Fiberglass tub drain keeps leaking...

[rob weaver]

I've got a Fiberglass tub, cannot get the gasket to seal at the drain. Keeps leaking from below, thus cause our floor to rot underneath. Seems like the drain opening isn't level. Is there any way to fix this? Would sanding or JB WaterWeld work?

 

[breplum]

Fixing leaks is primarily observational. If you post high quality pictures someone here might be able to contribute suggestions.