Hi David
I believe it is the outer bearing housing to hull joint you should be looking to try and seal.
In my view where someone has glassed over the inner bearing housing they may have just allowed the sea to flood into the fabric of the boat.
Having said that there are some stern tubes which were just glassed into the boat you may have one of those.
I would recommend taking the boat out of the water to do this job. Jobs like this can take longer than you first think.
Good luck, let me know how it ends.
Mike
Mike Edwards
Seal 28 "Aztec"
Mike Edwards
Seal 28 "Aztec"