Since my boat was out of the water for all last season, and I was replacing the bulkheads and vertical support, I unbolted the mast step and found that water had rotted some of the balsa core. It would have been nice if O'Day had not used balsa core here, rather solid glass. But whatever, what I did was keep the rain off, let it bake in the hot sun, and with a curved wire (thin coat hanger) dug out the rotted balsa I could reach. I let it bake for much of the summer, then I injected epoxy in and let the core soak it up several times. (Before I did this I caulked the mast step thru bolt holes with silicone from the bottom. You have to make sure the silicone goes up past the liner, but no more. If you go too little you'll be pouring endless epoxy between the cabin top and liner). When I could inject/pour no more, over several sessions, I let it cure and re-drilled the mast step holes. Now if they ever leak, the moisture will not reach core. The mast wire was/is a problem as it was not done very well. Instead of feeding thru the hollow bulkhead rib, they smashed the wire between the liner and cabin top and fed it up thru a hole in the deck. Again, another place for water intrusion to the balsa core. I fed new wire inside the rib on the aft side of the bulkhead, through a new hole. I did the same thing with epoxy so now the mast wire feeds thru solid epoxy, and if it leaks, I won't like it, but at least it won't be ruining the core of the cabin top.
