BucketEars - Attach Chine Logs and Framing
There are a number of ways that you can join the sides of a plywood boat to the bottom (and decks). One simple method presented here is to use chine logs and framing logs.
You attach strip of wood, usually about 3/4" square to the bottom edge of the side. Then, you attach the bottom to that same strip of wood, and presto the two pieces of plywood are held together in a very strong joint. Because our boat is the same width as a sheet of plywood, both edges match up fine.
On other parts of the boat like the decks (or on boats with curved sides), the 2nd piece is usually left a little big and after the glue has cured, you trim and sand it flush.
One of the problems when making chine logs, is that 2x4 lumber often has lots and lots of knots. I prefer to use 2x6 or 2x8 lumber because it has less knots.
Often I can't use the entire piece of lumber to extract chine logs, so I will use the boards the best I can.
I end up with a lot of odd shaped pieces this way and if they are just layed about, it makes kind of a mess. Also if the boards are left to lean on something, they will start to warp out of shape. This is my current solution to storing wood.
I sort the pieces in various ways so when I need a stick of wood of a certain size, I first go to that shelf and look for something to use. If I can't find it, I always have a number of full size 2x6's on the bottom.
The plywood stands upright in a stack. I don't have a full sheet standing there in the photo, but I can put about 5 sheets there. I don't own a pickup truck, but have found a to bring home more plywood that is SO EASY. Since I carry my puddle duck on a trailer, I just take her to the hardware store and carry the sheets back on top of her.
Please don't get me wrong, if you want to have a messy garage that is fine. This is my buddy Tim Webber's garage, and he builds just as many boats as I do.
He usually builds on his driveway and then puts the parts on a trailer. Then he covers it with a tarp between build sessions.
Before nailing on the logs, I marked the sides so I could tell where I could drive nails.
I know this is a bulkhead, but I do this on all pieces and don't have a good picture of it for a side panel.
I start at the stern end because as I curved the log around, I would need the most leverage making that turn, and have a long stick to push against.
50% loss of glue is perfectly acceptable.
Use lots of glue, and clean it up afterwards with paper towels.
Better to have a little mess, than a joint that is starved for glue.
After starting the log at the stern end, it is easy to pull the side towards me as I drive the nails.
It works better if you have the panel pushed up against the wall.
At the time of this photo, I had a mess in the garage and couldn't get to the wall.
There is also another chine log laying loosly on the floor underneath the side.
That is to support it so that as I drive the nails thru the plywood into the chine log, that they will be straight in.
Presto, I have both sides framed. Notice the extra stringer - I will be using that later as a backup support for an external daggerboard trunk. I have one on each side so I can have trunks to match the variety of sail rigs that I'll be flying.
Another method you can use instead of bending the log around, is to put 3 planks along the curved edge. You can then trim them with a saw to get a rough curve, and sand it the rest of the way.
After the glue dries, stand upright and clamp together.
Now I can sand them together and smooth out the edges so the chine logs are flush with the edge of the plywood.
With the loose tolerances of the boat, it probably doesn't matter that the sides are exactly alike, but it is nice to have them together so can smooth all at once.
I have 7 different power sanding tools, and the one I use the most is a 5" disk that is chucked into my drill.
That plus a bunch of sticky backed 80 grit sand paper disks.
Nice to have plenty of sand paper on hand, that way when the paper starts to go smooth, I just slap on another sheet instead of trying to extract every last grain of sand off each disk.
