Leaking Overflow Box

[CoralsAddiction]

I recently drilled a 75 gallon tank. Upon running a leak test for the overflow box I noticed that there was a leak. The strange thing about the leak is that it starts before water reaches the weir. It appears that the water goes up behind the overflow box on the inside and starts leaking water into the bulkhead. Also notice the leak is inside the overflow box. There was no leaking on the outside of the tank.
Just looking for feedback for safety tips and how to fix the problem.
Thanks

 

[CoralsAddiction]

Just some pics

 

[lapin]

What sort of overflow box is it?
The weir is on the inside then water goes thru the bulkheads to the box on the outside?
Are there gaskets between all surfaces?

 

[CoralsAddiction]

What sort of overflow box is it?
The weir is on the inside then water goes thru the bulkheads to the box on the outside?
Are there gaskets between all surfaces?

Guess I used a wrong term. Meant to say before it reaches the "teeth" of the box. There are gaskets inside the black overflow and between the clear box and glass. No gasket at the start of the threaded area if that makes sense.

 

[lapin]

Its a normal add-on overflow.
This can be a problem and usually resulting in water on the outside of the tank.
I think the weir seal is good on the tank side but leaking on the weir side Black box side.
You can try to take it apart and put some silicone grease ( not sealer) on both sides of that gasket and re-tighten it. This will allow the gasket to slip a bit between both surfaces without deforming the gasket.
Do not over tighten or you will deform the gasket.
You can also check for small rubber nubbies on the surface of the gasket. Sometimes this happens in the manufacturing process.

 

[CoralsAddiction]

@MarineDepot Elite overflow box requires an extra gasket. I solved the leak issue by placing a gasket within the tank between the black box and the glass. Basically the same problem as this:

How to install Elite Overflow Box

There were no directions included with the overflow box i received. Seems straight forward enough except for the tank gasket placement. The bulkhead gasket on the flange side is already in place so no worries there. That leaves one gasket left. I would assume it goes between the tank and the...

www.reef2reef.com