Anybody ever had to patch a hole in the westy water tank?

I have a spot on the passenger side that looks like it got hot and is paper thin the size of a dime.
One spot is leaking . need to fill it in from the inside 

I am thinking plumbers goop?

Aquarium Silicone?

A two part epoxy weld product for soft type plastics ( some plastics do not weld like polypropylene)

Anybody been here done that?

Thanks much. 

Doug