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Author Topic: Look what happened to my glass!  (Read 3338 times)

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Offline Lustrousstone

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Re: Look what happened to my glass!
« Reply #30 on: April 23, 2008, 10:20:33 AM »
See here for some info on lead leaching out of glass. It's almost certainly not elemental lead that leaches out but the soluble lead oxide compound that was used in the first place. What is measured in these tests is the elemental lead using some kind of spectroscopy.


Offline Frank

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Re: Look what happened to my glass!
« Reply #31 on: April 23, 2008, 10:27:11 AM »
Argh! Wikipedia, not great interpreters of research,
Frank A.
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Offline Lustrousstone

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Re: Look what happened to my glass!
« Reply #32 on: April 23, 2008, 10:57:48 AM »
Agreed but there are reference papers cited and more available elsewhere on the web


Offline krsilber

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Re: Look what happened to my glass!
« Reply #33 on: April 23, 2008, 08:14:41 PM »
Hi Kristi

Quote
The effect of a change of 8 psi on a solid like glass would be negligible.
- I disagree: put 8 psi into a thin walled vessel and it will explode. The extra pressure in a bubble in a paperweight will causes additional stress, which could lead to crack growth and failure, particularly with any differential heating.  Sorry, I should have been more clear - I meant without bubbles, responding to "whether they have bubbles or not."

Quote
My understanding of the effect of water on cracks is a slower chemical process.  I think once again temperature is usually to blame when things break while being washed.
- I agree that the mosy likely cause of cracks when washing would be thermal shock. But water molecules can have a physical effect on crack tip stresses, and affect the growth of the crack, and lead to failure. See the research paper I cited in an earlier posting.  I did, and I meant to thank you for posting it!  Interesting article.  The only mention of a possible strictly physical effect I saw was unexplained ("Gurney [6] then showed that moisture enhanced fracture could be explained in terms of thermodynamic concepts").  Otherwise it seemed to be about chemical effects of moisture, including humidity.

Alan


As far as lead leaching from glass goes, it seems to me that's been pretty well established. 
Kristi


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Offline Pinkspoons

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Re: Look what happened to my glass!
« Reply #34 on: May 08, 2008, 12:05:47 AM »
Argh. I've been preparing for a large-scale redecoration, and when I was putting some stuff up in the attic I noticed that a really nice turn of the century milk jug I had stored on a shelf up there had decided to split, quite violently, into three scattered pieces. The attic isn't prone to extreme changes in heat or humidity as it's well insulated and ventilated, so it's a bit of a  :huh: situation. I've got many large cased pieces up there that you would have thought would disagree with any changes before a plain clear jug.

Ho-hum.


Offline Max

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Re: Look what happened to my glass!
« Reply #35 on: May 08, 2008, 05:51:50 AM »
Very odd Nic!  I guess you'd know if you had bats...it's the guano that gives them away.   :-X



 
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Offline Leni

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Re: Look what happened to my glass!
« Reply #36 on: May 08, 2008, 07:27:06 AM »
Are you SURE your attic isn't subject to extreme changes in temperature?  (Do you mean 'attic' as in a room in the roof, or 'loft' as in storage space under the roof?)  Most lofts are, especially if the roof is insulated. My son's room - a loft conversion - goes from very hot in summer to very cold in winter :-\  I would guess your 'attic' temperatures depend on whether the roof above (or below?) is well insulated! 
Leni


Offline Pinkspoons

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Re: Look what happened to my glass!
« Reply #37 on: May 08, 2008, 08:56:33 AM »
No bats..... as close as I found was a dead sparrow, once. Never figured out how it got in.  :-\

Oh, I didn't realise there was a difference between an attic and a loft, Leni. I thought they were interchangeable. Mine's been converted into a room, but not of a liveable standard - just floored and boarded out so I can easily (and safely, I thought) store all my stock and do my product photography.

Fairly certain that the room is quite even in its temperature, as I'm always up there photographing or packing stuff. Never noticed any extremes.


Offline Frank

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Re: Look what happened to my glass!
« Reply #38 on: May 08, 2008, 09:56:49 AM »
As long as the roof is insulated and there is moving air space between the insulation and roof lining it should be OK. The breakage may just be a chance occurrence without external factors. Assuming your loft is not at 10,000 feet (3,000 ish metres)
Frank A.
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Offline Lustrousstone

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Re: Look what happened to my glass!
« Reply #39 on: May 08, 2008, 07:35:09 PM »
In Lincolnshire! More likely to be at -10 ft

 

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