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Drilling Acrylic Tank for Bulkhead

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Oct 30, 2006
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I need to drill two holes in my 29G (full) acrylic tank to put in an overflow and return.

I purchased one of the glass-holes nano overflow kits. However, I realized I should have checked regarding drilling the hole for the bulkhead. It came with a diamond hole saw for cutting glass - can I use this on my acrylic tank or is it just going to melt and gum up while I'm trying to drill?

Also, this is an existing/full tank.... so, I'm planning on draining about 1/3 of the water out to drill the hole. Not sure if anyone has experience with this that could provide some pointers.

Thanks!
George
 
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Nov 6, 2005
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Just use a regular hole saw like for drilling wood. You need to clear out the chips.

The diamond one will gum up.
 
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If you need a hole saw LMK, I'm in San Francisco.
Have a piece of wood on the opposite side of the drill (drill from the outside), keep pressing on it or if you have a way to clamp it that will prevent acrylic to go into the tank.
 
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Thanks Mario.

Where in SF are you? I'm in the Marina. If you're close I might take you up on the offer, but otherwise I'll probably just buy the hole saws I need.

I need a 1-3/4" and 1-1/8" (for 1" and 1/2" bulkheads)

GC
 
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Sep 16, 2008
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your gonna be able to drill from th outside, on a full tank? is it against the wall?

its gonna get messy if you drill from inside, but it can be done.
note:
some of the shavings will float (easy to catch/remove)
and some will sink difficult to remove.

what ive done is duct tape the long edge of a huge towel along the back glass, and up on the sides of where your drilling, and let it "float" on the top of the water..
hold up the side of the towel toward the front of the tank (a helper or two needed)
then drill... most if not all will make it in to the towel.

good luck!
 
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It's against the wall, but only a 29G. It's sitting on felt pads on a hardwood floor and slides out pretty easily and I was going to drill it form the back. Also, it's an acrylic. So, not the same issues as drilling a full glass tank, though I know there is cracking risk if too close to the edge or too fast. Thanks for the idea with the towel. If I can't figure out how to clamp a board on the inside (lip doesn't leave much space), I'll tape a towel to catch the shavings.
 
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ha, one of the ways I was able to clamp a thin board down over a lip was to use the magnets left over from an upgraded vortech mp40, the magnets hold extremely well, especially if you have a couple sets... just an idea, maybe some rare earth magnets from a hobby shop can help you out...
 

tam

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Duct tape on the inside should keep acrylic bits from falling into the tank/water.
 
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It does help to keep the shavings out, the tank you got from me I used a backing piece of wood clamped so the cut was cleaner. If a C clamp does not work, try a clamp/spreader like the Irwin type from the inside; two pieces of wood will be needed and slight pressure only while using the spreader (clamp).
 
G

GreshamH

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Drilling a full acrylic tank has more issues given how they are constructed. They are typically flexing more then glasd.
 
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Thanks all for the suggestions. I drilled the tank this weekend. Used C-Clamps with wood on the inside after draining out 1/3 of the water. Had a little scare when the hole-saw jammed in the hole and I had to tap it out lightly with a hammer. Everything seems to be in good order and I installed the bulkhead and overflow which is now up and running.
 
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