Time to get to business. We needed to replicate the heart of this canoe…..the stem. This is the curved edge of the boat, made from solid wood that extends from the keel below to the gunwale of the canoe. Structurally it is a critical piece, that provides strength, and unites the port and starboard planks. It is also tapered to provide the aerodynamic shape of the canoe, allowing the boat to cut through the water. We are starting at the stern, where most of the work lies ahead of us.
In many instances, the entire stem does not need to be replaced. The rotted section (usually the top) can be cut off and a new piece can be scarfed in. In our case, the whole thing seemed pretty worn out, so I decided to construct a new one. We used white ash (Fraxinus americana) to create this. I went to our local Woodcraft store to select the board that I needed. It was critical to find a board that had very straight grain, either quarter sawn or rift sawn. Having the grain run straight will reduce the chance of fracturing during the wood bending process. This piece was ripped on the bandsaw and then soaked in a creek for 5 days.
In order to bend the piece of wood, you will have to create a jig (or a form) to bend the wood over. The jig does not have to be pretty, but it has to be functional and accurate. I constructed ours using lumber from a pallet. I glued these pieces together and let it dry. I would use the original stem to create the outline for this jig. It is important to note that the radius of curvature for the jig will actually be tighter than the original stem. This is because we have to account for spring-back, once the piece of wood is removed from the jig.
After the 5 days of soaking in a creek, I fired up our wood steaming box and steamed the piece of ash for 1 hour. Once the wood is removed from the steamer, you have 60 seconds to bend it onto the form before it loses it’s elasticity as it cools. This part can be a pretty harrowing experience if you’ve never steam bent – I’ve never steamed bent anything. I was very fortunate to have the first attempt succeed. For any critical part of canoe building, I often practice the motions before I actually do it. All the clamps were at the ready, my path was clear, I made sure I had enough ceiling clearance etc. I ran through the steps with a mock piece of scrap wood. I also used a piece of steel strapping to help reduce the chance of fracture.
After a week in the jig, I removed the stem from the form and began to notch out the slots for the ribs using a dove tail saw, a coping saw and chisel. This is where we spent alot of time, measuring angles of tapers to get it just right. I used a block plane to get it to the right thickness and then a spokeshave for the beveling.
In the meantime, I steam bent some pieces of ash for the 2 inwales that would need replacing. I created another small jig for these as well. I cut them roughly to size and then used a block plane and spokeshave to get it to the proper dimensions. Ash is very satisfying to work with. These pieces will need to be scarfed into place and glued together using System Three T-88 epoxy. The length of the scarf joint is approximately 4 inches to allow for as much surface area contact as possible.
One of the ribs in the stern end also needed complete replacing so we soaked some eastern white cedar boards in the creek for 5 days and then stem bent these for 20 minutes prior to bending them on the form. This step is fun because a jig does not need to be created. We have an intact hull to bend it over! As with any steam bending step, you have to account for springback once the wood is removed from the form. So in order to replace the rib that you want to fix, you actually will use the rib form adjacent to it (with a steeper angle) to bend over. These worked out well thank goodness.
So everything right now is just dry fitted and held together by clamps, the next step will be to fit the stem in place, glue in the inwales and get the ribs and planking changed at the stern. Progress! Spring has been absolutely beautiful as well and we are taking full advantage of that! Wishing everyone good health.