drilling holes in bottom of tank

[bryce.martin23]

just bought a 210 gal tank and i was wondering if these bottoms are tempered, right now there are about eight 1/2" holes in the bottom that have glass plates sealed over the top, what makes me wonder that the tank is not tempered is that the holes are not semetrical to each other. There are two sets of three holes located in the middle of the tank, on one side the hole nearest the side of the tank is drilled about 2 inches away from the side, while on the other side the hole is drilled about 6 inches away from the side. Another indicator is the fact that all these holes are not evenly spaced which hints to me like they have been drilled by a human and not a machine. I was wondering if you guys think the same

 

[cajonez]

It's possible to drill tempered glass by hand. Also, you can drill untempered glass and then have it tempered later. Just having unevenly spaced holes is not an indication of tempered or untempered glass, in my opinion.

 

[bryce.martin23]

Originally Posted by cajonez
http:///forum/post/3085771
It's possible to drill tempered glass by hand. Also, you can drill untempered glass and then have it tempered later. Just having unevenly spaced holes is not an indication of tempered or untempered glass, in my opinion.
how do you go about drilling by hand, i suppose you take a hole saw and attach some sort of handle to the top and start rotating

 

[salt210]

No you do not use a hole saw, it is a diamond drill bit. although the ones I have seen and used did look like hole saws

 

[bryce.martin23]

Originally Posted by salt210
http:///forum/post/3085952
No you do not use a hole saw, it is a diamond drill bit. although the ones I have seen and used did look like hole saws
well i called up one of my glass guys in the area and he gave me some info that may help, he told me that if the glass has been tempered that the edges would be nice and smooth like it was tumbled. I looked at the bottom side of the holes and you can see that there are very very tiny chips around the edge of the holes from the previous drilling, would this indicate that this glass is not tempered. Also talked to a local aquarium store and the owner told me that older tanks were not tempered, as this is my case.