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Paddling Articles In the Same Boat

The Practical Paddler

Pattern-Making with a Jogglestick

By Tamia Nelson
tamia@paddling.net

December 31, 2002

There's nothing like the end of the old year, with its ritual summing-up and crystal-ball gazing, to remind us that ours is indeed an age of wonders. And these wonders aren't limited to labs and offices. They're as near as your toolbox. Want to measure a room in your house? No need to wrestle with a clumsy steel tape. Just grab your electronic tape measure, point it at a wall, and press the magic button. The digital readout will tell you all you need to know.

Sometimes, however, the old-fashioned tools are best. Suppose you want to fit a bulkhead to your kayak, or build a custom, form-fitting wannigan for your canoe. How are you going to make the pattern? It isn't easy. You can eyeball the job and cut a template out of cardboard, of course, but unless your eye's better than mine, you'll have to do a lot of trimming before you have a good fit.

Is there a better way? Sure! Let's take a look in the toolbox of a nineteenth-century shipfitter. You'll probably see a gadget that looks like a pumped-up, coarse-toothed, wooden saber-saw blade. It's a "jogglestick"— sometimes called a "pattern stick"—and it's nothing more than a pointed wooden batten about 1½" x 24" overall, with deep (c. 1"), asymmetrical teeth cut along one edge. Jogglesticks are easy to make. A thin (c. ¼") piece of hard oak's probably the best material, but a softwood furring strip will work in a pinch. You don't want anything that's too flexible, though. Once you've cut your teeth—it's not as painful as it sounds!—number them on both sides of the stick with a laundry marker or black enamel, beginning at the point. You'll probably want to leave 6" or so uncut as a handgrip, but that's the only fussy bit. The teeth don't even have to be the same size or shape.

Not exactly high-tech, eh? A jogglestick needs no batteries, and there's not a single moving part. So how's it work? Easy. Suppose you want to make a pattern that exactly reproduces the cross-section profile of your canoe at a given point. Just clamp a rectangular piece of plywood scrap (1½' x 1' would be about right, though the dimensions usually aren't critical) to a thwart near the place where you want to strike the inside arc. This is your "tally board." Be sure that it's rigidly clamped, and that it's both (1) vertical and (2) perpendicular to your canoe's keel line. (NB If there's no thwart handy where you want to strike a line, or if the thwart's curvature makes it hard to fix your tally board in place, improvise a temporary thwart with a length of 2 x 4, clamping it to the gunwale of your boat. Just be sure it's clamped square.)

Now take your jogglestick and hold it so that it lies flat against the face of the tally board. Put the pointed tip against the bilge or the side of your canoe, and trace the outline of the jogglestick on the tally board with a sharp pencil, being careful to hold the stick in place. When you're done, write the number of each tooth on the tracing. (You only need to identify one tooth, but a little redundancy never hurt, did it?) Then repeat the process until you've mapped the inside of your boat from gunwale to gunwale.

Mapping the Curve

Next, remove the tally board and clamp it to the plywood sheet or piece of cardboard that you'll be using to make your pattern. Fit the jogglestick in the pencilled outlines on the tally board, one by one, matching tooth for tooth and marking where the point of the stick falls on the pattern. Keep going until you've plotted every point.

Plotting the Points

Lastly, when you've finished plotting all the points, just connect the dots with smooth curves. You'll have a pretty near exact pattern of the inside cross-section of your boat at the location where you clamped your tally board.

Connecting the Dots

It couldn't be easier, could it? But there are still a few things that you should know.

The Finer Points of Joggling

  • If you're making a custom wannigan for your canoe, be sure to allow an inch or two of clearance at the inwales. You want to be able to get your new wannigan in and out of your boat, after all! And don't forget to take the boat's taper into account, too. If you've never done this sort of work before, it's probably best to use cardboard rather than plywood for your first pattern, and then check it to be sure everything's OK. It's easier—and cheaper—to correct mistakes before you start cutting costly materials.

  • Whatever you're making, it's always simpler to take stuff off than put it on. So it's good to err on the side of generosity when you cut your final panels. You can easily take down any high spots with a sharp plane, Surform® tool, crooked-knife, or sandpaper.

  • In a hurry? Who isn't! That being the case, you may be tempted to do just half the job—lay out a half-pattern—and then reflect it around the vertical axis. After all, your canoe's symmetrical. Or is it? Oddly enough, even mass-produced boats popped out of molds are sometimes lopsided. Not by much, of course. Not enough to noticeably affect stability, tracking, or handling. But enough to mar the fit of a custom wannigan or bulkhead. The moral of the story? It's easier to do a job right in the first place than to redo work you've botched. Take your time and make a complete pattern.

  • If you plan to use a jogglestick to fit a bulkhead in a kayak or other decked boat, or anyplace else where space is tight, you'll need ingenuity and very long arms—not to mention a custom-sized mini-jogglestick. There's a better way, however. Make a profile of your boat's outside curve. Just remember that you'll need to hold both boat and tally board firmly in place, and don't forget to allow for the thickness of the hull when you cut the final pattern!

No, it's not state of the art. But it works. And that's the important thing, isn't it? The jogglestick on your basement workbench has come a long way from the naval dockyards of the eighteenth and nineteenth centuries. It's still ready and willing to do a good day's work, though. Give it a try the next time you need to make a pattern and see if you don't agree.

Copyright 2002 by Verloren Hoop Productions. All rights reserved.







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