Sciencemadness Discussion Board - Starting my glassware collection: Rare glass joint sizes?

Starting my glassware collection: Rare glass joint sizes?

SaMetal - 13-10-2014 at 05:57

Hello,

I've been lurking on here for a long time and finally decided to start experimenting in real.
After searching a bit, I found a nice website where I can find second hand glassware for cheap.

Because I'm planning to start out with extracting some plants, I was looking for a Soxhlet extractor.
I found a 500ml one for only 20 euros(25 dollar)! I guess that's quite cheap?

However the glass joint sizes are NS29/NS71, while browsing I quickly learned that NS29 is quite common but NS71 is quite rare.
There is a single NS71 Dimroth cooler on sale on the same website 30cm length for 30 euros(38 dollar).

I'm afraid I'll bite my own hand buying stuff with rare joint sizes... Adapters are nowhere to be found second hand and new they cost in the 50 dollar price range, way too expensive.

Can someone suggest me what might be the best choice to do?

DrMario - 13-10-2014 at 06:20

I have no advice to give, but much advice to take - putting a bookmark in this thread, as this is extremely interesting/important info.

Dr.Bob - 13-10-2014 at 06:32

A 29/71 joint should still fit into a 29/42 joint, and visa-versa, which is a little more common, so that may be your best solution. If you still to 14/20 and 24/40, they are very common in the US. In Europe, they might be different length, but will still be the most common, as 24/29 or something like that. There are already several older threads here that discuss the common joint sizes. Just search around the old threads to find them.

careysub - 13-10-2014 at 06:37

I am starting my own glassware collection right now (so I am obviously no expert in lab glass), and since I am interested in chemistry with trace materials and actual chemical experiments (as opposed to extractions or preparations) I opted for the standard 14/20, with adapters that allow me mate with the very common standard 24/40 if I need to go bigger. I am staying away from anything else to avoid having "orphan glass".

There are reasonably priced 24/29 kits out there, but it seems that that is a size developed for student lab kits (smaller, easier to store than 24/40 using smaller amounts of materials) and outside of those kits this joint size is rare.

Soxhlet extractors are a special problem since they need to take that thimble through the top, a super-large joint is required. Perhaps it is best to shop for an extractor-plus-condenser together as a set.

Texium - 13-10-2014 at 07:12

I have pretty much all 24/40, but since I got most of my stuff in a used lot, I also have a bit of 14/20 and 19/38. I'd prefer to have more 14/20 stuff for smaller scale purposes, but since I have a wide variety of 24/40, I work with what I have, but it usually means more mechanical loss and more glass to clean.

Little_Ghost_again - 13-10-2014 at 07:19

I have had trouble getting 29 stuff, much easier in uk to find 34 (or is that 32? cant remember sorry) 24 19 and 14 cheaply.
I have some 29 glassware and getting adapter to fit a 29 flask to a 24 condenser is a joke.
Having said that I normally cheat in this situation and use a rubber bung bored out

Texium - 13-10-2014 at 07:26

Just remembered, I actually have some 34/45 pieces too, but luckily I also have some 34/45 to 24/40 adapters, so they are completely compatible.

SaMetal - 13-10-2014 at 07:48

Thank you all for the info, after searching some more on the forum with different search terms I found this thread:
http://www.sciencemadness.org/talk/viewthread.php?tid=20193

Quote: Originally posted by Endimion17

Actually, the European standard is pretty much the international, world standard. It's the US standard that's somewhat unique, for some weird reason. Therefore, don't buy US glassware as you'll have trouble connecting stuff. These things are quite expensive so mistakes will cost you a lot.
The names of the joints are often shortened, therefore NS24 means NS 24/29, NS29 means NS 29/32, etc.

AFAIK, these are the joints used:
7/16
10/19
12/21
14.5/23 (AKA 14/23 or NS14)
19/26
24/29
29/32
34/35
45/40
60/46
(smaller and larger joints are quite uncommon, though laboratory flameworkers are able to make them if needed)

NS14, NS19, NS24 and NS29 are the most common. Larger ones are usually found on Soxhlet apparatus, and the smaller ones on volumetric flasks.

So since I will need a Soxhlet apparatus anyways and they normally come with the less used larger sized I bought it.
When I'm in need of more than simple extraction I'll go with the more common joints.

Little_Ghost_again - 13-10-2014 at 07:54

24 and 34 are most common in my collections, but I brought joblots on ebay. Latest stuff is 29 and non my condensers fit the flasks!

macckone - 13-10-2014 at 08:18

For a soxhlet extractor you have two fittings.
The bottom one is reasonably standard at 29/32 (or ns29).
The larger one is for the condenser connection and
placing the thimble in the extractor.
NS71 is large for a 500ml extractor and you will
have to find a condenser to fit it. If a thimble
is not included that may be difficult to fit properly.
40/35, 50/40 and 60/45 are more common joint
sizes and should be available for condensers and thimbles.

Dr.Bob - 13-10-2014 at 13:32

I see what you mean, I have never seen a NS71 joint ever, so I thought you were describing the length of the joint with the NS71. People often do that.

Good luck, I would either buy the matching condenser from the guy and treat them gently, or see if you can return the odd ball piece and find a normal jointed set. The normal ones I have had were 34/45 & 24/40 (small), 45/50 & 24/40 (medium) and 55/50 & 24/40 (large). I have even seen one in 19/22, but that was so small as to be silly.

Baffcat - 15-10-2014 at 01:54

Hi

I have two sizes of soxhlet on ebay at the moment. My user name there is the same as here.

I'm not sure if I'm allowed to post this, if not, please remove.

HeYBrO - 15-10-2014 at 01:59

Quote: Originally posted by Baffcat

Hi

I have two sizes of soxhlet on ebay at the moment. My user name there is the same as here.

I'm not sure if I'm allowed to post this, if not, please remove.

You can only post if you give science madness discounts!

Baffcat - 15-10-2014 at 02:09

LOL. Okay, I can do that.

Anyone who quotes these boards to me when buying can have 10% off the listed prices.

Due to ebay's rules, you'd need to pay and then I can refund 10%. Of course, for me it'd be better if you could buy direct, but either way I accept paypal.

I have loads of stuff on there in my ebay shop. Do you think it'd be okay to start a thread mentioning the 10% discount?

Again, if anybody is less than happy about me posting, please delete this.

Cheers

Baffcat

Baffcat - 15-10-2014 at 02:11

Quote: Originally posted by Baffcat

LOL. Okay, I can do that.

Oh, I also know quite a lot about joint sizes, having owned a scientific glassblowing company for 20 years. I'd happily post information about those, or most other glassware.

HeYBrO - 15-10-2014 at 02:35

You don't actually have to do it haha! I would say avoid trying go around ebay rules and maybe just do the transaction through paypal (it will avoid many problems). It shouldn't be a problem to start a threat to introduce your self to the community and tell about yourself and mention the discount. But as i say, it is better not to give the 10% back after, as it could potentially cause issues later.

Dr.Bob - 15-10-2014 at 07:43

Tell us everything you know about joints...

Little_Ghost_again - 15-10-2014 at 11:30

Quote: Originally posted by Baffcat

Hi

I have two sizes of soxhlet on ebay at the moment. My user name there is the same as here.

I'm not sure if I'm allowed to post this, if not, please remove.

Hi
I just wanted to say my dad buys loads of Baffcat (he is ghostman11 Dr Jason Bell or you might know him as the guy that had the same harley as you).

We can very very highly recommend Baffcat as a seller, worst fault so far was shipping too quickly lol

DrMario - 19-10-2014 at 02:49

Since I'm also a beginner with regards to lab glassware, I have a (probably very nooby) question: is 24/29 and 24/40 interoperable? Seeing as though all conical joints have a 10 degree taper, and the first number is the diameter, in mm, of the outer diameter at the base of the cone, I imagine I could fit a 24/40 condenser in a 24/29 Erlenmeyer flask.

Please correct me if I'm wrong.

Texium - 19-10-2014 at 07:20

You're right- they fit together just fine. I have both and use them interchangeably.

macckone - 19-10-2014 at 07:43

24/29 male fittings will always fit 24/40 female fittings.
24/40 male fittings will be long for 24/29 female fittings
which may have interference at the joint weld on the female
fitting. In theory they should fit but it depends on the lack of
interference at the joint weld.

DrMario - 19-10-2014 at 09:12

Thanks zts16 and macckone.