Testing for tempered glass for drilling

[scherzo]

I wanted to help a fellow reefer determine if he had tempered glass or not. We couldn't find any video on youtube that shows how to use polarized lenses... so I just made one..:

http://www.youtube.com/watch?v=Zp7kuKMmDg8

Hope this helps people out!

[lbaldrey]

Nice.
Thanks for sharing.