# Drilling a filled tank



## rickcasa (Dec 7, 2011)

How stupid is it to do this? Is the risk of cracking the tank more when filled than empty? The desired hole will be for an acrylic internal overflow 5 inches from the rim. I figure I start drilling with a full tank (keeps the glass cool) and as I get closer to breaking through, I'd drain the water to about 2" below the hole and finish the job.


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## J_T (Mar 25, 2011)

rickcasa said:


> How stupid is it to do this? Is the risk of cracking the tank more when filled than empty? The desired hole will be for an acrylic internal overflow 5 inches from the rim. I figure I start drilling with a full tank (keeps the glass cool) and as I get closer to breaking through, I'd drain the water to about 2" below the hole and finish the job.


Drain it under the hole first. The pressure on the glass could cause you some issues. And it has been done before.

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## rickcasa (Dec 7, 2011)

So it's ok to drill without cooling it with water?


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## J_T (Mar 25, 2011)

rickcasa said:


> So it's ok to drill without cooling it with water?


Oh you still need to cool it! Playdough dam under the spot you'll be drilling to catch the water, and a helper with a spray bottle! All you'd need.

Posted with my Xperia, using Tapatalk 2


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