Help with leaking overflow box

[mlivvy]

I purchased a marine depot overflow box which is pretty much a clone of the eshopps eclipse. The only difference I found was that instead of 3 gaskets like the eshopps it only comes with 2. According to the marine depot instructions, the gasket goes on the outside before the external overflow box. I tried it this way and it wouldn’t stop leaking. So after reading numerous threads here with others having leaking issues with the eshopps, I went out and purchased a another gasket. I did the 2 gaskets inside the tank so overflow-gasket-gasket-glass-overflow. It stopped leaking and I jumped for joy but, 1 hour later its leaking again. I took it apart for the 10th time and realized that the hole I drilled has a larger than usual chip out. Could this possibly be my issue? Should I silicone it?

 

[JoshH]

Like the eshopps overflow it should go inside of overflow flange, gasket, Tank, gasket, outside overflow box