Robert Bonomi wrote:
In article , Mark & Shauna wrote:

You've got your 'knowledge'.

I've got first-hand experience.

Including a _catastrophic_ failure of one such panel. There was a
substantial pressure differential between 'inside' and 'outside'.
Glass shards went *everywhere*..


First of all, fish tanks have very thick glass. We had a 125 gallon
which had glass almost 1/2" thick. Additionally the pressures in home
fish tanks are trivial compared to those which would be exerted on that
of a fish tank. Did you read the other post which did the math showing
you that you would need a piece of glass which could support 26 tons? So
you are telling us the glass in your sliding glass doors could be laid
flat and support 52,000 pounds without bending/breaking.
You now bring up aquarium glass in commercial applications. In case you
didnt see it while you were there, most aquariums have a sample of the
glass they use and it is of no compare to anything relavent to this
thread. It has to not only be able to withstand the weight of the water
but a potential strike from a large occupant.
The cool inside is often the case with good double pane panels. The
"catastrophic failure" you wittnessed was because all glass which comes
with in a given distance of the floor of structure, and door glass, has
to be saftey glass, usually tempered. This means that in the cooling
process of manufacturing the glass they tension the outer skin of the
glass. What this does is put the glass itself under enourmous tension.
This tension is there so that when the panel is bent to the point of
breaking the tension causes it to shatter to millions of tiny pieces
rather than creating shards. Its a very wild process to watch for sure
and almost seems like the glass "explodes". Very loud bang, etc. It is
not an explosion, its the way the glass is designed to fail for your
saftey. It has absolutely nothing to do with the contents, or lack there
of, inside the panel.
Again, you could simply research this with any window manufacturer, or
choose to do the physics your self (most has already been done for you)
and find out that the vacuum issue is mute.


Ciao... Mark