TECH TIPS PAGE NINETEEN
News and Stuff
Building Tip - More on Miniatures by Ted Behne
Making Thwarts and Installing Them
Previous articles outlined the process for selecting a canoe to model, reducing its dimensions to one-quarter scale, making a "blueprint" of the canoe, constructing a reusable building platform and making a gunwale frame. To review previous articles, go to "Tips" and sort through past issues of "The Bark Canoe Aficianado."
Future articles will focus on making the component parts of the canoe; gunwales, gunwale frame, thwarts, ribs, sheathing, etc. Preparing these skeletal elements constitutes at least 50 percent of the work of building any canoe. Each part can be made separately, at any time and in any sequence, then stored until you are ready for assembly. It should also be noted that all of these procedures are identical to those for making full size canoes. Required tools: X-acto razor knife, coping saw, short-blade carver's knife, 1/32" drill bit.
Determine the shape and dimensions of each thwart from the ¼-scale blueprint of the canoe you have selected to build. Thwart styles vary considerably with different tribal styles and different builders. In some styles thwarts are like boards, completely lacking elegance. In other styles they are graceful and shapely. It is one of the areas of canoe building in which builders can display artistry and individuality. Of course, thwarts are also functional and must be strong enough to serve, along with the gunwales, as the backbone of the canoe. Hardwoods such as Ash, Maple, Oak or Birch are often chosen for their strength, but some builders also use Spruce or even Cedar. Draw a centerline on each thwart blank to use as a reference during shaping. Do the rough shaping with a coping saw, then the final shaping with a short-bladed carver's knife, leaving the tips that extend through the gunwales unfinished. When you are ready to assemble the gunwale frame, form tenons at the ends of the thwarts, leaving "shoulders" at the inboard edges of the inwales.
Installing Thwarts in the Inwale Frame
After the inwale frame has dried thoroughly, mark the locations to cut mortises into each inwale, using the thwart tenons as templates. Then disassemble the inwale frame to gain best access to the mortise locations. Use the pointed blade of an X-acto knife to cut thin mortise slits through the sides of the inwales. To retain maximum possible strength in the finished inwale frame, make the mortises and the tenons as thin as possible, consistent with adequate strength. The final fit for each mortise and tenon should be snug.
Reassemble the inwale frame, holding the thwarts in place temporarily with rubber bands or string. As you do this, say a little prayer that the inwales don't break as they bend at each of the thwart mortises. If the inwale frame remains intact, tempt fate even further by drilling a 1/32" hole vertically through the inwales and each thwart tenon. Peg each hole with ½ of a round toothpick, tapped into place until it is tight. The hard wood of the toothpick will spread the sides of the soft cedar hole and lock the peg in place as though it were a nail. Carefully trim the top and bottom of each peg so as to be flush with the inwale surfaces. Tie the ends of the inwales together with sturdy sewing thread. Color doesn't matter, as the ends of the inwale frame will be hidden in the finished canoe.
The inwale frame is now complete and can be set aside while other components are made. Next, turn your attention to making ribs, the essential skeletal elements of the canoe. That process will be described in next month's newsletter.
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