Inside, there are a few more things to do before we put on the deck. First up, the knees. The big ones are located at the front of the cockpit. These are traditionally constructed knees. One piece, taken out of a piece of hackmatack with the proper grain direction (see the pre launch post from June 2009). These guys were a challenge to fit. They fit tightly against the deckbeam, the sheer clamp, the frame, and, since they are quite a bit thicker than the frame, the planking. A total of 6 faces to get right.
There is also something called a "web knee" in the center of the cockpit. This one is made out of plywood. It serves two purposes, to strengthen the boat as a knee or bulkhead would, and also to act as the center support for the seats. We think they look like toilets.
The last pieces to make before decking are for the cockpit combing, which surrounds the cockpit and helps keep the sailors dry. These pieces are 14' x 8" x 3/4" oak which takes a big bend and twist at the front. So we'll need to steam them. They will not be installed until after the deck is on, but right now we have a lot of things to clamp to which will be covered by the deck. So we set up a bending jig right on the boat (note the carlin is the back 1/2 of the bending jig). . .
Gather a bunch of friends. . .
And voila! The next morning we can take of the clamps. Since these pieces (we did 2 separate steamings to avoid conflict at the front where the 2 combing pieces come together) won't be used for a week or so, we'll clamp them to the bench with some blocking and tensioning devices which will help them keep their general shape until we can get them permanently installed.
While the combings pieces were the last pieces to make, the last thing to do before decking is fair the top of the boat. We aimed to have all the deckbeams and blocking be a little proud of the final deck location. This way, we can put the camber gauge on a beam or a block, see where it hits, shave off a little wood, and repeat until the camber gauge sits nicely across the boat. The one rule is that you can't shave off the sides of the boat, the all important sheer line. This keeps the boat fair going fore to aft as well as side to side. A few places we had a gap in the center of the boat when the camber gauge was resting on the edge. In that case, the deck beams were too small (or we were too aggressive in our planing) and a little shim is required (see the foreground of this picture).
Once we are satisfied the plywood will lie fair on the beams and blocking, it is time for the deck, which is extraordinarily simple after all those fussy knees and bulkheads. You just lie the plywood on the boat, have someone sit on it, and mark out the edges of the boat, the cockpit, the blocking, and the beams from underneath. We can trim it later, so we don't even have the cut out the pieces all that accurately.
The deck will be built of 3 layers. 2 layers of 1/4" plywood covered by a coat of Dynel wet out with epoxy. The Dynel is the petroleum age version of canvas. Very non-traditional. One might ask after all that plank on frame stuff why switch to a more modern construction method? Turns out traditionally build decks simply do not last that long. They leak and cause problems with all those pieces we just installed (deckbeams, blockings, etc. . . ) Since these leaks are invariably fresh water in tight spaces, they lead to rot. So the decks often become the place of compromise for even the most fervent traditionalists who scoff at the idea of a cold-molded boat being called a wooden boat.
Back to the first layer of decking. This layer will be temporarily screwed down while a flexible marine glue (we use sikaflex) sets up. First we paint the bottom of the deck (much easier now than later, especially in the watertight compartments fore and aft). Remember how we scribed off where the deckbeams were? These marks allow us to tape off the deck support locations so we have a good glue surface (which paint is not).
And now some before and after pics, which caused our instructor Kevin to give me the title for this weeks post. . .
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