Looking to add an internal overflow to a 180

[John08007]

I have an undrilled 180g that I wanna drill. I was originally planning on adding one of the ghost type external overflows but am now reconsidering it. The tank will be up against a wall making it impossible to ever remove the overflow or bulkheads without emptying the tank. Now I'm thinking about having some 1/2" glass cut to make an overflow center back. My idea is to come out say 4", across 8-10" and then back 4". Thinking if I make the front piece about 2" shorter I can then make a black plexi u shape to fit around the glass with a weir at the top. I feel it would be better to make the overflow out of glass because of the silicone bond vs plastic-glass.

Anyone ever do anything similar? Pics, suggestions?

 

[BaliReefBox]

this is exactly what i am in the process of doing on my new 120. glass external box 8-10mm and a "U" inner out of 5mm black perspex about 14-16" long but only an inch thick. I only want to drill one overflow/outlet in the back pane and it will be 63 mm, after looking at the flow for an 63 mm hole it should be enough. I will also get some 2mm strip out of perpex so i can adjust on the front weir teeth to regulate the flow, like a slider up and down

 

[John08007]

this is exactly what i am in the process of doing on my new 120. glass external box 8-10mm and a "U" inner out of 5mm black perspex about 14-16" long but only an inch thick. I only want to drill one overflow/outlet in the back pane and it will be 63 mm, after looking at the flow for an 63 mm hole it should be enough. I will also get some 2mm strip out of perpex so i can adjust on the front weir teeth to regulate the flow, like a slider up and down

I'm just not too sure of the plexiglass to glass bond with silicone, I've had it peel away from baffles in a diy sump. That why I thought it would be better to make a glass box with a plexiglass cover that would slip onto it.