Sciencemadness Discussion Board

HotPlate Branding

Brightthermite - 13-7-2020 at 18:14

Hey all I am fairly new to purchasing actual chemistry equipment and just purchased the following hotplate.
https://www.amazon.com/Magnetic-Stirrer-100-1600RPM-Control-...

I have seen this exact same hotplate sold from 60-200 dollars. Im looking for tips and brands when purchasing equipment like this. Im sure most of these are all just branded Chinese hotplate. Trying to avoid purchasing expensive equipment that is a knock off.

Deathunter88 - 13-7-2020 at 18:17

Quote: Originally posted by Brightthermite  
Hey all I am fairly new to purchasing actual chemistry equipment and just purchased the following hotplate.
https://www.amazon.com/Magnetic-Stirrer-100-1600RPM-Control-...

I have seen this exact same hotplate sold from 60-200 dollars. Im looking for tips and brands when purchasing equipment like this. Im sure most of these are all just branded Chinese hotplate. Trying to avoid purchasing expensive equipment that is a knock off.


Avoid any Chinese hotplates, that one probably won't even boil a liter of water (160W). Get a reputable one, such as from Corning, Fishersci etc.

Eddie Current - 13-7-2020 at 18:23

Quote: Originally posted by Deathunter88  
Quote: Originally posted by Brightthermite  
Hey all I am fairly new to purchasing actual chemistry equipment and just purchased the following hotplate.
https://www.amazon.com/Magnetic-Stirrer-100-1600RPM-Control-...

I have seen this exact same hotplate sold from 60-200 dollars. Im looking for tips and brands when purchasing equipment like this. Im sure most of these are all just branded Chinese hotplate. Trying to avoid purchasing expensive equipment that is a knock off.


Avoid any Chinese hotplates, that one probably won't even boil a liter of water (160W). Get a reputable one, such as from Corning, Fishersci etc.


Agree. Spend the extra dollars when it comes to HP-stirrers. I paid $250 for a cheap Indian version and it taps out at 160C.........after taking 90 minutes to get there. It costs an extra $100 for one that is rated at 450C that would handle all hobbyist needs.

Syn the Sizer - 13-7-2020 at 19:12

Quote: Originally posted by Deathunter88  

Avoid any Chinese hotplates, that one probably won't even boil a liter of water (160W). Get a reputable one, such as from Corning, Fishersci etc.


I 2nd that, I bought a cheap SH-2 model. It seemed decent until I had to heat something of a decent volume. On top of that even the slightest breeze would cool it down. Lots of wrapping in tinfoil. It lasted decent for the low price but just wasn't adequate. Also the magnetic stir function failed well before the hotplate itself.

G-Coupled - 13-7-2020 at 20:05

Quote: Originally posted by Eddie Current  
Agree. Spend the extra dollars when it comes to HP-stirrers. I paid $250 for a cheap Indian version and it taps out at 160C.........after taking 90 minutes to get there. It costs an extra $100 for one that is rated at 450C that would handle all hobbyist needs.


I think I might know the Indian-made one you mean - are they kind of orange-brown, and is the $100 extra one the higher Indian model (which IIRC was 'digital' and had a decent power rating)?

[Edited on 14-7-2020 by G-Coupled]

Eddie Current - 13-7-2020 at 23:47

Quote: Originally posted by G-Coupled  
Quote: Originally posted by Eddie Current  
Agree. Spend the extra dollars when it comes to HP-stirrers. I paid $250 for a cheap Indian version and it taps out at 160C.........after taking 90 minutes to get there. It costs an extra $100 for one that is rated at 450C that would handle all hobbyist needs.


I think I might know the Indian-made one you mean - are they kind of orange-brown, and is the $100 extra one the higher Indian model (which IIRC was 'digital' and had a decent power rating)?

[Edited on 14-7-2020 by G-Coupled]


No, it isn't one of those, it's a REMI brand and it does have it's uses, but I just should have checked the specs a lot closer. It's useful for temperature sensitive heating with it's slow temperature adjustment.

Brightthermite - 14-7-2020 at 11:08

Quote: Originally posted by Deathunter88  
Quote: Originally posted by Brightthermite  
Hey all I am fairly new to purchasing actual chemistry equipment and just purchased the following hotplate.
https://www.amazon.com/Magnetic-Stirrer-100-1600RPM-Control-...

I have seen this exact same hotplate sold from 60-200 dollars. Im looking for tips and brands when purchasing equipment like this. Im sure most of these are all just branded Chinese hotplate. Trying to avoid purchasing expensive equipment that is a knock off.


Avoid any Chinese hotplates, that one probably won't even boil a liter of water (160W). Get a reputable one, such as from Corning, Fishersci etc.


Im curious now to see if it will boil a liter. Are you purchasing straight from Corning or Fisher, because I see what I assume to be Fisher knock offs all over amazon.

Dr.Bob - 14-7-2020 at 11:28

This is junk. Buy a used Corning or similar one, it will have 4 or 5 times the heating ability and stir better.

Mateo_swe - 14-7-2020 at 12:27

Hotplate/stirrers is one of those items where a used, working good brand one is a better investment than a new low budget one.
The low budget ones work but have low heating power that make heating larger volumes very time consuming.
When you have used a good one you never want one of those cheap, slow units again.
Look at the heating power in watts when you compare different brands and models.

morganbw - 14-7-2020 at 14:44

They really need to have some wattage 600 watts or more a little under is okay but the wattage indicates how much it can heat.

Go with used name brands on the internet stores. I did and it worked out great. I did have to spend more than twice of what you did for a good stirring hotplate.

edit: added a word, deleted another.

[Edited on 7/14/2020 by morganbw]

B(a)P - 14-7-2020 at 15:28

This question seems to come up a lot on this forum and the answer is always the same, 'don't buy cheap/low wattage/unknown brands'. For the record I generally think this is good advice.
However, I think there is something missing and it might be a bit controversial.
I think that cheap low power hotplate stirers do have a place in the home/hobby lab:o.
I own this or very similar. It will boil 1 L of water (on a hot day, wrapped in foil, with no breeze and maybe in direct sun;)). The stirrer is not super powerful and neither is the hotplate, but it has lasted a couple of years with decent use (and abuse). It has withstood some pretty traumatic foam overs (for both me and the hotplate).
Would I use it to distil sulfuric acid, well no, but it is suitable for a great number of things.
You really need to think about what you are going to do. If it is low temperature, smaller volumes then why not go with something cheap and cheerful?
The other thing to consider is maybe a decent heating mantle is where you should invest your money.
Just wanted to put it out there that hotplate stirrers do not have to be able to boil 2 L of sulfuric acid if that is something you never intend to do.

Abromination - 14-7-2020 at 16:53

In terms of choosing a hot plate, it is important to select one with a watt rating of at least 600. This is enough to get well over a hundred degrees c. Those sh 1 models are awful and are hardly able to boil water.

@b(a)p, I had been under the impression that those were garbage.


[Edited on 7-15-20 by Abromination]

B(a)P - 14-7-2020 at 17:17

Quote: Originally posted by Abromination  


@b(a)p, I had been under the impression that those were garbage.


[Edited on 7-15-20 by Abromination]


If you are working on the <250 mL scale and you don't need to go over 150C they are ok. For example I have used mine to go from acetylsalicylic acid to picric acid without issue.
If you want to work in larger volumes and at higher temperatures, yes they are garbage. My point is that they satisfy the needs of what I suspect is a good few hobby chemists.
I would conservatively guess that stirrer has done about 1500 h of work and it is still going strong.
I am not saying it is a good product, just that it does meet certain needs.

Edit - fixed a typo

[Edited on 15-7-2020 by B(a)P]

Mateo_swe - 15-7-2020 at 03:31

There is situations where those cheap hotplate stirrers can very well be used.
If you only do small volume experiments like max 500ml the cheap ones work and there is no reason to buy a hotplate with high heating capacity.
But if you have an hobby interest in chemistry and are going to do many experiments you will find that the 500ml limit will be too small real quick.
So the cheap ones arent useless but they are made for smaller volumes.
And often on ebay they write the hotplate can be used with larger volumes and they can, if you want wait hours before it starts boiling.

If you have some knowledge in electronics and electricity you can buy these heating mantle replacement sleeves on ebay.
They are the resistance heating wire put into glass fibre fabric.
They look like a nitted thing one can have on the head.
These can be driven with a variac or a dimmer circuit and are basicly a heating mantle without enclosure and electrical driver.
These work very good and are very cheap compared to regular heating mantles.
There are outlet voltages involved and one should have some knowledge about voltages and current before trying to connect them to a driver or variac.
Beeing electrocuted doesnt feel nice and can be the last thing you do so be careful if using these sleeves.
There are many videos on youtube about these.

[Edited on 2020-7-15 by Mateo_swe]

XeonTheMGPony - 15-7-2020 at 03:43

As others said never go by temp, go by watts first and foremost and any thing below 500 is going to leave you annoyed and frustrated a lot of the time (your average tea kettle is 1,500w to give you an example)

All ways well worth to save to buy a quality unit, think of it as a near life long tool, you want it to last as you grow to learn its unique quirks you can anticipate it

this really needs to be made into a sticky!

Mateo_swe - 15-7-2020 at 03:57

Someone should do a nice writeup how to make a DIY heating mantle of the replacement inner sleeves.
With a driver circuit and a stirrer function.
I think many would find this very useful.
From these i mean:
https://www.ebay.com/itm/2000ml-500W-Inner-Sleeve-use-for-2-...


2000ml heating mantle inner sleeve.jpg - 37kB

XeonTheMGPony - 15-7-2020 at 05:09

Quote: Originally posted by Mateo_swe  
Someone should do a nice writeup how to make a DIY heating mantle of the replacement inner sleeves.
With a driver circuit and a stirrer function.
I think many would find this very useful.
From these i mean:
https://www.ebay.com/itm/2000ml-500W-Inner-Sleeve-use-for-2-...


I'm making a PID controller for my coffee tin mantles with an immersion probe.

Keftedes89 - 15-7-2020 at 05:46

I don't recommend buying Chinese. Not only will they not heat too high, but they don't last very long because of the more lax manufacturing laws and quality control. I'm all about buying used since the companies price gouge you for new ones.

I personally bought 3 from ebay from the same seller. Decent price and has quite a variety:
https://www.ebay.com/str/jpagora

B.D.E - 19-7-2020 at 21:53

Quote: Originally posted by Deathunter88  
Quote: Originally posted by Brightthermite  
Hey all I am fairly new to purchasing actual chemistry equipment and just purchased the following hotplate.
https://www.amazon.com/Magnetic-Stirrer-100-1600RPM-Control-...

I have seen this exact same hotplate sold from 60-200 dollars. Im looking for tips and brands when purchasing equipment like this. Im sure most of these are all just branded Chinese hotplate. Trying to avoid purchasing expensive equipment that is a knock off.


Avoid any Chinese hotplates, that one probably won't even boil a liter of water (160W). Get a reputable one, such as from Corning, Fishersci etc.

second that. It's actually much much cheaper for the long run.
After buying 3 different Chinese plates that failed at one time or another, I finally decided investing in a used hotplate from Thermo Scientific. It's equvilant to a blind man first seeing colors.

Brightthermite - 20-7-2020 at 11:58

So far the hot plate has worked alright. The plate temp reaches the max temp of 350 C as advertised but can not hold it with any sort of load applied (just doesn't have the power). As others have said this cheap one does work very well for my purposes but if i could go back and spend the extra 70 dollars on one that would work well for ALL purposes I definitely would. I appreciate all the help guys!