S2 6.9 model........2 repair problems:

[John Short]

1. any one ever hear of the fiberglass "shell " around the lifting keel pulling away, making the keel thicker, like delaminating, and now binding going down and up. What's the best way to repair it?
2. starboard chain-plate is bolted to a wooden bulkhead inside the cabin, water leakage has softened the upper edge, it would be best to reseal the deck plate and replace the bulkhead, but with something better than wood, or at least pressure treated wood. Any suggestions?

 

[dlochner]

If the plywood bulkhead has rotting wood, either the bulkhead needs replacing if it is extensive or a new piece of plywood is scarfed in.

Generally speaking, pressure treated wood is a poor choice for boat building, especially plywood as it is not as strong as marine plywood. Marine plywood has more plies, which improves dimensional stability, has no voids which increases strength and uses a water proof glue so the plies will not separate. For some applications cabinet grade hardwood plywood can be used, but a bulkhead not an application I would use cabinet grade plywood on.

There are other synthetic options like Coosa and foam or honey coned panels, however this are extraordinarily expensive.

 

[rgranger]

For the chai plate question…
If the rot is only around the bolt hole… drill out the bolt hole to a diameter where you have removed all of the rotten wood. Plug the hole with a white oak dowel of the same diameter but first wet the edges with gorilla glue. Let the glue set and then drill a new hole for you chain plate bolt.
Don’t use red oak… it is much less rot resistant.

 

[ggrizzard]

I used to call the enclosure for the swing keel a "trunk".
Many years ago when I had a small trailer-able sailboat,
my "trunk" de-laminated and the keel wouldn't retract.
As the trunk was part of the hull, the trunk had to be cut off and rebuilt.
This was long before Coosa board and the like.
They used plywood to rebuild the trunk.
I sold the boat thereafter, so I don't know how long the repair lasted.
There may be less dramatic methods to fix the problem today,
like building a new swing keel, but thinner, so that it will retract.
For your sake I hope so. Good luck.