Telling the Diff. between Tempered and Non-Temp Glass

[Jahreefer]

I want o drill 125 I got and dont know it is Tempered or not. How do you tell the difference, is it in the thickness?

[YLChik]

most say if you know who manufatured the tank try the website or a phone call toe the manufacturer...

when in doubt don't drill.. I THINK that usually on a tank that size the bottom may be tempered but not the sides.

hope that helps you!

[Loverotties]

Temper breaks up into little pieces and is hard to drill, and glass can be big pieces when broken and are sharp pieces that you can cut yourself.

[taekwondodo]

Use a hammer and gently tap the glass. Tempered glass will shatter, while un-tempered generally just cracks. Other than this, if it's not labeled it's really hard to tell.

Be sure and let us know how the test goes...

[theplatypus]

Just start drilling.If it explodes into a million little pieces you know that it was tempered.

[Daemonfly]

Supposedly you can tell by a pattern you can see with polarized light or by using a pair of polarized sun glasses.

[lemonheadmech]

Originally Posted by Daemonfly

Supposedly you can tell by a pattern you can see with polarized light or by using a pair of polarized sun glasses.

I've heard of the same thing. Supposedly it looks something like gridwork, but have never tested the theory.

Are you drilling the sides of the aquarium or the bottom? Generally the bottom piece is the only one tempered.

[Geoff]

if you have two polarized sunglass you can put the glasses on either side of a pane of glass. then rotate one of the sunglasses. a pattern should show up. i can not remember which is which so you might want to test this with a couple of different panes of glass around the house.

G~

[Bergovoy]

There is three ways to use to try to determine if the glass is tempered or not:

If the glassis unassembled, (just plate glass), you can bring the glass to a glass shop and they usually have a 'tool' that they can place over the edge, (the tool is a stiff U-shaped piece of film) that slides over the edge.

It is basically a polarazide film that will allow a trained eye to determine if the glass is tempered.

Second: You can use polorized sunglasses to look at the glass. You are looking for surface imperfections. Basically, the anealing process, (the tempereing process) melts and refuses the surface glass. And when the glass cools, there are slight surface irregularities, (pits and pimples). They are very small and will show up under polorized light.

Try loooking at a piece of glass that you know is tempered first, (the windshield of your car is a great example and will be eas to see the imperfections.

(Side note: that annealing process, changes the surface 'TENSION' on the glass so as when the glass is struck or bent, the changes in tension throughout the glass force the glass to break very quickly and into small pieces)

Third method: Use a glass cutting tool. You know the kind, the wheel roller thing. Try to make a scroe into the glass. Do not do this so the score goes all the way to the edge. The score should start and stop without going to the edge.

It only needs to be a quarter of an inch or so.

The pont you are looking for is to see if the glass can be scored. If it can be scored, it is NOT tempered.

If it CANT be scored it is tempered.

This is not as bad as it seems. you can make the score ont he back glasstowards the botto, mnaybe in the overflow area or some other inconspicous locale.


Good luck and let us know what you end up doing.


By the way, a glass shop might charge you $25-35 per hole if you bring the tank to them...

I was going to pay approx $130 for them to drill about three holes if they came out to my house to do it

Good luck