Bent Shaft Canoe Paddles
Bent Shaft canoe paddles allow for a more efficient paddle stroke. Double bent shafts place less pressure on the shoulder and upper body.
Bent shaft paddles need to be strong, particularly where the shaft joins the blade. This design includes a ridge that runs from the shaft into the blade, adding strength to the blade while keeping it light. The light weight and ergonomic design are particularly important for long canoe trips.
Materials
We used Sitka Spruce, quarter sawn for the shaft and most of the blade because it has the best weight to strength ration. We used small pieces of exotic hardwood on the handles. We also added sections of mahogany in the blade to add colour and feature. We jointed the wood using Titebond III waterproof glue.
Selecting the Wood
We chose close grain 2"x4"x6' Sitka Spruce because Sitka spruce is both strong and light.
Cutting and Preparing the Wood for the Shaft and Blade
The shaft sections are cut at 1 1/4" by 1/4" thick by 66"long. Each piece is cut quarter sawn and laid with alternating grain patterns.
The blade sections are cut in different dimensions. The closer the the shaft, the thicker the blade section. The outer part of the blase and typically 3/8" thick by 3/4" wide and 14" long. The section next to the shaft should be about 1 1/8" thick by 3/4 \" wide and 15" long. Middle sections can be made from mahogany to add colour to the paddle blade.
Glue Up of Shaft Using Templates and Gluing Blade Sections
Coat each shaft laminate with glue, align then clamp between the forming templates. You can also glue together the pieces for the blade one side at a time and clamp to ensure the base is flat. Let the glue dry overnight.
Milling the Shaft and Blade for Glue Up
Using a router table with a 1/2" roundover bit, shape the shaft of your paddle avoiding the sections where handle and blade will be glued onto the shaft. To assemble the different parts of the blade, start by defining where to glue both sides on the shaft. Cut the excess of wood on it and glue both sides using waterproof wood glue and clamps to hold everything together. Make sure the bottom part is evenly flat. Let dry overnight.
Cutting the Shaft to Length and Cutting Mortise for the Handle
Using the tablesaw and tenon jig, cut an insert in the center of the shaft's end that will receive the handle. This will allow you to place a piece of hardwood perpendicular to the shaft and parallel with the blade. Glue it and filler blocks in place.
Rough Shaping the Blade and Lower Shaft.
When the glue both sides of the blade are set, cut the central sections to taper toward the tip of the blade. This will save wood removal later. Use the belt sander to smooth both top and bottom of the blade. Now shape the shaft by tracing the profile of the blade on the shaft. Cut away extra wood so that the blade will fit smoothly against the shaft.
Assembling the Handle
Moving on to the handle, you may want to chose a dark hardwood wood to personalize your handle. With the chosen piece, you will create two blocks with an insert that will come and sit on top of the handle piece. Glue everything together and let dry overnight.
Shaping the Blade
Using a piece of Masonite, trace the shape of one side of the blade shape you want. Cut and shape this template. This will now be used to shape both sides of the blade so that it is symmetrical. Now begins the task of shaping the blade to that the shaft carries into the blade as a ridge that tapers as it gets closer to the tip. This is done using a zircon sanding disk in an angle grinder. Be careful, this is a very aggressive tool. Leave the tip of the blade at least 3/8 " thick for the next step. Once the general shape has been formed, used sanders to refine the blade shape.
Finish Sanding and Shaping
Giving the shaft of your paddle the last touches, use a spokeshave to marry the shape of the shaft into the handle and the blade. Smooth it with a palm sander.
Adding a Spline on the Blade End
To give more strength to your blade, you will need to place a fiberglass and epoxy insert into the tip of the blade. To do so, you must cut an insert on the edge. Then, using fiberglass strands from roving, fill the insert with glass and epoxy strands. Make sure to wear protective gloves and act fast as you work with chemical products that react rapidly. Set aside until it is hardened.
Finishing Your Paddle
The last step consist in finishing your paddle after you smooth it with hand sanding with 220 grit sandpaper. Use and exterior grade polyurethane such as Winwax. You can put up to 4 coats, waiting for each one to dry before applying the next.
The Real Last Step: Using the Paddle
Now for the last step, using the paddle. If you have opted for the double bent shaft, you will note that your upper hand remains closer to your body when paddling reducing stress ion your shoulder. Enjoy