There appears to be more bad wood and rot than I thought previously. The inside stem wood has split in the area just forward of the stem/keel joint. It also looks pretty black. Also, the area on the stem that has split (about 18 inches long at the lower end) either has pulled apart or had rotted away, leaving a "slot" about 1/8" wide down the center. From inside the boat, the stem didn't appear to be bad and there is no crack showing through. If I put a screwdriver into the slot (on the bottom)and pull sideways, the gap widens and the two plywood garboards push apart.
It looks like I'll have to scarf in a new stem section. Since I will also have to scarf in a new piece on a bunch of ribs (the part near the keel), I am thinking that I should just remove the garboards to make the overall job easier. Then I could inspect the entire keel/sister area along with the rib ends. Since the rib ends are screwed into the keel sisters underneath the plywood, this makes rib end replacement easier.
The plywood garboards seem to be in very good shape, excepts for some minor delamination in a few spots on the top layer inside. It would also be much easier to scarf joints when there is no plywood against the piece being scarfed. Sanding the pieces (plywood, ribs, keel, etc) on allsides and finishing them would also be much easier.
To remove the garboards, it looks like I have to remove the screws along the joint of the garboard and the last lapstrake, and also a whole bunch of nails that hold the garboards to the keel.
My questions are:
1) Has anyone removed the plywood garboards and then reinstalled them later?
2) Are the brass machine screws (at the lapstarke joints) that have nuts peened over to keep the nuts from unscrewing? If they are then it will be much harder to remove them.
3) When I put the garboards back, what sealer should I use at the lapstrake joint? 3m 4200? Life Calk?
4) In the event I have to replace sections of the plywood, can I just scarf in new plywood? If I replace the whole plywood garboard, is it a complex steam-bent shape? It looks like the garboard is just a gradual twist in the plywood. The length of the garboard is about 14 1/2 feet.
This project has become much larger, but I want the structural repairs to be properly and permanently done. It's tempting to do a "temporary" repair so I can get the boat in the water sooner, but I don't want to do that even if it means missing this boating season

Thanks
Steve