RogueRose - 20-10-2018 at 09:17
I've been looking for a hot plate/stirrer to buy and I have seen these for sale on ebay and they are one of the more "popular" hot plates being sold
at company/University/college surplus auctions. This doesn't necessarily mean they are good but maybe they give good deals to the colleges or
something.
I see a good number of them being sold for "parts only" that look to be in excellent shape and I could buy 2-4 of them for the price of one working
used model.
Either way, has anyone used these or have experience with them?
ScienceHideout - 20-10-2018 at 15:04
I gotta say, I had a Thermolyne Nuova for many years and it served me well until I got a hold of a Fisher Isotemp… then I realized:
Damn, the Thermolynes don't get very hot very quickly!
If you get one (which, they are very inexpensive and very easy to fix, so it is a feasible option) just be prepared to wait 30+ minutes to boil 250 mL
of water. If you have the money, buy something newer.
The research lab I work in has several Nuova emeritus hotplates, and we keep them on 24/7. Their only purpose is to char TLC plates 
weilawei - 20-10-2018 at 18:17
You can get a Corning PC101 with a 10"x10" surface area, heating and stirring, in near mint condition for 100$ if you watch eBay. They're excellent
and highly reliable as well as fast to heat. Put this way: I almost never turn the heating up past 3 (manual gives 3 as max for a sand bath) and it
goes to 7/Hi. 5 will have my pot at a red heat. The stirring is also very good, and I never have to turn that all the way up either
If you're in more of a hurry, they're closer to 200$ shipped, but every so often a cheap but clean one comes up. I have no qualms about paying that
much for a bulletproof piece of gear I use every day, but really good deals do pop up on them.
Whatever you buy, I'd say try to get something without any rust. That's just going to get worse fast. My PC101 is my most used piece of equipment, and
I spend the time to clean it thoroughly after every experiment. You don't want your most frequently used equipment to be rusting through because the
last person didn't care about the equipment.
[Edited on 21-10-2018 by weilawei]
MrHomeScientist - 29-10-2018 at 07:38
I have that Thermolyne hot plate stirrer, and I have no complaints. Works great for everything I've used it for! I think it heats up reasonably
quickly, but I'm also comparing it to a terrible Chinese hot plate that I used to use. For faster heating, I highly recommend getting a hot water
kettle - this is the one I have and I love it. First let the hot plate warm to the desired temperature with your beaker and a little bit of liquid in it.
Then use the kettle to boil the rest of your liquid quickly (it takes just a few minutes), and add that to the beaker on the hot plate. The hot plate
then just has to keep it hot while it boils. If you don't need to boil it, I suppose you could take it off the kettle sooner.
The only problem with my hot plate is that I managed to overheat it while using a sand bath. The white paint on the heating surface is now webbed with
cracks and is flaking off in tiny bits. Didn't affect the heating power though.
Plunkett - 29-10-2018 at 08:42
If you are buying broken hotplates to repair, get them from Dr.Bob. He sent me three broken Corning PC-320s for $25 shipped. All I had to do was wire
a new power cord to get two of them working. The indicator lights on one hotplate flickered but otherwise worked and the second one was flawless.
The third was in rough shape and beyond my ability to repair but I kept it for parts. YMMV. As far as power goes, I left my PC-320 on high once during
a distillation then got distracted and let it distill to dryness. When I came back, the ceramic top was glowing a dull red and parts of the aluminum
foil I was using to insulate the flask had melted. Definitely consider a Corning hotplate/stirrer from Dr.Bob if he has any left.
[Edited on 29-10-2018 by Plunkett]