Friday, January 23, 2009

Spare Forms

As you know from some of my previous posts, I took Jerry Stelmok's cedar and canvas canoe building class at the WoodenBoat School this past summer. One of the reasons that I took the class is that while I've done a fair amount of restoration and re-canvasing work on canoes, I've never done this type of boat from "scratch". I've worked on two B.N. Morris Canoes, one Chestnut, a Grand Laker, and two Old Town boats and found it to be quite absorbing.

To be honest, I enjoyed it very much. First, we worked mostly with Eastern White Cedar which works a bit like Styrofoam compared with Western Red Cedar. Western Red Cedar is the wood we commonly use for strip building and is a very brittle wood. The Eastern White Cedar isn't brittle and machines very easily. The other thing about this type of construction is that there are no adhesives to speak of used in the process. Very often during the build of a Cedar strip canoe, my students find themselves feeling like an ant in a syrup jar as they seem to wind up coated with glue and epoxy during both the stripping the fiberglassing processes.

One of the major impediments to building this style of canoe is the construction and storage of a form over which you build the canoe. They are large and heavy. The build of a complete form for a cedar and canvas canoe takes as much or more time as building the boat itself. Once constructed, you need a place to store the canoe form.

During Jerry's class, we discussed a method used by another builder and WoodenBoat instructor, Alex Comb. Alex is the proprieter of the Stewart River Boatworks. Alex has developed a method for building a cedar and canvas canoe over what can best be described as a "spare" form. It has a strongback and plywood cross-sections of the hull similar to those used for Cedar-strip construction. The difference is that the forms are small to allow for the thickness of some longitudinal stringers (attached to the cross-sectional patterns with zip ties), the mounting of the inwale and stems. Jerry had concerns about the ribs being faceted as they were bent over the stringers. He seemed to have missed one small detail. Alex uses either a piece of plastic or metal to support each rib as he bends them over the stringers and then attaches them to the inwale using a bronze ring-shank nail. Once all the ribs are installed and faired, the stringers are removed and the hull is planked. The only difference between Alex's method and traditional construction is that there are no metal bands to clench the tacks - this must be done with a clenching iron.

Another relatively non-traditional method that Alex uses is Dacron as a hull covering. I still have some questions and misgivings about this, but it looks interesting as well.

There are two articles that Alex published in the WCHA's magazine, Wooden Canoe about both subjects on his "classes" page. Here are the links to "One-Off Wood and Canvas Canoe Construction" and "Dacron for Wood and Canvas Canoes" from his website.

I find this a particularly interesting set of methods as it would allow me to teach a class in wood and canvas canoe construction at the school where I work. My students cannot store their canoes in the shop during the week as the shop is used for other woodworking classes and we have to move the canoes back and forth between the shop and a barn that is on the site. A "spare" form would be light enough to move back and forth in this manner and would allow for me to teach other classes at this school. The other interesting point is that the construction method uses slightly thinner ribs and the Dacron to produce a lighter weight canoe.

I think a little research is warranted!

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