Drilling an acrylic bottom...how close is safe?

[Fizz71]

I have a 240g (8'x2'x2') with the overflow at one end in the middle of the wall. This overflow has 4 holes drilled through the bottom of the tank.... I haven't tried to measure but 2 are large for draining and 2 are small for returns.

I want to drill another 2" bulk head OUTSIDE the overflow (so it has the whole water column on it) but as close to the overflow as possible. I don't want to hurt the integrity of the tank so I'm not sure how close is safe.

It will be part of a closed loop with 4x1" returns way down at the other end of the tank. I'll be using all schedule 80 bulkheads for holes outside the overflow.

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
x
xxxxxx
x------x
x--O--x
x------x
x-o-o-x
x------x
x--O--x ???
x------x
xxxxxx
x
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx


O =is a big hole,
o is a small hole
- is inside the overflow
??? is my new 2" bulkhead hole.

TIA

--Fizz

 

[flyyyguy]

since you are getting ignored here...Ill jsut say that I have drilled many a hole in decent sized acrylic tanks with just enough roomn for the bulkhead flanges to fit inside the panel with no issues

 

[Fizz71]

<a href=showthread.php?s=&postid=13021836#post13021836 target=_blank>Originally posted</a> by flyyyguy
since you are getting ignored here...Ill jsut say that I have drilled many a hole in decent sized acrylic tanks with just enough roomn for the bulkhead flanges to fit inside the panel with no issues

Thanks. I was feeling ignored which means I'm either completely out of my mind about worrying about it, or it's a serious issue and nobody wants to take the chance to comment!

 

[stunreefer]

I dont think youd have an issue at all, like flyyyguy said as long as the bulkheads fit.

Honestly I dont think it will hinder the tanks' integrity any more than a hole somewhere else in the bottom. There isn't a seam there really, its just where the overflow is attached to the bottom. Even if you were to drill near an actual seam, with acrylic I dont think its a problem.

FWIW, I've drilled acrylic a few times now, and its pretty easy.

GL and HTH!

 

[pwhitby]

When I have drilled acrylic I get one of those little drill presses that fits on the drill itself and holds the drill at a perfect 90 degrees. It makes it really easy to drill and ensure the hole is square to the acrylic.

I also drill a pilot hole then use the hole saw and cut from both sides to ensure the acrylic doesn make burrs which may affect the seal.

Good luck!

Paul.