one of those tempered glass questions

right....
i have taken a leap forward from my 50ltr tank and just taken delivery of a 220 ltr tank
i plan to set it up over the next six months but am straight away stuck with if the glass is tempered or not as i intend on blocking a corner off and making a waterfall with a bulk head near the top

i live in the uk and there are no safety marks on the glass and as shown in the photo the edges of the glass are slightly cut at an angle

now the sides are 6mm and the bottom is 10mm thick i have scanned the tinternet to see if it could be tempered but with no luck

any help would be appreciated

 

i've heard rumours you can use a computer monitor with a blank white screen and polarised sunglasses to tell if glass is tempered or not.
it sounds kind of odd to me and i've not yet had a reason to test it so could well be total BS.
but if youre desperate and had a known piece of tempered and non tempered glass to test this voodoo on first and see if it works or not maybe it would be worth a shot.

feel free to let us know your findings if you do try it!

 

Looking at the glass, at different angles with polarized sunglasses will show a colored pattern in tempered glass

 

You could also try a glass shop. Some of them should have a meter that will be able to tell you for sure. I have also been told that you could see a wavy pattern as you look across the glass due to the pane cooling on a conveyor.

 

thanks all for the reply,
il think il keep a diary on this one for future reference.
goin to order me a hole saw and hope for the best, i have read up that most tanks have a tempered bottom and the rest should be ok if this fails i am going to order me a new piece of glass that isnt tempered but maybe a few mm thicker and have another go....trial and error i suppose;D

 

here is somethign i found that might have useful info in it for you, as i am looking to build a tank but might help out with being able to tell if its tempered or not.

How to Temper Glass | eHow.com

 

um, maybe. Not always however. A pair of polarized sunglasses is probably cheaper than a new sheet of glass and free if you can find someone to lend you a pair...

 

got any polarized sunglasses? If so, tilt your head 90 degrees and you'll see the "sheen".

 

wooooooo. i rang my local optician today and managed to get a lens off them
my tank is not tempered will post results for all to see

i have used a computer lcd on a white screen to take the photo as my light source

the tempered glass is used from a pot lid as can be seen in photo 1 it has black lines in it but you can see the screen behind it

photo 2 is obviously the tank and all light has been removed by the polarised lens which indicated non tempered glass

i have also ordered an overflow kit from glass-holes

 

glass-holes has some awesome stuff i have one of there overflows