The (Ply)Wooden Boat, Part III: Construction

We the boat materials purchased, I returned from Lowes. Back in the driveway of the cabin we stay at I set up the saw horses (to realize I’d miscounted 2”x4” and only had enough to make them 24” wide) and got to work.

First I sat on and “tested” one of the plywood pieces which I had ripped to about 30” (I think that’s right, but I should have taken notes) to make the bottom of the boat. I wanted to go wider than the 24” that did in order to displace more water and provide more buoyancy. I sat on that piece and pretended to row, testing that it was an appropriate width.

Once I had settled on the width I reviewed the boat bottom with my cousin Robert (who was kind enough to help record the video along with my cousin Nick) we decided that it should have some taper to it at the bow and stern. I marked out the shape with the chalk lines and the casket shape of the boat was arrived on.

The next step was to install the battens which fit where the sides meet the bottom. I used a scrap of CDX to mark out the width of the sides and then used relative dimensioning to size the batten pieces. Each batten piece was sat in a double bead of M-1 sealant and screwed to the base using the Kreg screws.
Robert carefully considers the shape of the hull.
With battens installed, I cut the sides. Because of the casket shape I couldn't simply use a single, flat side piece as the boat had. Rather than make three (3) pieces per side and have that many more battens to install and joints to waterproof, I simply made kerfs in the inside face of the walls at the angle changes. When the sides were screwed to the battens, they formed around the shape of the bottom (though the cupped in slightly at the top).
Once the base was cut to size, the sides where the next to be assembled..
Next came the stern, which was a simple square piece of CDX. Because it was square, I used it to help fight the cupping that bending the sides had created. The stern was installed by seating it in more M-1 and screwing into battens between the stern and bottom and the stern and sides.

The bow was installed similarly, though because it was installed at 45° to the bottom it took a bit more fudging to install and had much more cupping of the sides to deal with.
With the sides, stern and bow installed, it was time for a snack.
Once the sides were all attached, I installed a batten around the top outside edge to stiffen the sides and provide a lip to hold and carry the boat with. I also installed a batten across the top from side to side. This batten was to hold the sides apart and further reduce the cupping at the top of the sides that had resulted from bending them around the casket shape of the bottom.
Some gentle clamp pressure helped un-bow the sides so that I could install the cross batten.
The last step of construction before waterproofing was to add a keel. My keel is relatively small and oddly constructed. The bracing all around it was necessary to avoid screwing into the ⅜” edge of the plywood. At home, I probably would have dominoed it on. On vacation I had to settle for the Kreg screws (but no Kreg jig) I had brought with me.
Dyami PlotkePlywood Boat, Plywood