TECH TIPS PAGE TWENTY

Building Tip - More on Miniatures by Ted Behne
Making Ribs

This article will outline the process for laying out and making ribs. 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, making a gunwale frame, making and installing thwarts and splitting cedar. Future articles will focus on assembling the components of the canoe: the gunwales, gunwale frame, thwarts, ribs, sheathing, etc. Preparing these skeletal elements constitutes at least 50 percent of the work of building any canoe. The assembly process takes the other 50 percent of the building time. Each component of the canoe 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 the procedures outlined in these articles are identical to those for making full size canoes. Required tools for making ribs: X-acto razor knife, metal straight edge, low-angle block plane.

Begin by studying the "blueprint" to calculate the number, placement and spacing of the ribs. Rib widths, shapes and spacing vary greatly in various tribal styles. Some are very narrow and widely spaced, like the Northern Cree, while others literally seem to "panel" the interior of the canoe, like the Maliseet. To simplify the rib layout process make a layout stick(s) marked with the lashing and rib locations between each thwart. Ribs should be located on both sides of thwarts but not under them. Notch the underside of the layout stick(s) to fit between thwarts, but allow the topside to extend over the thwarts. Transfer the lashing and rib location markings on the stick(s) to the gunwales with a pencil. Mark the lashing locations with an "X" to distinguish them from the rib locations. The "X" will be concealed under the lashings in the finished canoe.

Ribs should be made in three lengths, the shortest to be fitted from the stems to the end thwarts, the next longest from the end thwarts to the quarter thwarts, and the longest from the quarter thwarts to the center thwart. Determine the appropriate lengths by laying a flexible measuring tape on the blueprint cross-section and measuring the lengths needed in each case. Count the number of ribs needed in each length, add a few extra for breakage when bending, then add up the total to be sure you have enough to do the job.

Rib widths vary considerably among tribal styles. Typical full-size width for a Maliseet canoe rib, for example, is 2 ½ to 3", which becomes 5/8" to ¾" at one-quarter scale. Rib thickness is 3/8" for a full-size canoe in virtually all styles. The 1/4-scale size is 3/32". That may seem tiny and impossible to replicate accurately, but after you make a few you may be surprised at how easy it is "eyeball" the correct thickness and to efficiently repeat it. Most rib styles are tapered, with the taper confined to 25 percent of the rib at each end. Make a perfect pattern rib for each of the three lengths and use it as a template to make others. Use a razor knife to cut out the rib blanks. Use a low-angle block plane to form the tapers and to round the top edges of each rib.

Bundle the finished ribs by size and set aside to wait for bending. Next, turn your attention to preparing roots for lashing the canoe together. That process will be described in next month's newsletter.