Sciencemadness Discussion Board

Samduk glassware

Magpie - 4-9-2009 at 20:48

The RBF shown below is presently on ebay for $17-18. I was wondering if anyone has any experience with Samduk's glassware.

http://cgi.ebay.com/NEW-3-neck-Round-bottom-boiling-flask-10...





Samduk RBF.jpg - 22kB

[Edited on 5-9-2009 by Magpie]

Formula409 - 4-9-2009 at 22:14

Not going to make any judgements but that glass looks a tad thin.....
Mind you that is an amazingly cheap price

Formula409.

[Edited on 5-9-2009 by Formula409]

12AX7 - 4-9-2009 at 22:27

Any way to test if it's soda-lime? :D

psychokinetic - 4-9-2009 at 22:30

Quote: Originally posted by Formula409  
Not going to make any judgements but that glass looks a tad thin.....

My thoughts exactly.

kclo4 - 4-9-2009 at 23:57

If it is borosilicate, and you don't plan to be pulling a vac on it, would thin glass really be a problem?

JohnWW - 5-9-2009 at 00:36

A thin glass wall would be a problem, if the flask were to be filled with a heavy liquid, or if violent boiling (which could occur under reduced pressure) were to occur in it. Where is Samduk glassware made? - China? Has anyone had any experience with RBFs of that brand?

Ozone - 5-9-2009 at 05:41

Never heard of it.

Cheers,

O3

watson.fawkes - 5-9-2009 at 06:11

It's a Korean seller: http://samduk-lab.com/ (in Korean), EN translation by Google. It appears there's a Chinese manufacturer behind the scenes, all or in part: http://www.gobizkorea.com/offer/offer_view.jsp?seq=467828&biz_type=1.

stateofhack - 5-9-2009 at 06:54

Bah, they are usually shit! I have a couple of beakers from them and one cracked and one broke, if your not gonna involve heat then its worth it, otherwise not.

watson.fawkes - 5-9-2009 at 11:14

Quote: Originally posted by stateofhack  
Bah, they are usually shit! I have a couple of beakers from them and one cracked and one broke, if your not gonna involve heat then its worth it, otherwise not.
After reading this, I looked closely at the auction photos. There are some unfortunate striations in the necks of the picture flask. Together with your story, I'm guessing their ware may be insufficiently annealed, which is a good way to reduce both manufacturing cost and final quality, particularly in a country (China) where labor is relatively so much less of an input (in money terms) than materials and energy.

There's something else that may be going on. The manufacturer is in a northeast province of China, a little north of Shanghai, and right across the Yellow Sea from South Korea, where the brand holder is. The auction, however, says it's out of Guangzhou, in southern China, next to Hong Kong. It's possible that the auction is dark-grey-market, the seller with a direct line to the manufacturer, perhaps going around the brand holder but using their brand anyway. If this is the case, there may be two grades of glass leaving the factory, one to the brand holder, the other to this seller, but with two different cost bases.

I recently ordered materials for making a polariscope, but they haven't arrived and I won't even get to that project right away they do. Nevertheless, I'd be happy to examine any candidates once I've got the capacity to.

undead_alchemist - 5-9-2009 at 13:24

Quote: Originally posted by watson.fawkes  
Quote: Originally posted by stateofhack  
Bah, they are usually shit! I have a couple of beakers from them and one cracked and one broke, if your not gonna involve heat then its worth it, otherwise not.
After reading this, I looked closely at the auction photos. There are some unfortunate striations in the necks of the picture flask. Together with your story, I'm guessing their ware may be insufficiently annealed, which is a good way to reduce both manufacturing cost and final quality, particularly in a country (China) where labor is relatively so much less of an input (in money terms) than materials and energy.

There's something else that may be going on. The manufacturer is in a northeast province of China, a little north of Shanghai, and right across the Yellow Sea from South Korea, where the brand holder is. The auction, however, says it's out of Guangzhou, in southern China, next to Hong Kong. It's possible that the auction is dark-grey-market, the seller with a direct line to the manufacturer, perhaps going around the brand holder but using their brand anyway. If this is the case, there may be two grades of glass leaving the factory, one to the brand holder, the other to this seller, but with two different cost bases.

I recently ordered materials for making a polariscope, but they haven't arrived and I won't even get to that project right away they do. Nevertheless, I'd be happy to examine any candidates once I've got the capacity to.



The same could be said about Bomex.
Two types were made. One made to ASTM Standards and sold by VEE GEE Scientific, and the stock items made that everyone has had problems with.

stateofhack - 5-9-2009 at 13:36

Meh, why use bomex? I mean its cheaper but a pyrex beaker is better on the long run.

panziandi - 5-9-2009 at 14:23

I always go for Pyrex or Schott. It's worth while putting the extra cash into your hobby, in fact, you can have second hand, and even new, Pyrex and Schott off eBay etc. I wouldn't touch other brands. Saying taht I was given some chinese glass beakers, they are much thinner and I only use them for weighing solids into etc, I would neve buy them!

anotheronebitesthedust - 5-9-2009 at 14:26

I have a 1000ml flat bottom flask by Glassco that I have used in dozens of high temp vacuum distillations as well as reactions and had no problems, I've even dinged it a few times against the sink faucet while cleaning it. It seems very heavy and sturdy.

I also have a UGT 2000ml flat bottom flask that has gone the distance, very heavy and sturdy as well. However I don't like their larger flasks, several of the necks cracked off from the weight of the condensers, but maybe that's a problem that all large flasks with 24/40 necks have. I guess 45/50 would be a wiser choice with larger flasks huh?

And last but not least I gotta say http://www.labdepotinc.com is my favorite supplier. I have not bought flasks from them yet but next time I need one they'll be my first choice, simply because their prices are so reasonable. You just can't beat $50.oo for a 2000ml sep funnel.