Friday, April 24, 2009

A New Method?

One of my fellow woodworking students in the furniture making class that I take is also a paddler. She made a pair of Greenland paddles for both herself and her husband and would like to make a wooden boat, but is sensitive to the cedar we use to build canoes. We've been working to figure out a way for her to build a boat, but not use cedar.

Another thing I've been looking at is how I can offer other classes. One concern that I have is that it takes a long period of time and a some skill to build a cedar-strip canoe. I've been looking for a project that will be a bit less intensive and a bit less costly. I'm still looking to have the students build a light-weight, easy to handle boat, and skin-on-frame kayaks look like a decent option. Still, these types of kayaks can be relatively complex to build.

What I've found is Thomas Yost's website. Most of the boats that he builds are based on Greenland style and Aleut style kayaks. He covers folding aluminum and plastic frame kayaks, wood-framed non-folding kayaks and inflatable kayaks. In particular, I'm interested in his simplified non-folding wood framed boats. Here are a few pictures of his work - I particularly like the clear PVC skin because it shows the framing technique very nicely.

I'm not enthusiastic about three things which are part of his method:
  • Use of relatively expensive cedar (Which my friend is sensitive to...)
  • Use of PVC skinning materials and solvent cements
  • Lack of paddler "customization"
I've been reading a few other books on skin-on-frame boats by Starr, Cunningham and Morris. What I like about what I've seen in these books is the use of white pine for the major stringers. It's strong, light and low cost and most people aren't sensitive to it. It isn't very rot resistant, but these boats aren't left exposed to water for long periods of time and the wood of the frame can be coated with waterproof finishes.

These books also suggest the use of ballistic nylon (or dacron materials) very much like George Dyson does with his kayaks. I think that this looks like a better method than the PVC as it should be lighter, look more like a traditional skin and has fewer seams - one down the center of the deck. I also like the idea that I can use water-based polyurethane finishes to cover the nylon as opposed to noxious solvent based PVC adhesives. They also seem to be tighter skins than the PVC.

Last but not least is the customization for the paddler. Scale and balance in small canoes and kayaks is critical to the paddler. It is important that the boat 'fits' the user. While Thomas Yost offers some interesting designs, they're generic and may or may not fit the user. My hope is to incorporate the framing style and use of plywood cross-sections, but to offer a way to customize the size of the cross sections to the user.

Ultimately I'd like to be building and teaching more traditional skin-on-frame kayaks like the one shown below from Robert Morris' Brewery Creek Small Boat Shop. For now, I'm going to be satisfied with getting my friend on the water in a boat of her own manufacture.

I'm planning to start the process with a small model (1/3 scale) of one of Yost's 15' boats - the Sea Tour 15R - to get a good start on the build process. I'll be adding more posts on the subject as I progress.

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