Well i asked the guy about that, and was told they are actually not 'sealed'
but there is no reason for the gas to leave. Argon does not expand and
contract, so therefore the cavity does not 'breathe'. ?? Who's to say?
And how could you ever prove it was gone? G

s


wrote in message
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i seriously wonder how long any gas remains sealed in?

windows move, shake, and are subject to wide temperature changes.