. I don't use oil baths at home, only at university. I rarely need to heat things that much at home.

I feel it's not as much of a discussion as there is a rather big language barrier. I'm kinda shitting myself at the idea someone could have mistaken my directions on oil baths and set up a kerosene bath.

[Edited on 30-12-2020 by valeg96]

teodor - 30-12-2020 at 09:45

Don't blame yourself, @valeg96, because every novice can read in Vogel's book (as well as in many other books and discussions) something like this:

"Medicinal paraffin may be employed for temperatures up to about 220°. Glycerol
and di-n-butyl phthalate are satisfactory up to 140-150° ; above these
temperatures fuming is usually excessive and the odour of the vapours
is unpleasant. For temperatures up to about 250° " hard hydrogenated "
cotton seed oil, m.p. 40-60°, is recommended : it is clear, not sticky and
solidifies on cooling"

But what exactly is/was a "medical paraffin" is a question. Definitely it is a mixture of alkanes, but what is the lowest C number? I think just enough to have the autoignition temperature higher than your heat source. Probably something close to https://en.wikipedia.org/wiki/Petroleum_jelly with C25 and higher.
Well, when I tried to figure out what to put in my oil bath I found that many things is just to expensive for unsuccessful experiments, so I dropped this idea. The only thing I would invest in probably is Rose Metal. Some people invest in gold, but I think Rose Metal is much better.

[Edited on 30-12-2020 by teodor]

valeg96 - 30-12-2020 at 09:56

There are also metal baths with aluminium beads (or some alloyed metal), but they are very, very expensive (100€/1L). I have never seen them being used in real life; mineral oil is much cheaper.

Medical paraffin is a very refined misture of alkanes, and the composition doesn't matter too much, because it must follow pharmacopoeia regulations on purity and physical properties, so it's the same product everywhere. Ask a pharmacist for a liter of "medical paraffin" and it's the same thing in most countries. And it's cheap. With some good practice, an oil bath lasts hundreds of runs with minimal loss.

unnamed.jpg - 95kB

[Edited on 30-12-2020 by valeg96]

teodor - 30-12-2020 at 11:07

The exact composition still plays some role because I must be sure the lowest boiling point of any hydrocarbon in it is higher than the intended bath temperature. But probably I can distil over everything up to the temperature of the intended usage and then use a mixture of higher fractions. So, you say it doesn't fume and dirty chip. Thanks for the information, it is hard to figure out what exactly to use except ask people with experience. But still I don't see what is wrong with my habbit to use heatgun and mantle with a magnetic stirrer as a separate device.

SoundClown - 30-12-2020 at 11:24

Quote: Originally posted by valeg96  
Olive oil has a very low smoke point, and is not good for oil baths. You should go with refined peanut or cornflower oil. The only worse thing you could have chosen is probably butter, or suet

At the hardware store they sell "paraffin oil". You could try with that, it's quite cheap.


I was actually going to pick up some peanut oil. Do you have experience using peanut oil for higher boiling (140-160c) distillations and if so what comparisons/differences can be identified whilst using other oils such as Parrafin or Sillicone?

valeg96 - 30-12-2020 at 11:27

They are both fine, but I wouldn't use a heating mantle for long, unattended heating, and the heatgun is fine only for quick heating, as the heat source is very focused and not very uniform on the glass. An oil bath can be left unattended for days; it just takes a couple hours to have a stable temperature but then you can just leave it. I believe the longest I ever did it was 5 days at 140°C.

The more refined an oil is, and the less it smells; medical paraffin is so refined you can drink it as a laxative.

My skepticism may be unjustified but I don't trust heating mantles that much...

SoundClown - 30-12-2020 at 11:37

Quote: Originally posted by valeg96  
I've somewhat followed up with my institution's technician for the past years when it comes to hotplates. In the last couple years he was given about 8 to 10 IKA RCT basic to repair. All of them were 7 years old or younger, and the nanoprinted PCBs were cooked to fuck (everything else was pretty much intact, but the replacement PCB was around 200€ a piece, so they were simply thrown in the bin). He was also given a dozen of old hotplates (IKA, Heidolph others) from the late 80s-early 00s which were mostly built with simple electronic components and could be repaired with a soldering iron and some new components. If you have the tools and the patience, you could even take an old broken heating element, dig out the resistance from under the aluminium and replace it, then cover it with oven cement. That's the extent to which old stuff can be repaired. I personally have a half dozen hotplates from the 1980s onwards, both classic IKA and heidolph, and they still rock it 30-40 years later.

Digital hotplates, on the other hand, can't be trouble shooted, just thrown away; with an old piece you can always get another one for parts for little money.

Also, old hotplates work with 220V, while new ones work with 24 and 12V circuits, so the stirring isn't as powerful. If you want to buy a new IKA, go for the C-MAG HS, it's a rather sturdy thicc boi.

Also, while the electronics inside the IKA yellow line hotplates are decent and distanced from the heating element, the heating element is a ridiculous filament between two sheets of mica, like a heating pad (you've probably seen NurdRage videos where he keeps trying to repair such burned out filaments). Also, should your hotplate take a hit, the ceramic on yellow line hotplates shatters into a million razor shards, but that's an extreme occurrance.

[Edited on 28-12-2020 by valeg96]


NurdRage is EXACTLY where I remember seeing that hotplate now that I really think about it lol. Personally I don't like fixing anything that happens to break, so for clarification the general rule of thumb is: the bigger the hotplate - the longer it functions? Also thank you for clarifying the voltage question

SoundClown - 30-12-2020 at 11:39

Quote: Originally posted by valeg96  
Kerosene is basically gasoline. Silicone oil or paraffin is not flammable... And can't be used in lamps. I don't use oil baths at home, only at university. I rarely need to heat things that much at home.

I feel it's not as much of a discussion as there is a rather big language barrier. I'm kinda shitting myself at the idea someone could have mistaken my directions on oil baths and set up a kerosene bath.

[Edited on 30-12-2020 by valeg96]


Lmao what good is a distillation without a sizeable "BOOM" and mushroom cloud of death?

SoundClown - 30-12-2020 at 11:45

Also for those interested, I think I've settled on purchasing a corning pc 420. If anyone has experience with these I would love input, I plan on running peanut oil / water / ice baths with VIGOROUS magnetic stirring. If this plate wont suffice for these operations please let ya boi know

hotplate_corning_pc420_3.jpg - 13kB

[Edited on 30-12-2020 by SoundClown]

teodor - 30-12-2020 at 11:57

@valeg96
This refined oil of alkanes is still flammable and can ignite on some conditions. If you check the information about flash/autoignition temperature of alkanes after C10 you will be surprised that it doesn't go up with increasing number of carbons. And for many of them it is unknown. Various sources say "it can ignite only in gaseous phase". That's why I am personally more comfortable with a mantle. If it would ignite I could at least know what exactly is wrong. I just like to control as many parameters as I can.
Not uniform on the glass ... hm. If I run it several time on the same glassware and everything is OK I can predict it will be OK next time especially if the temperature is lower than the previous time. I always check my glassware with extreme heating before any serious usage. So, I didn't get any evidence that the heating with hot air stream is not so uniform to break something for round bottom and pear shaped flasks made from Duran glass in the range up to 380C. Well, I didn't try vacuum yet. But you are right, it is better to make some shape or compartment which spreads the stream like a real air bath. I very like the idea I saw in this video from Laboratory of Liptakov. But I have no idea which material he used.

[Edited on 30-12-2020 by teodor]

valeg96 - 30-12-2020 at 12:04

Looks like a cheap-ass rip off of an IKA C-MAG HS, I like it. It's probably an IKA hotplate produced by Corning under some kind of license*, with the same pieces and just a cheaper look. It looks like a good choice.

The general rule of thumb is: the slimmer and overly digital it is, the less durable it is, and the more expensive spare parts will be.

*I've seen plenty of those models by different manifacturers, but different looks.

SoundClown - 30-12-2020 at 17:34

Quote: Originally posted by valeg96  
Looks like a cheap-ass rip off of an IKA C-MAG HS, I like it. It's probably an IKA hotplate produced by Corning under some kind of license*, with the same pieces and just a cheaper look. It looks like a good choice.

The general rule of thumb is: the slimmer and overly digital it is, the less durable it is, and the more expensive spare parts will be.

*I've seen plenty of those models by different manifacturers, but different looks.


Excellent! Upon excitedly inquiring for a CMAG HS 7 I noticed that the biggest selling point was its' digital capabilities. However, I possess a digital laser thermometer therefore don't require this feature to be built in especially if it means higher chances of failing in the future. Don't mean to sound cheeky but have u owned a cmag hs for laboratory use? thank you in advance

s-l1600 (1).jpg - 143kB

[Edited on 31-12-2020 by SoundClown]

valeg96 - 31-12-2020 at 01:48

Personally owned, no, but used, yes. Aside from an IKA RCT B, which I never use, everything else I have is 20+ years old. And a design flaw just came to mind, glad you asked that!

Those two knobs on the IKA C MAG are very loose, and do not have a start or intermediate clicks, so they rotate freely. I assume it is to provide a fine temperature control, but... it happened a couple times in our lab that while working near one of them a brush of your hand on the knobs while moving something in was enough to rotate the handles and raise the temperature of the hotplate by 50+ degrees, screwing up the reaction.

It's something very minor, but with that Corning there is zero chance of it happening.

[Edited on 31-12-2020 by valeg96]

SoundClown - 31-12-2020 at 03:01

Quote: Originally posted by valeg96  
Personally owned, no, but used, yes. Aside from an IKA RCT B, which I never use, everything else I have is 20+ years old. And a design flaw just came to mind, glad you asked that!

Those two knobs on the IKA C MAG are very loose, and do not have a start or intermediate clicks, so they rotate freely. I assume it is to provide a fine temperature control, but... it happened a couple times in our lab that while working near one of them a brush of your hand on the knobs while moving something in was enough to rotate the handles and raise the temperature of the hotplate by 50+ degrees, screwing up the reaction.

It's something very minor, but with that Corning there is zero chance of it happening.

[Edited on 31-12-2020 by valeg96]



Thank you for such a detailed response, very grateful for clear comparisons from an individual more experienced than myself