Stirrer Hotplate

sanking · Mar 6, 2006

I bought a Corning PC-320 hot stirrer hotplate on ebay. It came with no manual and I am trying to figure out how it works. The unit has no on/off power switch, but there are on/off knobs for speed and heat. The adjustments for speed are Slow -2-3-4-5-6, plus On/Off. The adjustments for heat are Low-2-3-4-5-6, plus On/Off. The heat definitley turns on and the platform gets very hot. When I turn on the speed there is a sound, but no visible movement that I can see. Is this normal?

If anyone has one of these units I would appreciate some basic instructions, like to what do the numbers on the knobs correspond in terms of heat and speed.

Sandy

Tammyk · Mar 6, 2006

Hi.

The stirplate has a magnetic piece inside, so you should see stirring if you use a magnetic stir bar inside the liquid you are trying to stir (mostly these are sold as teflon coated shapes to effect different stirring in the form of a vortex). If you put a paper clip on a piece of paper, you should see it turn around, but it should be close to center and start at low speed.

The controls are 0-10 (low to high) for both. On, will start at low I guess.

Tammy

glbeas · Mar 6, 2006

sanking said:
I bought a Corning PC-320 hot stirrer hotplate on ebay. It came with no manual and I am trying to figure out how it works. The unit has no on/off power switch, but there are on/off knobs for speed and heat. The adjustments for speed are Slow -2-3-4-5-6, plus On/Off. The adjustments for heat are Low-2-3-4-5-6, plus On/Off. The heat definitley turns on and the platform gets very hot. When I turn on the speed there is a sound, but no visible movement that I can see. Is this normal?

If anyone has one of these units I would appreciate some basic instructions, like to what do the numbers on the knobs correspond in terms of heat and speed.

Sandy

The knobs are the power switches. You are missing the stirring bar, a magnet encased in plastic. You can find them on Ebay too brand new. Search for your brand online and see if you can determine the size bar you need, I have sizes from a 3/8th inch crossbar to a one inch crossbar and a big three inch bar. You basically need to stich a thermometer in your stock to monitor it, it's just a basic hotplate, no thermostat.

Joe Lipka · Mar 6, 2006

These stirrers use a plastic covered magnet that you put in the glass container that contains your chemicals. The whirring sound is another magnet in the base mounted on a motor. The magnetic attraction causes the plastic covered magnet in the glass container to rotate.

You could probably try looking at a lab supply house for some instructions. Fisher Scientific or Cole Parmer are the two big houses. You could also try the manufacturer, but you probably knew that already.

Photo Engineer · Mar 6, 2006

Sandy, I use the 400 series which has a temperature control probe as well. So, I can leave it unattended and still keep the temperature constant.

PE

pnance · Mar 6, 2006

I have one of these, you might want to clean it outside before you bring it in. You never know what it was used to mix previously. Stuff could have gotten inside as well, it did on mine.

All that aside, you'll never regret getting it, makes mixing developers a breeze.

sanking · Mar 6, 2006

Good advice, but a bit late. I already brought it in and cleaned it.

How do you know if stuff got inside? Did you break it down to find that out or was it obvious for some other reason?

Sandy

pnance said:
I have one of these, you might want to clean it outside before you bring it in. You never know what it was used to mix previously. Stuff could have gotten inside as well, it did on mine.

All that aside, you'll never regret getting it, makes mixing developers a breeze.

DeanC · Mar 6, 2006

I never took mine apart to look inside, just cleaned the top. I picked up an assortment of stirring bars from Lab Safety Supply (best catalog of cool stuff ever) and bought a set of beakers in 25ml-2L sizes from Dead Link Removed.

For temperature control I use one of those kitchen thermometer/timers with the long probe attachment held in the mixing vessel by a soldering stand from Radio Shack (think metal base with two flexible arms that end in alligator clips). I think mine's also a Corning and, if I recall correctly, the highest temperature setting corresponds to something like 900F.

Photo Engineer · Mar 6, 2006

Sandy, I will have my 400 series with me this June. We can go over the details then.

Ok?

PE

df cardwell · Mar 6, 2006

A STIRRING HOT PLATE ???

HOW LONG HAS THAT BEEN GOING ON ????????

d

Papa Tango · Mar 6, 2006

df cardwell said:
A STIRRING HOT PLATE ???

HOW LONG HAS THAT BEEN GOING ON ????????

d

Its a new, secret technology now available only on eBay... Although chemistry labs have had them for over 70 years, they have only recently been declassified. The original technology likely came from a crashed UFO. Be very careful...

grahamp · Mar 6, 2006

I used to use these things in the lab for mixing all sorts of chemicals...

It usually pays to fish out the stirrer before pouring out the solution. Since it is usually magnetic you can often slide it out of a glass beaker with another stirrer. If you are tempted to mix critical solutions in cylinders, don't forget to remove the stirrer before making up the volume. Using containers without a flat base can cause the stirrer to bounce in the magnetic field. That can cause splashing with small volumes.

Otherwise, they are really useful items. I have even seen ones that work using water flow. Not exactly environmentally friendly unless you have a stream outside!

Helen B · Mar 7, 2006

Hi Sandy,

Look here for the Corning manual for a range of hot plate/stirrers. There are tables giving the approximate temperatures and speeds to be expected when setting the dials.

Not all the models of the same type number (eg PC-420) have exactly the same capabilities: the controller boards may have changed, for instance, changing the connectivity to external temperature probes (as mentioned by PE). Early models of the same type may not have the current connections, so be aware of that when buying older gear on eBay etc. The boards are often upgradable, at a price. Corning Life Sciences are very helpful.
Best,
Helen

Jim Noel · Mar 7, 2006

I have a similar magnetic stirrer which I have used for many years.
I do not use glass beakers for stirring because of the danger of breakage. A flat bottomed stainless steel container works as well.
Chemical supply houses sell a long teflon coated rod,the same stuff as on the stirring rods, with an encased magnet on the end. This is used to retrieve the stirring rod prior to pouring the mixture.
Jim

sanking · Mar 7, 2006

Hi Helene,

Thanks for the link. You are obviously much better than me at navigating. I searched the Corning site for twenty minutes this past evening and never found the manuals.

Best,

Sandy

Helen B said:
Hi Sandy,

Look here for the Corning manual for a range of hot plate/stirrers. There are tables giving the approximate temperatures and speeds to be expected when setting the dials.

Not all the models of the same type number (eg PC-420) have exactly the same capabilities: the controller boards may have changed, for instance, changing the connectivity to external temperature probes (as mentioned by PE). Early models of the same type may not have the current connections, so be aware of that when buying older gear on eBay etc. The boards are often upgradable, at a price. Corning Life Sciences are very helpful.
Best,
Helen

pnance · Mar 8, 2006

sanking said:
Good advice, but a bit late. I already brought it in and cleaned it.

How do you know if stuff got inside? Did you break it down to find that out or was it obvious for some other reason?

Sandy

Although originally, I cleaned it completely outside. I kept noticing dust from the inside on the counter around it when I would get it to use. I disassembled it as well as possible. Took the bottom and the top off, thoroughly cleaned the inside. I have no way of knowing what it was dusted with, just wish I have originally done it outside.

Stirrer Hotplate

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