Drilling a tank with water in it

[CJBDFRAZ]

I have a 180 all-glass aquarium that is full of water and I am thinking about putting in a 2inch bulk head to run a closed loop. I am sure that it can be done, but I would like to hear from people that have already drilled a full tank. Is there anything that I should watch out for, obviously I know that I would have drain some of the water out of the tank.

[5galnanoreef]

drain the tank to about 6 inches below the area where you want the hole to be. you'll need to have water to cool the drill bit and make sure you don't go crazy. i would tape the hole on the inside with painters tape, easy removable kind, and then have at it, just dont go to fast or to slow, you don't want to crack the tank. Hope this helps

[NanoReefWanabe]

i drilled my 20 with water in it...actually while it was right full of water, i added another hole to the overflow...i put RO/DI in a spray bottle and continuously sprayed the glass as i was drilling you dont have to worry about glass dust or RO/DI getting in your water as neither will hurt...but it is gonna take some seriously big Cahoonas to drill a 180 even half full of water...you may want to get someone to spray the inside of the tank as you drill as well, just make sure you keep the bit and glass cool...starting and stopping isnt really an option either....once you start the hole finish it, every time you stop or remove the bit you risk binding and chipping and cracking the glass..head to your local HD and grab a couple 55G brute garbage cans to store your water and upper rocks/ coral in...you can take the opportunity to do a nice big 30 or 4o gallon water change too, therefor you will only need 2 brutes to almost empty your tank...the less water in the tank the less chance there is of it blowing out...

i assume you are going to go Over the top with the returns?

[reverendmaynard]

Most of these have been said...

Tape the inside with painters tape. It will keep the disc that gets cut out from falling into the tank, as well as preventing some of the chipping you get when you get to the end.

Use a cordless drill with a clutch, set to the lowest setting. This way if the bit does bind at all, the bit will stop rather than break the glass.

Have a helper use a spray bottle to keep the drill bit cooled and lubricated.

Hold the bit at an angle when you start the hole to prevent "walking". After you get a groove cut, gradually straighten out.

Make the hole at least the diameter of the hole away from any edges or other holes.

[CJBDFRAZ]

Thanks for the advise and yes I plan to run the returns over the top. Do you think a single 2inch bulk head would be good enough for a dart.

[Pulp Fishin]

there are video's of guys who drilled their tanks part ful on youtube if you want to watch it done in action.

[NanoReefWanabe]

i would use 2 ~ 1.5" bulkheads for the intake of the dart...use a manifold that is 2" run the 2" right to the dart then bush the pipe down to 1.5" on the volute.. you will want to use a 2" true dual union ball valve right before the pump too...as well as one right after it...though that isnt of as much concern as the returns are going over the top and arent attached to the tank...

[kingsland]

I made a wood template and used duct tape to completely seal the template to the glass. The template and duct tape act like a dam and contain the water against the glass. Take the drill out occasionaly and flush with clean water.

[NanoReefWanabe]

<a href=showthread.php?s=&postid=13819470#post13819470 target=_blank>Originally posted</a> by kingsland
I made a wood template and used duct tape to completely seal the template to the glass. The template and duct tape act like a dam and contain the water against the glass. Take the drill out occasionaly and flush with clean water.

this is easiest if the cut outs you make are square in nature rather then round too....obviously make the square the same dimensions as the diameter of the hole saw...then water will be held in the corners and keep the bit wet..