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Saturday, September 20, 2014

Canoe Building Detour: The Bent Shaft Paddle

It's been a while since I've posted an update on how my canoe is coming.  Quite frankly, it's not.  I put it on the back burner while I worked on building a canoe paddle.  Putting the cart before the horse, or the paddle before the canoe- I know.  It was a deliberate detour to give me some woodworking experience on a small project before jumping in to a larger project.  I figured that the paddle would also give me experience with laminating, a technique I will need when I make the stems for the canoe.  Actually, building a canoe paddle is a project that's taken 3 years.  Back in 2012 I cut these wood strips as a starting spot, but never got further than cutting the strips on a friend's table saw.  We've hauled them around ever since and my wife has gently nudged me toward completing the paddle, just like I've "encouraged" her in the past to complete other projects.  We're good for each other! 

I started out with some alder and poplar wood scraps that I obtained from a cabinet making shop in Utah.  If you ever need wood scraps, just stop by a cabinet or woodworking shop and most likely they'll be glad to give you some of their waste wood.  Then I cut them into strips with my friend's table saw, then put them aside for a few years.  (I actually had enough strips for two shafts, so I made two attempts at laminating the shaft.)  At work earlier this year I was talking to a woodworking subcontractor about my interest in making a cedar strip canoe and since he'd made several strip kayaks, he offered me use of his shop.  The strips I'd cut were a little thick, so I called up Chris and went to Bisbee and ran the strips through his awesome machines and ended up with several strips that were all 0.17 inches thick- perfect for stacking 7 of them to get to 1.25 inches- the diameter I wanted for the shaft of the paddle. Basically, that's all laminating is- stacking thin wood strips together and gluing them to get a larger piece of wood.  I had part of an old 2 x 10 and I marked out a 15 degree angle about 2 feet up from one end, then cut the small triangle off to make a laminating jig for the shaft.  Then I cut numerous 2" holes along it to hold clamps for when I glued the strips together to make the shaft.  I did my first go through and learned that I needed to add a few more holes and use more clamps, and use more glue between layers.  When in doubt, add more glue because it's easier to glue it then it is to fill in any gaps once the shaft is glued.  I have pictures, but couldn't find the memory card, so you'll just have to visualize this part.  After learning from the first attempt, the second try was much better and was what I ended up using to make the paddle. 
After the shaft was done, I sanded down the sides to make them even and square, then added the sides to the paddle. I had a few strips of lighter wood that I used to create accent strips.  Be sure to clamp them from the side, and also front to back to help the paddle be square when it has dried.  Rubbing any wood you use to guide the process along with paraffin wax.  I made a sandwich with some scrap wood to align the paddle and shaft when I glued them.  Then once the glue was dry, I removed the clamps and the scrap wood and everything was ok.  The next part was marking out the paddle shape and cutting the paddle out.  I used the Sugar Island template from David Gidmark's book on making Canoe Paddles.  Basically there's a grid of x and y measurements, you mark the intersections, then use a French curve to connect the dots.  

Once I'd marked the paddle, I borrowed a friend from church's band saw and cut out the paddle shape.  I marked the paddle on the power face of the paddle to make it easier to cut out, because marking on the back of a bent shaft paddle would make it difficult to cut out with the bend in the wood.
Here's the cut out paddle.  It's rough, but I cut out just outside of the marked lines.  I've learned that with woodworking it's best to be generous in your cuts because you can always take more wood off, but you can't add wood back once it's gone.  Cutting out slightly larger then needed then allowed me to go in with a belt sander and true up the cuts and lines. 
 Here's a close up to the edge of the paddle- note how the cuts are outside of the marked lines! 
I then added a spline to help protect the tip.  Basically a strip of walnut the width of a table saw blade shoved into the gap after I cut down across the end of the paddle.  The spline is about 1/2 inch deep at the deepest and goes across all of the different pieces of wood to help pull them together and keep the paddle from splitting when it's used.  I didn't have a thickness planer, so I spent lots of time with a belt sander making the paddle thinner and lighter, until I had a genius idea and got out my router and made short work of getting it close to the right thickness.  Again, I left it a little thick, then used the sanding to bring it into where I wanted it to be.  I did the same thing with the grip.  I wanted a basic pear type grip so I marked out a pattern with my French curve, then promptly discovered after I was done that there's a pattern in the book I had.  Oh well.  I glued a few blocks of cherry to the top of the shaft for the grips, clamped to dry of course.  Then I sawed and sanded them to the right shape.  I also worked on rounding the shaft.  The book on building canoe paddles mentions a jig with a 7:10:7 ratio to help take the square into an octagon, which can then be further developed into a circle.  I did a little more research on the math behind it and found this site that explains it.  Ingenious!  
After dry sanding until the wood was the shape I wanted and was velvety smooth, I did a last go-over of wet sanding.  Wet sanding helps to get the wood grain to stand up, and makes the final sanding result a polished smoothness that you don't get if you don't do it.  I was ready to varnish my paddle! 
 I got some spar varnish from Lowe's and some cheap foam brushes, then I drove a few nails through some scrap wood to help keep the paddle off of the ground while the varnish dried.  Resting the paddle on the nails was a great way to go.  I brushed on two coats, did some fine sanding with 400 grit sandpaper, then varnished another coat, sanded, then varnished again.  I ended up with 5 coats of varnish, but 4 would have probably been fine. 
 Here's looking down the paddle shaft from the top.  You can see the layers I'd glued together, and also the 15 degree offset to help make the paddle more efficient. 
Here's the final paddle.  It turned out pretty good for a 3rd wood project ever attempted!  It took me about 2 months to complete, but I was pretty sporadic about working on it.  Now I'm ready to go onward and start working on the canoe! 

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