good ideas here ! I'm not sure if I made it clear that the thru hull I want to replace is on the lower side of the hull, originally not at the water line, but now due to water intrusion weighing the boat down, this thru hull is at the water line. The bedding that the thru hull had was not sufficent to keep out water as the thru hull now lay in water. Water thus found its way into the area around this thru hull, an area 5-10 inches in diameter, some above the water line and some below the water line.

I now plan to use something like a bent hack saw blade. or sawzall blade to reach in and dig out the wet core. Then I will try that CPES epoxy and see where that gets me. Again, this is an area that is right at the water line on the side of the boat, not in the bottom of the boat. This thru hull leads via 1 inch hose to a drain in a deck locker.