tempered glass, or not? failed polarizer...

[phishphood]

So no significant viewable difference using a polarizer filter looking at my tank. Should I assume it's safe to drill then? No other discernable markings, tank was bought used from a fish store closing down. I'd guess it came from an East coast mfg maybe since it's a 40 long? Any other tests I can try?

 

[porksmash]

Before I was comfortable drilling my tank I did the polarized filter test on a piece of glass I absolutely knew was tempered. I had no idea what I was really looking for so seeing that wavy light/dark pattern on the tempered glass helped me gain a lot more confidence. Other than that, I'd say go for it!

 

[sfsuphysics]

You think the polarizer will do something? I know there's a polarized view when sun is shinning on tempered glass at certain angles (most notable car rear windows), not sure that trick works if there isn't the right angle that sunlight is hitting it though.

As to the test, start drilling if it doesn't shatter you're good to go!

 

[h20player101]

Rotate the polarizer 360° on a flat plane, it has do do with lines running parallel in the glass as to the polarizer. It even works with computers.