Notching glass for external overflow

[reeferfulton]

Originally Posted by Trevor W

Just curious if anyone has notched a pane of glass for an external overflow using a dremel. If so any tips or advice?

Also I know that the depth of the notch will determine the height of the water but how high will the water rise above the bottom of the notch when you put some 1/4" spaced acrylic teeth infront of it. Hope that isn't a dumb question hahaha

not sure on how to notch glass.

but i had the same questions in regards to overflow teeth requirment and how high the water would rise going through them.
I believe RC has a calculator for determining flow through overflow teeth.
What i discovered was ... it really depends on your return pump and overflow design. try and find that calculator and see what it says .

I believe thats why some people have a valve to restrict there return pump. to help them adjust water height. .

For me , when i fired my tank up with the mag 9.5 , i found that my teeth and overflow combo was to restrictive and forced the water level way up the teeth.. I broke a few teeth out and the level dropped

[Myka]

Egg crate restricts flow a lot less than teeth do. Personally, I would do a horizontal 3/8" slit instead of teeth or egg crate. Easier to do, looks better, and doesn't restrict flow like teeth, or to a lesser degree, egg crate does. You can use the same linear length as you would with egg crate. The only thing you have to consider is to not buy snails that are smaller than 3/8". You should be making this same consideration if you used egg crate on the overflow.

[mark]

on reefs.org there's a overflow capacity calculator that gives height above lip.

For notch take a look through Dez's build. Also seen pictures where you drill will hole saw, connect bottoms of the holes for the lip, then up the sides to top. The radius so no stress in corners. |0___0|

[toytech]

I bought some tile cutting carbide bits and the flush cutting head adapter so it sit flat on the glass .Clamped a straight edge to the tank and cut away. I had a garden hose running on the glass the whole time , its slow and very noisy but not hard . The glass will crack when you get to the end of the cuts if you don't support the piece being cut out

[Trevor W]

Originally Posted by reeferfulton

not sure on how to notch glass.

but i had the same questions in regards to overflow teeth requirment and how high the water would rise going through them.
I believe RC has a calculator for determining flow through overflow teeth.
What i discovered was ... it really depends on your return pump and overflow design. try and find that calculator and see what it says .

I believe thats why some people have a valve to restrict there return pump. to help them adjust water height. .

For me , when i fired my tank up with the mag 9.5 , i found that my teeth and overflow combo was to restrictive and forced the water level way up the teeth.. I broke a few teeth out and the level dropped

Thanks for the info!

Originally Posted by Myka

Egg crate restricts flow a lot less than teeth do. Personally, I would do a horizontal 3/8" slit instead of teeth or egg crate. Easier to do, looks better, and doesn't restrict flow like teeth, or to a lesser degree, egg crate does. You can use the same linear length as you would with egg crate. The only thing you have to consider is to not buy snails that are smaller than 3/8". You should be making this same consideration if you used egg crate on the overflow.

Thanks Mindy! I never thought of just cutting a horizontal slit for the overflow. Have you talked to anyone that has done this method and used it for an extended period of time? Just curious if there is any draw backs to this method. I think this would be a really clean look.

Originally Posted by mark

on reefs.org there's a overflow capacity calculator that gives height above lip.

For notch take a look through Dez's build. Also seen pictures where you drill will hole saw, connect bottoms of the holes for the lip, then up the sides to top. The radius so no stress in corners. |0___0|

Thanks for the link! Thats what I was initially thinking of doing. cutting the corners with my hole saws and using my dremel to cut the straight lines and supporting it with tape as I go. Was also given the idea by Andy on the canreef facebook page to use my angle grinder and a diamond cutoff wheel.