my lesson learned...dont drill plastic sumps

[atxcichlid]

I tried drilling holes in my dual tide pool sumps and fitting them with bulkheads (to prevent overflow in case of pump failure) i am now on my 4th tube of silicone trying to stop leaks, the plastic flexes with every inch the water rises, gaskets arn't holding up <this perfectly represents myself the past few days....drying, testing, drying, testing, now we are drying again...stick with glass or acrylic once i get this sealed i will be starting a dual 30 gallon glass sump build.... look out for pictures, you wont be hearing about leaks with this build.



expect great things soon, straight outa Austin

 

[Cashlaw]

Maybe try LocTite plastic epoxy? It's supposed to seal plastics that don't usually seal with silicone or epoxy. Or try plumber's Teflon tape / putty.

The plastic epoxy is kind of waterproof . . . waterproof for the short term, but it can degrade if kept underwater for a long time. Could use it to join the pieces, then coat that with silicone for waterproofing.

 

[KaiserSousay]

I would look to a bulkhead with a flange. larger surface area for the gasket, along with no flex.
I have always used PVC electrical fittings for bulkheads. I did have a dripper, the one time I used an "O" ring for the gasket.