Help fixing a second hand tank

[Ag6594]

I bought a 40 gallon tank second hand. I had a corner overflow as you can see in the picture. Problem is it’s leaky.

The bulkheads are sloppily siliconed in so I have some work to do to get those right.

I will scrape off the silicone and clean it as best I can. Once it’s clean should I do a Normal bulkhead and screw it in or is it recommended to silicone in like it already was for a corner overflow? I’ve only ever had external overflows so this is new territory for me.

 

[USN74NMCB]

I have a 180 gallon reef ready tank with two corner overflows and there is no silicone in the bulkheads flang side has gasket under it and nut goes flush against bottom of tank hand tight plus a quarter turn never had any leaks

 

[exnisstech]

I've always been told no silicone on bulkhead gaskets. As sloppy as that looks I would guess someone did it to try and stop a small leak instead of resealing it with new gaskets. I'm guilty of it.

 

[mfinn]

I would remove everything in the overflow, clean it out down to clean glass. Get the right size bulkheads and use on the supplied gaskets.
They slip in with little to no wiggle room and the nut tightens them, compressing the rubber gasket and getting the water tight seal.

 

[mfinn]

I will scrape off the silicone and clean it as best I can.

Almost clean isn't good enough. It's got to be squeaky clean.