MagicJigPipe
International Hazard
Posts: 1554
Registered: 19-9-2007
Location: USA
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Mood: Suspicious
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"Reagent" Bottle Cap Specifications (GL32 and GL45)
Okay, I have many bottles from Fisher and other unknowns that need caps. I have no idea what the specifications are for those two thread formats I
mentioned in the subject.
Here is a table with the measurements of the threads on two different types of bottles I have (all in mm):
Type 1 (2 bottles averaged):
Mouth ID: 23.3
Mouth OD: 31.5
Mouth ID to OD of threads: 6.9
Bottom to top of threads: 11.4
# of thread revolutions: ~> 2
Distance between threads: 2.20
Mouth OD with plastic ring: 34.4
Type 2 (Fisher for sure; brown glass):
Mouth ID: 26.3
Mouth OD: 34.0
Mouth ID to OD of threads: 5.2
Bottom to top of threads: 10.6
# of thread revolutions: ~> 2
Distance between threads: 2.24
Mouth OD with plastic ring: N/A
Are either of these the standard GL32 or GL45 sizes? If not, how could I go about ordering some caps for these? I ABSOLUTELY cannot afford to pay $72.79 for a (explitive) 500 mL glass bottle! I don't care that these are made with some sort of "special USP glass", this is one of the biggest
ripoffs I have ever seen (it is that way with almost all major science equipment manufacturers/suppliers; things seem to be marked up at
least 25% above the actual value of the product). And that's on eBay, not in some catalog.
Thanks in advance for any help. I have been struggling with the reagent bottle problem for years. I can't afford good ones and the decent ones I can
get have no lids (and they're all 2 and 4 L). I guess I could just buy one of the Wheatons every year and by the time I'm old and grey I'll have 30
or so.
Ground glass bottles are out of the question for a lot of the chemicals I have.
"There must be no barriers to freedom of inquiry ... There is no place for dogma in science. The scientist is free, and must be free to ask any
question, to doubt any assertion, to seek for any evidence, to correct any errors. ... We know that the only way to avoid error is to detect it and
that the only way to detect it is to be free to inquire. And we know that as long as men are free to ask what they must, free to say what they think,
free to think what they will, freedom can never be lost, and science can never regress." -J. Robert Oppenheimer
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peach
Bon Vivant
Posts: 1428
Registered: 14-11-2008
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Mood: No Mood
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The GL number is OD between the tops of the threads in mm.
Like this;
Cobert Associates
There are a few places selling the caps online. If you go to google images and search for 'Gl45 cap' and variations on that, it's usually the quickest
way to find online stores with them since it shows up the product image and you can see it's the caps themselves straight away.
So one price that I immediately saw was $30 for a pack of ten, $3 a cap.
Baffcat on the UK eBay has some if you're having trouble getting accounts with lab suppliers. I've bought hundreds of pounds worth of stuff through
him so he's fine.
These more expensive bottles you're spotting are blown from borosilicate as opposed to moulded from standard glass, to get rid of the moulding seam
and make them less prone to leaching, which means it's going to be more effort to make them. They get used to hold solvent for HPLC and analytical
reagents using special multiport caps. Or put on roller mills to agitate cell cultures where the seam would make for a bumpy ride.
If you're only using them to hold regular things on the shelf, you should look at Winchester bottles, the standard moulded amber bottles suppliers
use. Photography stores sometimes sell them and they're a lot cheaper. Some of these also use GL caps.
Here's an example from the UK, £1.92 for a 500ml bottle.
Alternatively, there are a lot of HDPE bottles on eBay. Those are good enough that I have received numerous bottles of acid, base and solvent in them
from registered suppliers. HDPE is more likely to be leached by the contents, but if the contents are commercial purity it's not really a big problem.
You can always redistill things like solvents before use, which is still done in research laboratories where they'll assume the bottled solvent is
contaminated or damp to begin with; e.g. they'll buy supposedly 'dry' solvent and then distil some from sodium before use.
[Edited on 26-3-2011 by peach]
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