Hello capta,
If you are talking about a shaft strut that would house a shaft bearing I might have some information you can use. We have owned several O'day sailboats, and since the companies were "related" this might help.
On our 1979 Oday 30 the shaft strut was attached using 4 large machine screws that threaded into nuts that were epoxied within the hull. There was nothing visible from inside the hull. On your larger boat there may be a plate within the hull instead of the individual nuts that were in our Oday. As often happens 3 came out with some grunting and turning on a large Phillips head screwdriver. Number 4 was less cooperative. That nut turned within the fiberglas of the hull and had to be "surgically removed".
All the work was done from under (outside) the hull in order to remove the strut and the cuttless bearing which had to be cut in thirds to tap out the long pieces. (But I digress!)
To replace the nut that had turned in its location I used a thickened epoxy to rebed a new nut in place. Positioning the nut properly was done using the holes in the strut as a guide and putting the three originals in first. Keeping the epoxy out of the threads of the nut was accomplished by packing plastic wrap into the threads. I think I used six-10 epoxy because of its thick consistency. Replacing the machine screw went OK, although it didn't just slip right back into place.
I hope this is helpful, Phil
