Sciencemadness Discussion Board - Bubbles in Pyrex Glassware

Bubbles in Pyrex Glassware

malford - 21-10-2013 at 13:16

I recently purchased for an exceptionally good price a 5000ml Pyrex round bottom flask with three necks.

You can see a picture from the seller:

It has no Pyrex part number and a large bubble in the glass on the bottom. The bubble is roughly 1 mm. I have two questions.

1) are Pyrex components all stamped with part numbers? Could this indicate counterfeit?

2) could the bubble cause any problems with heating?

[Edited on 21-10-2013 by malford]

kristofvagyok - 21-10-2013 at 13:30

Bubbles are usually normal if the glass is repaired, so if it has been broken once and someone "fixed it".

It usually causes no problem, but it's good to test it with something unexpensive: e.g.: boil some water in it and try out that how does it like vacuum while heated.

plante1999 - 21-10-2013 at 13:47

Like if there was a good market for counterfeit pyrex glassware...

[Edited on 22-10-2013 by plante1999]

malford - 21-10-2013 at 15:05

Quote: Originally posted by plante1999

Like if there was a good marked for counterfeit pyrex glassware...

I'm assuming you mean market. If so, I'll also assume you were being sarcastic. If so, I'll also assume you don't know much of economics. If I knew anything about glassblowing, I'd be hiring a couple blowers to produce all kinds of counterfeit Pyrex glassware.

Metacelsus - 21-10-2013 at 15:40

http://www.sciencemadness.org/talk/viewthread.php?tid=22554

Counterfeit Pyrex can be extremely hazardous if used like normal Pyrex.

Blue Matter - 21-10-2013 at 17:06

Malford it doesn't seem like you have very much luck on purchasing glassware between this and the bent vigurex column/condenser. I think that the flask should be fine for boiling non hazardous liquids like stated above I had a beaker with a very small bubble like you did it lasted a while but eventually created a crack.. so be careful

plante1999 - 21-10-2013 at 17:20

I don't believe that's counterfeit pyrex, the chinese beaker was a "pyrox" brand beaker, a copy of pyrex, but not counterfeit, but Malford flask have the right logo disposition and type with the correct brand, I can't see but the country of manufacture should be written on pyrex glass.

@Malford, I know enough in economy to tell you glassware is not the best idea of illegal counterfeit because: The market is mostly limited to hobbyist and researchers, the later buy only from reputable company or directly from the manufacturer, the former is pretty limited in size. If I were to conterfeit something it would not be glass.

PS: Laughing at typo is far from being a gentleman.

Lambda-Eyde - 21-10-2013 at 17:23

Quote: Originally posted by plante1999

@Malford, I know enough in economy to tell you glassware is not the best idea of illegal counterfeit because: The market is mostly limited to hobbyist and researchers, the later buy only from reputable company or directly from the manufacturer, the former is pretty limited in size. If I were to conterfeit something it would not be glass.

PS: Laughing at typo is far from being a gentleman.

My impression wasn't that he was laughing at your typo. With "marked" you could have meant the markings instead of "market", so it was a legit concern.

I think counterfeit Pyrex sounds weird too, but it's also weird that there's no item number or country of origin marked on it. It might be custom made, I don't know if blanks are marked the same way as pre-made glassware. Maybe an e-mail to Corning could shed some light on it?

[Edited on 22-10-2013 by Lambda-Eyde]

elementcollector1 - 21-10-2013 at 17:35

I have a bunch of glassware that isn't marked, and it seems to work quite well.

malford - 21-10-2013 at 19:02

Quote: Originally posted by plante1999

The economics of counterfeiting are that any item which has a retail price supported mostly by its brand often reflected by a simple logo (think Coach bags, Pyrex), is opportune for counterfeiting because logos are easily reproducible.

Lab equipment is not limited to hobbyists and researchers. There are many for-profit small and medium businesses which use lab equipment and would like to keep costs low. In fact, I sold some used lab equipment to a small-to-medium business today.

My post was not meant to ridicule you, it was simply a logical argument based on assumptions. You, in fact, were the one attempting to ridicule me with your sarcasm, but I am not bothered, so have a good day.

---

Blue, I will likely be using it with acids and heat at some point, so your anecdote is disturbing. In that thread about the other crooked glassware I committed to not purchasing from secondary markets anymore but did anyway

malford - 22-10-2013 at 05:23

bfesser - 22-10-2013 at 05:24

I wouldn't worry about it. If you're so concerned, throw it in an annealing oven.

Dr.Bob - 22-10-2013 at 08:37

I have had many flasks with bubbles, both new and repaired, none had any issues with them. And Pyrex mostly marks standard items, many flasks used to be custom made, and thus had no part number. Now there is much more standardization of glassware than when I started. If there was a repair, there should be some other marks, like swirls in the glass, or some faint lines of bubbles where there had been a crack or hole. Nowadays, almost no one repairs glass, as the cost is so high now. But if it was repaired, it would likely have been annealed already, and anyone who repairs glass normally would know to do that. Few people will try to do that without the right equipment and have any luck.

jock88 - 22-10-2013 at 09:19

Be careful if pulling a vacuum on it.

malford - 22-10-2013 at 11:41

Quote: Originally posted by jock88

Be careful if pulling a vacuum on it.

That's exactly what I intend to do!

simba - 22-10-2013 at 17:39

I've had many RBFs with small bubbles within the walls and I never had any problem with them. I've done vacuum distillations at 150ºC for many hours without problems.

chemrox - 23-10-2013 at 14:43

As above, ditto. You could always send it to Corning...