# Drilling A tank



## chris55 (Jan 11, 2009)

Can you drill a already drilled tank??? I have a 180 gallon that came drilled with 2 overflows and I am needing to drill it again, I was told not to drill but its already driled so why not?


----------



## onefish2fish (Jul 22, 2008)

first i would contact the company that it was purchased from. in every case ive hear, they drill the tank then temper the glass for strength. 

what do you need more holes drilled for?


----------



## chris55 (Jan 11, 2009)

im doing, a closed loop, and need to more hole for my darins/returns


----------



## onefish2fish (Jul 22, 2008)

i would call the company the tank was made at and make sure. 
this is an example of what happens to tempered glass:
YouTube - tempered glass drilling demo..

ive heard using a polarized film but have not tried this method
http://answers.yahoo.com/question/index?qid=20070302000201AAR8WI3

my understanding is that the bottom piece of glass is tempered in most cases.

and if you need help on actually doing the drilling there are some instructional videos on youtube. feel free to ask any questions you may have.


----------



## chris55 (Jan 11, 2009)

WOW!!! from the looks of that I think ill just build some overflow boxes and use them


----------



## chris003 (Mar 11, 2009)

Won,t try that , ha ,ha lol cool


----------

