Sciencemadness Discussion Board - Why are 10/30 thermometers as rare as hen's teeth, but 10/30 joints a dime a dozen?

Why are 10/30 thermometers as rare as hen's teeth, but 10/30 joints a dime a dozen?

GammaFunction - 4-3-2013 at 00:35

It seems that a huge fraction of glassware has a 10/30 thermometer adapter.

Trying to find a reasonably priced 2nd hand 10/30 thermometer is next to impossible. I managed to find one beautiful Ertco on ebay, but the seller packed it badly and I was left with shards.

New 10/30 thermometers are expensive ($60+). And Teflon 10/30 adapters for plain thermometers are rare.

Is 10/30 something that has gone out of style? Or did all the 10/30 thermometers break before hitting the surplus market? The heavy glass plug on a thin thermometer seems conducive to to breakage (eg, above Ertco).

edit: Amazon has 10/30 H-B thermometers for $45 or so, not 6$0. Still much more than the $15 you might pay for a good, certified spirit thermometer.

[Edited on 4-3-2013 by GammaFunction]

Lambda-Eyde - 4-3-2013 at 01:18

Man, this annoys the living shit out of me too. 10/30 and 10/19 joints are on every fucking short path distillation head in existence (and are still produced like this), even though thermometers, stoppers and adapters in these dimensions are nearly non-existent. What. The. Shit?

Also, what the heck is wrong with the 14/20s? European-style short-paths are always fitted with a 14/23 thermometer port...

Endimion17 - 4-3-2013 at 05:13

This is why it should be said once more - don't buy glassware (except if it's very cheap). Order custom pieces from a flameworker. It's cheaper and you can avoid obsolete glassware and expensive, stupid combinations that lead nowhere. You also help small bussinesses by paying directly to them.
Think ahead, choose your main glass joint and work around it.
NS14 is what you want for thermometers and every other "addon" such as tubes, funnels, etc.

Lambda-Eyde - 4-3-2013 at 07:04

Quote: Originally posted by Endimion17

This is why it should be said once more - don't buy glassware (except if it's very cheap). Order custom pieces from a flameworker. It's cheaper and you can avoid obsolete glassware and expensive, stupid combinations that lead nowhere.

This is either bullshit or excellent advice, depending on where you live in the world.

In Norway, with eight professional flameworkers in total combined with high wages and taxes - this is bullshit. The flameworker at my university charges just under 100$ per hour plus material costs. Comissioning something as simple as a a short-path distillation head would be incredibly expensive as well as a waste of the glassblower's talent.

If you however live in Croatia, where people are paid 5$/hour and everything is cheap as dirt, except niche glassware manufactured with German wages - yeah, then it's pretty good advice...

Dr.Bob - 4-3-2013 at 07:08

Chemists like 10/30 joints for vacuum work, as having a 14/20 adapter with a rubber o-ring thermometer adapter will almost always leak to some degree, plus the o-rings are destroyed by some reagents. Also, you can create a smaller short path with 10/30 joints, thus less hold up. The non-Hg thermometers are readily available from ChemGlass, Ace, Fisher, etc, they just cost a lot, like most science glassware. I have never had a problem, as every organic lab I have ever seen had scads of them.

The challenge is not finding 10/30 thermometers, it is finding non-mercury 10/30 thermometers, as to ship Hg thermometers LEGALLY is nearly impossible. And buying NEW, non-chinese, Hg thermometers is not very easy, although most institutions and businesses now ban them due to enormous costs from regulatory groups if any mercury is found anywhere. Many Chinese companies routinely ship them via USPS, despite that being a federal crime, since the USPS has no power in China. Doing it by FedEx or UPS is theoretically possible, but not easy, from my experience.

If anyone will be coming through NC anytime, I know where you can get some reasonable priced Hg 10/30 thermometers, as long as you deal with transport. I just can't take the risk of shipping them.

mr.crow - 4-3-2013 at 08:20

Cool, I have been wondering why I couldn't get any proper thermometers. I did find a super-expensive teflon adapter. Long story short I got some extras without proper o-ring nuts and epoxied a sealed glass tube with a thermocouple in it. Home-made 10/30 thermometer.

Poor mercury, so misunderstood

bahamuth - 4-3-2013 at 09:12

Well, I have the same problem finding thermometers for short paths, kontes bantamware reactors etc. of the size 10/30, but have like 15 all glass w/taper 14/20 (alcohol/petroleum filled) thermometers. Have a bunch of Hg thermometers too, high temp and whatnot and since they are filled with Hg I know I'll keep them in nice cond. and have them for a long time, as oposed to the alc. thermometers which are dirt cheap and it's content can be wiped up with a cloth and forgotten.

I actually have the problem of finding the 10/30 thermometers at all, or at prices like 60USD/GBP, which I don't import because of the taxes, and also since I don't care if they are Hg or not, if the value is stated as more than ~30USD the customs will open them and confiscate them.

And I agree with mr.crow, poor precious lustrous liquid metal, feared by most...

Also, Lambda-Eyde is correct on the cost on custom glassware, I can't imagine what the cost would be for a short path in Norway custom made. But I can guess, outside a University setting I'd say as high as 700USD easy. Salaries in Norway is insane...

GammaFunction - 4-3-2013 at 11:12

Quote: Originally posted by Dr.Bob

The challenge is not finding 10/30 thermometers, it is finding non-mercury 10/30 thermometers, as to ship Hg thermometers LEGALLY is nearly impossible. ....

If anyone will be coming through NC anytime, I know where you can get some reasonable priced Hg 10/30 thermometers, as long as you deal with transport. I just can't take the risk of shipping them.

On Amazon, I've found that one can get non-Hg H-B brand 10/30 thermometers for about $45. That's the best deal I've found, about $15 to $20 better than elsewhere.

Fedex shipping rules for Hg here.

Hg is not a hazmat (page 9) if it's in an instrument when packaging is prepared under 49 CFR 73.164. The relevant rule is (1), which says that a thermometer "must be in strong outer packagings, having sealed inner liners or bags of strong leakproof and puncture-resistant material impervious to mercury, which will prevent the escape of mercury from the package irrespective of its position."

At least this is what I think the relevant bits are.

[Edited on 4-3-2013 by GammaFunction]

Dr.Bob - 4-3-2013 at 14:00

That is useful, as my US post office has photos of Hg thermometers on their list of banned objects threatening you with federal crimes for shipping them. I have shipped a few via Fed Ex in the past, but was not even sure if I had it done correctly then. Since the rules in FedEx's guide are 300+ pages, you can see why I would be hesitant to sort it with them, as if you ask in the store, they will give you no lack of hassle. Thanks for looking at that.

I used to ship small samples under 49 CFR 73.164 via a hazmat group, and the rules for that were even worse, pages of rules written by the same people who brought us the IRS forms... There are just pages of rules, and details (main point I remember was that less than 35g of most things was OK, unless it was one of the many exceptions to the rule.

But if people are willing to pay FedEx's fees, I might be able to ship thermometers via them.

Endimion17 - 4-3-2013 at 14:04

Quote: Originally posted by Lambda-Eyde

Quote: Originally posted by Endimion17

The prices of ground glass joints are pretty much standardized throughout the whole Europe.
We have both domestic and import glassware and it's pretty much the same price if we forget about the taxes and differences in shipping costs.
Also don't forget that average wages aren't a good representation of the actual purchasing power. I bet the differences in Norway are much less pronounced. The gap in less developed countries is just huge.

Check this out. My flameworker can make a NS14 Liebig cooler (150 mm length) for slightly less than 35€, plus additional shipping. Sigma Aldrich charges around 38€. That's one case. Other glassware prices can be a lot more different, sometimes 3x higher.
I don't think that Liebig is very cheap, but it's much less than the money I'd have to spend if I buy it from a retailer which usually charges at least 50% more.

You don't have to hire a professional laboratory glassblower. I bet there are very skilled glassblowers out there that make bongs and can make you the same cooler for less money, though probably not much less...

My point is that the simplest solution is to buy the stuff from the retailer, but if you lack money, and we all do because this is an expensive hobby, we have to use other sources. A little effort goes a long way.

BromicAcid - 4-3-2013 at 14:17

I would wager finding them second hand is difficult because people don't just have them laying around. One full distillation setup only needs one 10/30 joint usually. You don't need them for reaction setups, and you're usually only running a single distillation at a time on home scale. So you only need that one thermometer. So does everyone else. If it breaks you get a new one, if someone is selling a large set of glassware there is likely only one in the set. Some things are just hard to find second hand. At least that is what make sense to me.

At my place of employment we usually use a 10/30 thermowell with temperature probe although we do have the Teflon adapters too. Not that eBay seems to be overflowing with thermowells either.

Funkerman23 - 6-3-2013 at 10:27

Lucky: the only adapter for 10/30 I've found is from Kantu200 and none of my thermometers would fit it( it says it would work with a 6mm thermometer but without knowing the tolerances its a crap shoot I don't want to take). I did see what looked like a rubber( viton maybe?) adapter on one of ymachtx's youtube videos but the account isn't used anymore as far as I can tell.

Quote: Originally posted by mr.crow

Cool, I have been wondering why I couldn't get any proper thermometers. I did find a super-expensive teflon adapter. Long story short I got some extras without proper o-ring nuts and epoxied a sealed glass tube with a thermocouple in it. Home-made 10/30 thermometer.

Poor mercury, so misunderstood

[Edited on 6-3-2013 by Funkerman23]

Jekyll - 7-3-2013 at 00:45

Another joy of 10/30 thermometers is that the 14/20 short path distillation head will probably need a 25 mm immersion thermometer, the 24/40 short path will be a 50 mm immersion and the basic 24/40 75-degree distillation adapter will be a 76 mm immersion.

bahamuth - 7-3-2013 at 08:50

Quote: Originally posted by Jekyll

Another joy of 10/30 thermometers is that the 14/20 short path distillation head will probably need a 25 mm immersion thermometer, the 24/40 short path will be a 50 mm immersion and the basic 24/40 75-degree distillation adapter will be a 76 mm immersion.

So true so true....