External overflow

[reeffer1]

Ok I am going to be building an external overflow and was wondering the best way to make the weir. I have seen it done 3 ways, a section of glass cut completely out, Cut out using a dremmel but leaving glass to form the screen, and by using a hole saw and drilling a buch of holes across the top. Any ideas on which way would be the best?

 

[BeanAnimal]

I like the entire slot method. Leave rounded corners to prevent areas for stress cracks. This also means a lot less corners to crack under stress (teeth method) and looks a lot better than the HOLESAW method, which may leave small chips at each hole.

Bean

 

[DHyslop]

I cut 25 individual 1/4 x 3/4" slots. Despite having more edges, I think its good to still have some of that material in there. It is of critical importance to make sure everything's perfectly rounded.

I think we would really need an engineer to answer this question, any of us can make up any reason (as I did above) to convince ourselves that our way is the best.

The two external overflows that I've heard of that failed both cut one big slot, but they were also on the back pane of glass. No matter what you do you should do it on a side pane.

It would give me a lot more confidence to do this on a custom tank with a pane of glass twice as thick for the overflow.

Dan

 

[reeffer1]

How did they fail? Were the edges rounded or square? Why do you say a side pane, I do not see how this would make a difference. With my 92 corner there areonly the 2 sides and the front.

 

[the tiler]

I am in the process of doing an External Overflow on the back of my 125Gal

http://reefcentral.com/forums/showthread.php?s=&threadid=767958

Jason

 

[DHyslop]

<a href=showthread.php?s=&postid=6671151#post6671151 target=_blank>Originally posted</a> by reeffer1
How did they fail? Were the edges rounded or square? Why do you say a side pane, I do not see how this would make a difference. With my 92 corner there areonly the 2 sides and the front.

Since your tank is a corner, neither side is stronger. However with a conventional tank, the side panes are shorter and thus less likely to exhibit strain. I don't know more details about the failed tanks, but I read about both here on RC threads. If you want to know more about them, try a search.

This is risky business, no question about it!

Dan