I know that most of you will probably never build a boat, but this is for posterity, so I thought I would share some thoughts on how I fit the planking sections together on the bottom of my boat.
A long time ago (or about three weeks,) in a place far far away (well, my garage isn't that far) I glued the starboard (right half of the bottom planking down. Before I glued, I tried to fit it along a line I drew that was exactly in the middle of the keel. In a perfect world that would also be where the peak of the faired keel is. Since my world is perfect, and I took an excessive amount of time getting it right, (look at the length of time between blog posts people...) my first piece fit exactly right. Now the trick is to get the second side to meet the first with nary a gap. Look it up if you don't know what it means. Because of the bend that you put in the plywood you have to start with the second piece overlapping the first slightly, then trim it back to fight tightly. I did the rough shaping for the second side even before the first side was glued. With the aft and forward edges overlapping the centerline of the keel by about 3/8", the mid section was close enough. Most of the mid section is in the centerboard area and will be routed out anyway. I put some screws in the piece at this point to hold it in place. Then I bent it into position as best I could and drew a line around all the parts that would be trimmed off.
It is pretty easy to drag a pencil along the chine underneath the planking, but up front where there isn't much clearance i had to wiggle under the boat and draw from in there. The front section (forward of the most forward frame, has to butt up against the side planking. I scribed the top edge of the chine onto the planking, then used a scrap to mark back 1 1/2". (1" is half the chine size plus 1/2" for good measure.) Then I pulled the planking off and cut out the rough shape.
This is the shape after cutting. Notice the notch along the chine side. This is where the planking pieces switch from butt joint (two edges together) to a lap joint (one on top of the other.) The side planking already has that transition worked into it. At this point I am using drywall screws on scrap 2" squares of plywood to hold the piece in place temporarily. It's important to get your locating holes right because if they are not repeatable, your fitting will be wasted energy. At this point I reintroduce the first side and work on getting the fit just right.
I worked from the aft end of the center section that fit towards the transom to start. Have I mentioned my hand plane? It is the best arm workout (read: muscle destruction) tool I have found. I used jugs of epoxy resin to hold the pieces down so it was easy to see where more work was needed. You have to take the locating screws out where you are working so make sure some others are installed or your piece will slide off the boat.
Getting closer...
And there it is, a perfect fit. On that 4 foot section. Repeat forward of the centerboard trunk and you are really getting somewhere! I fit the pieces together all the way up to the transition from keel to stem piece. Then I glued the first bottom planking piece down. I installed the battens for the port (left) side while the right side bottom was drying. After it dried (not long in SC) I cleaned up any epoxy that would have prevented a tight fit and rechecked all my previously fit parts.
Now for the chine butt joint and the centerline butt to lap transition. It turns out that 1/2" is quite a lot when you have to use a hand plane to remove it. As everyone says (through gritted teeth with their arm in an ice bath,) "I am learning to love the simple functionality of a well sharpened hand plane." That is a bunch of malarkey! Nobody enjoys that pain. And my hand plane must have a special bronze magnet in it because it shaves silicon bronze screws every time I use it. I have learned how to sharpen it more quickly though. Anyway, again you work from the back forward to get the planking to fit right. I had to use the pull saw and the rasp in the transition area because the plane can't get all the way in there. Then I worked about 8-12" as a time. Since there is more pressure at the beginning of your plane stroke the first 4" of material comes off faster than the remaining length. This pulls the whole section into alignment slowly but surely. One gotcha is that the upper edge (along the keel and stem) must be securely fastened or the butt joint will take the wrong line. This happens because the wood bends differently depending on where it is constrained at. For the upper edge I picked a point right at the end of the keel to transition from butt to lap joint. I started by rasping away the first bottom piece at the angle planed into the stem. This makes the first bottom piece an extension of the stem/ planking mating area. Then you have to cut in the angle along the edge of the bottom planking going back toward the centerboard. Again I used a rasp in the area right up close to the transition point. The angle is steep due to the angle on the bottom planking in that are.
This is the final dry fit. Everything is ready fit gluing. At some point in here you will have to wiggle underneath the boat again and check that the frames and battens are hitting the bottom nice and flat. In order to drill the pilot holes for the screws along the battens I marked the batten locations from underneath the boat also. Then I flipped the piece and drilled inside to outside, flipped again and drilled countersunk pilot holes through the planking into the battens. I really shortened the pilot bit depth because I felt that I had a lot of non grabbing screws on the other side and I haven't sen any wood splitting yet. When the screws don't grab they don't go in all the way. Then they get in the way for fairing the hull. So there it is, planking fit up in a nutshell.
Sanding epoxy makes a RIDICULOUS amount of dust. Which is really fine. And I have to dig out from under my eyelids when I take a shower. So maybe I need some goggles and a mask. And some plastic sheeting to protect everything else from looking like Cairo after a sandstorm. (ed note: I have no idea what Cairo looks like after a sandstorm.)
