Tank Drilling ?

Ok, here is the deal...I am trying to upgrade my system.   I was wanting a 29gallon frag and a 29 gallon refugium.  I got the bits and starting drilling, however I ran into some difficulty.  I ended up drilling 3 tanks, all 29 gallon and they shattered like a spider web.  I had asked several people before I started drilling if 29's were tempered and everyone didn't thinks so, but after drilling I am starting to think they are.  I did drill another tank...the 4th one is also a 29gallon and had no problems with it, not to mention I drilled another 29 at the tank drilling session in CR last year.  I have drilled other tanks without any problems.  So, I am wondering has anyone tried drilling a 29 gallon tank?  Did you have any problems?  Are some or all 29 gallon tanks tempered glass?  Or did I just have bad luck?  I made sure I went slow and not to apply too much pressure...so I just was wondering what you opinion is.

 

yes, I did...I had the putty and water as I did in the tank drilling session and someone on hand watching to see when it started to drill through and to refill water constantly. I did follow the procedure as we did in the tank drilling session. As mentioned above, I have drilled many other tanks previously and had no problem. Just having a problem with 3 out of the 5 29 gallon tanks and just wanting to know if anyone else has had problems with 29 gallons tanks?

 

I don't think that you can drill tempered glass. The 3 29g tanks that spider webbed on me most likely were tempered. I know that the last one i did go slow and still didn't make it. I don't know what brand they were bought used.