Sciencemadness Discussion Board - Can somebody recommend a good magnetic stirrer hotplate??

Can somebody recommend a good magnetic stirrer hotplate??

Dynamin - 16-4-2015 at 08:41

Can somebody recommend me a good magnetic stirrer hotplate, please?

I bought this piece of garbage from China on Ebay, and it cant even heat up basic water to a boiling point. It gets stuck around 80 Celsius

http://www.ebay.ca/itm/281432159502?_trksid=p2060353.m2749.l...

My plate needs the following specs:

- Has to be able to heat up to 300 Celsius.
- Has to be able to heat water up to 100 Celsius in under 15 minutes
- Must do at least 1,000 RPM.
- Must be able to handle around 5 lbs of Pyrex bottle weight.
- Must include a portable thermometer.

Thanks in advance

greenlight - 16-4-2015 at 09:24

I have had a bad experience with chinese made heating equipment too, namely a heating mantle.
If you want something really good you will probably have to spend a bit more.
Maybe something from Corning or IKA would be a good choice but quite expensive though so you want to make sure you would use it alot.

I have had an IEC hotplate/stirrer for 4 -5 years now that always works and I have never had a problem with it. It meets all your criteria except for the portable thermometer.
I don't know if you mean a thermometer attached to the hotplate or a digital thermometer temperature reading on the plates controls though.

[Edited on 16-4-2015 by greenlight]

Dynamin - 16-4-2015 at 09:56

Quote: Originally posted by greenlight

I have had an IEC hotplate/stirrer for 4 -5 years now that always works and I have never had a problem with it. It meets all your criteria except for the portable thermometer.
I don't know if you mean a thermometer attached to the hotplate or a digital thermometer temperature reading on the plates controls though

I'll actually take any type of thermometer, so long as its accurate and maintains the liquid at 100 Celsius.

Its very important for the application that I'm doing that the temperature stays precisely at 100 C

[Edited on 16-4-2015 by Dynamin]

[Edited on 16-4-2015 by Dynamin]

greenlight - 16-4-2015 at 18:28

My hotplate has a thermostat which can hold a temperature for a long time as I think just about all of them do.
I just stick a glass lab thermometer in the mixture to be heated and slowly turn the heating dial to bring the heat up to desired temp and wind the dial back slightly when I reach it to keep it there.
Once you do have it sitting at the right temperature, it will stay there for hours.
Some of the IKA hotplates have digital temp reading though if you really do want it, check ebay.

Volanschemia - 16-4-2015 at 19:36

Whereabouts are you Dynamin?
I bought this from an Australian company and it is a fantastic hotplate. It fits all your requirements as well I think.
It comes with an external temp probe that plugs into the device and reads and controls the temperature of the solution directly, which is very handy for precise control of temperature.

jnik - 16-4-2015 at 21:10

Quote: Originally posted by Dynamin

My plate needs the following specs:

- Has to be able to heat up to 300 Celsius.
- Has to be able to heat water up to 100 Celsius in under 15

How much water do you need to heat up? The speed of heating depends on volume. More water you need to boil then more electric power your device needs to consume. But for this one I can't find any info about power.

Another issue related to the way of heating. If you put a liter of water on heating plate in a glass flask without thermal isolation, then you may not achive nesessary temperature, because of high rate of energy dissipation.

Better to keep in mind these technical issues.
Also I can recommend you stirring hotplates by IKA and Daihan. The second one is my faivourite.

Dynamin - 17-4-2015 at 05:55

Quote: Originally posted by TheAustralianScientist

Whereabouts are you Dynamin?
I bought this from an Australian company and it is a fantastic hotplate. It fits all your requirements as well I think.
It comes with an external temp probe that plugs into the device and reads and controls the temperature of the solution directly, which is very handy for precise control of temperature

I'm originally from Amsterdam, Holland. But I now live and work in Toronto.

That little stirrer looks very interesting. Thanx for posting

nora_summers - 17-4-2015 at 08:35

Quote: Originally posted by TheAustralianScientist

Eh? It came with a temperature probe? I ordered it a few weeks ago and I didn't get probe. Did they rip me off?

Dynamin - 17-4-2015 at 12:10

I'm eyeing this one:

http://www.ebay.com/itm/Scilogex-MS7-H550-S-Digital-Square-L...

Volanschemia - 17-4-2015 at 23:31

Quote: Originally posted by nora_summers

Quote: Originally posted by TheAustralianScientist

Eh? It came with a temperature probe? I ordered it a few weeks ago and I didn't get probe. Did they rip me off?

Yeah, mine came without one too and I emailed them. Apparently they forgot and sent me one for free.

NedsHead - 10-6-2015 at 02:54

Is anybody familiar with the Korean made daihan wisestir MSH-20A hotplate stirrer? I spotted one on eBay and impulse got the better of me, paid $250AUD.

Would like to know if they are any good/worth the money

Thanks

gatosgr - 10-6-2015 at 03:12

I'm going to make my own heated stirrer and I was wondering what probe should I buy for temperature measurement?

SunriseSunset - 10-6-2015 at 12:55

Oh my god you paid $200+ on ebay for a hotplate/stirrer that doesn't even reach 100*C?! That seller should accept a return. They even stated in the description that it would reach 300*C.... You could definitely get a refund on it if I were you.. Just hold off on giving him a bad rating if you have not already, and use your rate score as collateral to allow you to return the item. Contact the seller about your return and be sincere! It would probably take a while to ship but it's worth it imo.

In 2010, I got this (The one in the middle) for $90 or less on a bid.

http://www.equipnet.com/lot-of-5-thermolyne-cimarec-1-analog...

It worked great for 5 years. Only thing that happened after a lot of use was the stirrer broke. It would only go from off to full speed, which probably could of been repaired.

But it heated up to 40*C-1000*F no problem and worked perfectly for 5 years. Was an excellent device for the price! I suggest shop ebay over the course of a week or two. Look specifically for sellers that give good details in the description, but also provide decent shipping speed to you. Win yourself a bid and you're likely to stay within a $90 range for your needs!

I just recently baught this: http://www.ebay.com/itm/171797792444?_trksid=p2060353.m2749....

Apparently after it arrived it has a stick on label that says it only goes to 160*C, and it didn't seem like the low heat setting was exactly that low. Stirrer works great however so I'll say it was worth a flat $50.

I think bidding on hotplates for low prices will afford you a better bang for your buck since sellers usually start bids on items they believe are worth bidding for. As for digital temperature reading hot plates, I guess they cost more than 150$ minimum tho.

NedsHead - 10-6-2015 at 17:30

Hi sunrise, it was a bit of a crazy impulse buy but I have been watching eBay for a magnetic stirrer/hotplate for quiet a while and $250 is about the going price here in AUS.

I also looked up the manufacturer website and they claim this hotplate has a max temperature of 380 degrees Celsius, is your statement of "can't even reach 100C" from personal experience or have I missed something?

I haven't received the hotplate so I can't test its capabilities as yet. And yes, the seller will except returns.

SunriseSunset - 11-6-2015 at 09:36

Oh, I thought you said that you received it and found that it couldn't reach 100*C. Never mind, I guess that was my coffee's fault yesterday. There are a lot of distractions where I live. Goood so you might be alright then when you receive it! Cheers

JohnBee - 12-6-2015 at 13:05

I've tried so many hotplates over the years(mostly off eBay) in an effort to keep costs down.
However, it wasn't until I finally bit the bullet and decided to invest in a WVR hotplate that I realized just how much time and money I ended-up wasting.
Long story short, don't skimp on your hot plate stirrer. Unless cleanliness isn't a factor, look for a solidnot painted on enamel) ceramic top and a min. or 750w. After which the motor and magnet size. Though in most cases, ceramic tops and high output devices come with powerful motors/magnets to begin with. Though it doesn't help to do a little spec comparison in the process.

Hope this helps.

PS stay away from Chinese made stirrers as they are all junk *take it from someone who's been there.

NedsHead - 12-6-2015 at 19:07

Thanks for the input JohnBee, the hotplate arrived yesterday and it looks and feels fairly well made.

the model I purchased is 650w and I did a boil test today with some water, a little slow but she got there. I can't test the stirring capabilities until the stirbars I ordered arrive (hopefully Monday)

It has a ceramic top and an overall durable/solid appearance.
So far so good

gatosgr - 12-6-2015 at 22:53

What kind of thermowell (temperature probe casing) do these have, does it reacts with acids e.t.c.?

NedsHead - 13-6-2015 at 03:36

gatosgr, my hotplate doesn't have a thermowell it's a manual/potentiometer type

gatosgr - 13-6-2015 at 06:11

Well I want to build a heater/stirrer with arduino temperature control and need to know what kind of thermowell is needed.

[Edited on 13-6-2015 by gatosgr]