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Old 11-09-2012, 04:20 PM
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Quote:
Originally Posted by FishyFishy! View Post
Does anyone know how to tell if glass is tempered? I'd love to be able to drill the sump to have an emergency drain.
I doubt it's tempered but there's an easy way to be sure. You need two polarized lenses, one on each side of the glass and look through them while you rotate the lenses. If it's tempered you'll see a matrix type pattern which represents the internal stresses caused from the process. You can use polarized sunglasses if you have them.

You can test this procedure on your car windows, your windshield will not be tempered but your side windows will be.
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