fix for chainplate leaks
The chainplates on my 37c leaked for years. Nothing worked for more than a season or so -- not epoxy, not 5200, not tub&tile bathtub caulking -- nothing. In the course of sailing, movement of the rig would eventually break the seal between the chainplate and whatever I was using to seal things up, and water would wick down the chainplate to the inside of the boat. Eventually, I came upon a satisfactory fix based on the recommendation of a surveyor, whose name I unfortunately don't remember. The approach was to make sort of a cofferdam around the chainplate so the water doesn't get to wick down it. I found some rubber sheets about the twice the thickness and consistency of inner tubes and cut out a rectangular gasket to fit under the chainplate trim plates that screw into the deck. To get a good seal, I carefully cut a rectangular hole in these gaskets to match the chainplate cross section, using an exacto knife. I made the hole a tight fit so water can't weep down the chainplate even without sealant -- it gets shed off by the rubber gasket instead. I then gooped the bottom of this gasket up with some automotove RTV sealant, and reinstalled the trim plates with the rubber gasket underneath. For a bit of overkill, I added a second rubber gasket on top of the trim plate, gooping that down with RTV as well. But I think the second gasked really isn't necessary. I just figured I'd add it while the shroud was disconnected. If you are neat in your cutting, the installation doesn't look bad at all. I'm about 2 years into this experiment, and the chainplates sealed this way have yet to leak. Good luck.