Sciencemadness Discussion Board

Chinese Glassware on Ebay vs. Used Pyrex

gdflp - 25-11-2014 at 09:59

I'm thinking of investing in some ground glass glassware, but I'm am trying to decide what to buy. I want the joint size to be 24/40, and the best seller on eBay I've found so far is interlabglassware However, I'm trying to decide if buying glassware from there is the better option, or if it is worth buying used Pyrex. I've already decided that I can't afford new Pyrex since the prices on used Pyrex are already past my budget. Also, does anyone know of a good website which sells used Pyrex? I would order from Dr.Bob but it seems like he's run out of the more common flasks and such. I would appreciate any experiences that anyone would like to share about chinese glass or Pyrex. Thanks in advance!

Mailinmypocket - 25-11-2014 at 10:08

I wish there was an option for both Pyrex and Chinese stuff. Most of the Pyrex/Chemglass/Ace I own is used and performs very well. For Chinese glass I have bought from Laboy glass on ebay (they also have their own site, more items!) and it is very well make and I treat it like Pyrex for the most part with no problems. I have purchased from expediglass and a reducing adapter was poorly made and did not connect snugly to a quality flask like ache glass. This problem never happened with Laboy stuff.

I would take used brand name over Chinese any day as long as it's a deal from a private person such as dr.bob and others.

[Edited on 25-11-2014 by Mailinmypocket]

Zyklon-A - 25-11-2014 at 10:13

I'm happy with new Chinese glass so far. I've only had a few test tubes break from heat shock, and every time it was my fault. (eg. Sucrose potassium chlorate reaction:o in regular glass).
I have bought Pyrex and it's never failed me before, but I haven't had problems with the cheap stuff either.

gdflp - 25-11-2014 at 10:17

Quote: Originally posted by Zyklon-A  
(Sucrose potassium chlorate reaction:o in regular glass).


The same thing happened to me in a pyrex test tube, except the potassium chlorate was molten. Luckily I wasn't the one holding it with a clamp, I convinced my cousin to hold it for me:D

Praxichys - 25-11-2014 at 10:21

I have approximately equal amounts of new Chinese and used Pyrex/Wilmad/Kontes/Ace. I have not had problems with either, although I have noticed that some of the Chinese stuff is thicker at the neck and some keck clips are a bit tight. Performance-wise I have found no difference.

As for acquisition - I just search eBay for the pieces I need and sort by "lowest price + shipping". Sometimes it's new Chinese stuff and sometimes it's used name-brand stuff. Either way, I have only returned one piece of glass in my whole lab career, and that was a brand-new US-made 1L erlenmeyer with a vacuum port with a glass defect.

If you need flasks, I recently picked up a lot of 40 used name-brand RBFs in 24/40. I have 50s, 100s, 250s, and 500s, and I'll let them go for $5 each plus shipping. U2U if interested.

Zyklon-A - 25-11-2014 at 10:23

Yup, that reaction tends to break even pyrex glass, which is why I don't do it in glass anymore (should be a no-brainer). And yeah, it was molten in my case too, I thought that since it was already hot, the shock would be smaller, but of course this caused the reaction to proceed immediately - so the shock was probably greater.

chemrox - 25-11-2014 at 15:59

My vote if for used Pyrex. When you get it wash it and make sure that it comes clean with no beading. My experience with inferior glass is it gets attacked easily.

confused - 26-11-2014 at 07:07

i prefer new chinese glass, mostly because it's cheap and hasn't failed me yet, and also how i have no way of confirming any previous stress on used pyrex glass (I don't own a polarimeter)

dermolotov - 13-12-2014 at 12:29

Quote: Originally posted by confused  
i prefer new chinese glass, mostly because it's cheap and hasn't failed me yet, and also how i have no way of confirming any previous stress on used pyrex glass

x2

Hasn't failed me for vacuum distillations up to 550 torrs. The filter funnels, squibb funnels, etc are a no brainer. They're not being heated so there's no reason to buy $150 pyrex Sep funnels. Proper ventilation, folks!

I also really enjoy ground stoppers from cheap glassware. They're hollow so they don't lock up when you don't use lube (still use it, though). Parrafin oil is perfect for lube there and that's what I use all the time. No more annoying silicon lubricant! :)

with some distillations or refluxes going up to 200deg or higher, I am forced to use a pyrex reaction vessel with my normal Chinese allihn condensor. People tell me of incompatiable glass types but I have not encountered this problem over multiple (250deg) reactions.
Quote: Originally posted by gdflp  
Quote: Originally posted by Zyklon-A  
(Sucrose potassium chlorate reaction:o in regular glass).

The same thing happened to me in a pyrex test tube...


Pyrex test tubes (I believe) are disposable for this reason. :). They are rather thin, too.

[Edited on 13-12-2014 by dermolotov]