Well, I finally got around to putting this up on my website, even though it's been 2 years since I did it!
The small opening port in the head was leaking badly wheb we bought the boat, both through the
worn-out gasket and through the bedding. I did a lot of research among sailors who had
performed successfull waterproof repairs and "borrowed" all their good ideas. Full story at:
http://www.chessie.com/boat/projects.shtml#PortIt's now been two years and this repair has been rock-solid and leak-free.
The two key points that were essential were :
1. Epoxy-fill the gap between the cabinhouse wall and the inner liner.
2. Use Dow Corning 795 as the bedding.