How to check tempered glass with polarized glasses

[Scooter21]

I have read and watched videos about checking for tempered glass with polarized glass and an lcd screen. I tried with some polarized glasses and various screens I had around the house. I tried on known tempered glass and known non-tempered glass and I never got it to work 100% correctly.

I'm assuming my glasses or lcd screens are not correct. Anyone have any idea what I'm doing wrong? I read that it works better with OLDER lcd screen. I tried some old one but couldn't get it

 

[Red_Beard]

Did you try multiple angles? the polarizing lenses sometimes make rainbow much more obvious if you rotate either them or the glass 90 degrees. if you want to check the glasses, go put some on and look at/ through your car's door window. You should see a little rainbow effect as well as a pattern that shows up in the glass. If you don't see that, your glasses are likely not polarized.

 

[Scooter21]

Did you try multiple angles? the polarizing lenses sometimes make rainbow much more obvious if you rotate either them or the glass 90 degrees. if you want to check the glasses, go put some on and look at/ through your car's door window. You should see a little rainbow effect as well as a pattern that shows up in the glass. If you don't see that, your glasses are likely not polarized.

Ya. I tried rotating every which way. They'd get dimmer and brighter, but never go 100% dark. The glasses have "polarized" stamped right on them.

 

[Red_Beard]

Nah, they dont go 100% dark. if you see them dimming and brightening then they are polarized. normal lenses don't do that. It is a little more subtle that a 100% dark kina thing.

 

[C4ctus99]

So, checking this myself with polarized glasses, on my truck window it showed almost vertical bars alternating orange and green bars that stay in place as I move the phone.

This is with my phone up against the glass with a white picture and the sunglasses on my eyes. The colored bars are about 3/4-1” wide and consistent.

When I checked my tank, this was not there at all, does that mean the side walls I checked are not tempered?

 

[C4ctus99]

I take it back, there are faint horizontal lines, the ones on my truck are noticeable horizontal lines. Side panel I couldn’t find any

 

[taricha]

For the sake of my curiosity, could somebody link one of the videos or explanations that people are using for checking the polarization of a pane of tempered glass on their tank?