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Archive for August, 2011

One of the most useful tools for beveling the laps  is a bullnose rabbet plane, here a Stanley #90. Unlike a regular plane, the iron of the bullnose rabbet plane goes right out the edge of the sole, so you can keep it right on the pencil line. Its sole also just happens to be close to the same with as the lap bevel on this boat.

At each bulkhead/frame, wood is removed until the straightedge lies flat with its upper edge touching the penciled lap line. You need to be careful not to take off too much, which you can see I’m just on the verge of doing here. The thickness of the bottom edge will depend on the shape of the boat’s hull. Here, the bottom becomes a feather edge. If you do that at each known point, it’s then a relatively simple matter to connect these bevels with a smooth transition. Unless you’re making a boat with flush-lap or guideboat-lap planking, all of the beveling takes place on the lower plank.

We’re back to spiling now. The middle planks will go on in one piece, so the spiling batten goes full length.

The second plank is clamped in place to check for fit. If you’ve done a good job ofspiling, it will just touch the lap line and the marks on each frame/bulkhead showing the lower edge. The next round of fastenings will go in the upper edge of this plank, through the 5/8” lap of the plank below it, and be clenched on the inside of the boat.

In order to do the clench-nailing, we need to clamp the plank in place, but the edge we need to clamp is about 5 ½” away from the lower edge, and most clamps don’t have a deep enough throat to reach. We need lap clamps. These may be for sale somewhere, but everyone I know makes their own. I took a couple of hours one afternoon and made up half a dozen from some scrap cherry left over from the paddle project. They’re hinged at the butt end, sometimes with leather but here with little metal hinges, and the middle is just a carriage bolt with a wing nut. These are a medium size with a 6” throat, but you can alter the pattern to make whatever size you need.

Here are some lap clamps in place on the upper edge of the plank. As well as holding the planks together for clench-nailing, they also let you make a final check of how well your laps are beveled.

A lap clamp in action from underneath the boat.

Before fastening the middle plank, we need to mark out the fastening line.

It’s easiest to do this on the bench, using the same gauge we made to mark the plank laps. The laps are 5/8” wide, and we want the fastenings more or less in the middle, so here we’re marking a line 5/16” in along the upper edge of the plank.

The middle plank is fastened. This time, there are screws in the hood ends at the stem, but all of the other fastenings are clench nails, once again driven from the outside and clenched inside.

2 planks on, one more to go.

Until next time. . .

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At the end of the last post, you’ll remember that had just fitted and fastened one garboard? Well, when we went to trim the rough end of the planking the next day, a split developed near the stem where the plank twists the most. There was already a little split at the scarph, and we started to think that perhaps that plank should come off. As we were looking at it to make the decision, the plank decided for itself, splitting even further. So, off it came, which meant pulling the fastenings, pulling the plank, cleaning off the sealant and plugging the fastening holes with dowels. The twist in the garboard planks from midships to the end meant that there was too much tension in the plank (rule number one: there should always be more tension on the boatbuilder than on the plank!). So, for the next round, we soaked the stem end in boiling water.

The plank was then clamped to the form and allowed to dry. When it was removed, it sprang back a little ways ( probably more than it would have if we had steamed it properly) but retained enough shape that there wasn’t a lot of tension exerted in the final fitting and and the fastenings were holding it in place instead of pulling it into place.

So, once more we fastened the garboard on. This time, we followed the suggestion of the designer and added a couple of drywall screws with washers under their heads from the garboard into the bottom just to hold the plank in close while it was fastened, because it’s not possible to get a clamp in that joint.

With the plank held in place, the fastening holes are marked and drilled with a 1/16” pilot hole.

One at a time, the copper tacks are driven from the outside and clenched inside on the bottom.

The tools of clench-nailing, left to right. A backing dolly. This can be any heavy piece of metal, but I like these panel-beater’s dollies used by auto body shops. They’re nicely curved to fit inside the hull, have a good handle and cost a lot less than the fancy canoe-builder’s clenching irons. Then, a box of 5/8” sharp-pointed cut copper tacks and finally a hammer. A nice small hammer, not a big beastly 16 oz. framing hammer. Clenching requires a series of light, fast strokes to gradually turn and set the nail on the inside of the boat. Oh, and coffee. Can’t build boats without coffee.

While tapping from the outside, the inside hand holds the dolly tight to the point of the nail, gradually turning it into the wood down (towards the bottom of the boat) and across the grain for best holding power.

The 10:1 scarph has been cut in the plank on the bench before it gets fastened in the boat.

The other half of the garboard is overlapped, and the start and finish of the scarph joint are transferred to it. You can also see where the fastenings have been marked out.

The finished scarph. The fastenings are driven from the outside in at the thin end, and the inside out at the thick end. We really should have turned the points of the clench nails more down and across the grain for best holding power. The bottom of the scarph will be faired up before the next plank is fitted.

The other end of the garboard fastened in place, showing the #6 x ¾” screws in the garboard and the #8 x ¾” in the stem.

After fastening, the ends are roughly trimmed to make room for the plank on the other side.

After sawing close to the line, the rough trimming is finished with a spokeshave.

Fitting the second garboard. Where it’s difficult to put a clamp, you can use a “hutchet,” a piece of scrap stock that holds the plank in place.

The second garboard fitted and waiting to be trimmed.

Using the lower edge of the plank as a guide, the laps are marked out. Here, they are 5/8″ wide.

Before beveling the laps, I took a few minutes to trim the edges of the fitted and fastened garboards flush with the bottom.

In order to make the plank edges lie against each other on the lap, the upper edge of the lower plank (once the boat is right side up, that is) needs to be  beveled. There are five places on each side of the boat where you can find out what the bevel should be: at each end, where it tapers to a feather edge; at the two watertight bulkheads and at the midships frame.

Placing a straight edge on the mark showing the edge of the next plank will tell you how much needs to be taken off. What you’re aiming for is to have the straight edge touch the pencil line showing the upper limit of the lap, so as you can see, there’s quite a corner there now to be removed.

Until next time. . .

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At the end of the last post, we were ready to start planking. This is the part where lapstrake canoe construction gets really interesting.

“Spiling” is the process of deriving the shape of a plank from the boat itself. It’s one of those things that you can read about over and over again and not be sure how it works, but as soon as you see it in practice it all becomes clear (sort of like lofting). Fiddlehead‘s designer Harry Bryan has helpfully provided dimensions for plank patterns on the plans, but using those presupposes that we’ve built a framework that’s exactly the same as his. Spiling is a good thing to learn and practice, so we’ve decided to spile for the planks instead. To do this, we need some key pieces of information. When we made the stems, we picked up the heights of the top edges of the three planks on each side of the hull from the plans and marked them on the stems. We also know where the plank edges cross the frame and bulkheads because this boat has those flat faces pre-dressed so there’s a definite point where one plank begins and another ends, and they’re also shown on the plans (on a round-bottomed hull with steam-bent frames,  you would need to “line out” the hull for the planking, but that’s another project).

To pick up the shape of a plank, a 2 1/2″ wide masonite spiling batten is stapled to the bulkheads and frame between the bottom edge of the plank and the marks showing the top edge of the “garboard,” or first plank. The shape of the spiling batten is NOT the shape of the finished plank, but rather a tool to help you derive the shape of the plank.

Using a compass set to a consistent width (here 3”), the point is placed on the edge of the bottom and the pencil end traces an arc on the spiling batten. There will be quite a number of points on the upper edge of the batten (which will define the lower edge of the plank—are you still with me?) but only three points on the bottom edge of the batten at the frame, bulkhead and stem.

The batten is temporarily stapled on to a piece of plank stock large enough to accommodate the full shape of the plank once the measurements have been expanded back from the spiling batten.

Now the marking process is reversed to re-locate the edges of the space the plank will have to fill on the boat. Each arc traced from the boat on to the batten left a partial circle. The compass point is placed where one side of that circle crosses the edge of the batten and an arc is swung on the stock. When the compass point is placed on the other side of the circle where it crosses the batten edge and another arc is swung, their intersection marks the edge of the plank—ain’t geometry wonderful?

If you look closely you should just be able to see the penciled arcs on the batten, along with a notation as to the width of the compass.

A finishing nail is driven in at each intersection, and a batten is sprung.

Here you can see the spiling batten and the shape of the right-hand edge of the plank, which is (hopefully!) the shape of the space on the boat that the finished plank will occupy.

Here the other edge of the plank has been de-spiled (yes, that’s a word, a least in the boat shop) and a second batten sprung to show the other edge of the plank.

Once everything looks fair, the battens are held down and traced to show the final shape of the plank.

The rough-cut plank is clamped in place to test for fit.

Quick-clamps with large, rubber heads are perfect for working with the soft cedar planking. They can also be opened and closed with one hand, which is a great help to the solo boatbuilder.

A bow view shows the significant twist in a garboard plank, which must make a transition from nearly horizontal in the middle of the boat to nearly vertical at the stem. The white cedar planking is limber enough to make this twist without steaming, but only just, and needs to be handled carefully at the stem.

With the plank clamped temporarily in place you can check to see how good a job you did with the rolling bevel and tune it up where necessary.

The excess planking is trimmed off about 1” beyond the stem.

These garboard planks will be scarphed together near the middle of the boat. Measuring back 2 ½” from the end of the plank will give a 10:1 scarph joint, which can be cut with a good sharp chisel.

The scarph can also be cut with a low-angle block plane. This is the kind of work which will quickly let you know whether your tools are sharp enough or not.

This boat is truly double ended, so the first plank can be traced and cut out to make the second, and then if you do it twice more you’ll have the planks cut for the other side, too.

As always, bandsaw a little outside the line (“leave the line!” the old craftsmen say) and then dress right down to it with a sharp block plane.

There are many nice features of a low-angle block plane, one of them being that it’s light enough to hold in one hand, so you can either push it away from you or pull it towards you, depending on which way the grain wants you to go.

Here’s the scarph joint being fitted on the boat. Traditionally the scarph faces aft on the boat, but since you don’t decide which end of the Fiddlehead is the bow until you put the backrest in, we’ll just make them all face the same way.

The first pair of planks dry-fitted and ready for fastening.

Garboards are the trickiest planks to fit, so a couple of friends dropped by to help. Beth Stanley and Jeremy Ward both work at the Canoe Museum.

Between the stem and the bulkhead, the garboards are fastened to the bottom with #6 x ¾” screws. The holes are drilled and countersunk first, and the screw heads will finish just below the surface so the holes can be puttied later. Beyond the bulkhead, the garboard is clench-nailed to the bottom. At the scarph joint, half of the tacks go from the outside in, and the other half go from the inside out, which means you get to hammer blind, but it’s not as hard as it sounds. 5 more planks to go!

Until next time. . .

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I’ve always been intrigued by old things–I guess that’s what led me to the museum business where I make my living. What is it about old things that interests me? It’s partly the challenge of understanding them, of coming to learn why that object looks the way it does, and how it w0rks, and what we can learn from the object about the knowledge embodied in it.

When you consider an object from a time when more things were built (made one at a time, or in small batches, often by their users) than manufactured (made in great quantities by someone other than the user), there’s often a great deal of character embodied in them. You can understand some of that character by using one of these objects, but you can learn even more by making it and then using it. This is what has led me to build some old/new boats, to rehabilitate some old boats, and lately to carve what I’ll call a new (old) canoe paddle.

I’m not 100% sure what to call this paddle–“replica” sounds too exacting, claiming a precision that I don’t have. “Reproduction” sounds banal, as in “only a reproduction.” It is just a canoe paddle, but it’s also more than a canoe paddle in that it’s the product of a deliberate reaching back to an earlier era in a search for a design and a style. I rather like the phrase “spirit of tradition” which some of the classic yacht people coined to describe, say, a new build of a Herreshoff schooner that wasn’t a complete copy in terms of materials and techniques but was nonetheless built to the original design and embodied some of its character.

Sometimes these spirit of tradition projects of mine are prompted by the experience of using something old. In the case of the St. Lawrence Skiff I built a number of years ago, I had a chance to row an original one and decided right then and there that I had to build one for myself. I’m rowing the original on the left, and the owner of the original is rowing my new skiff on the right.

In other cases, just seeing an original item makes me want to build one. Earlier this year, staff of the Canadian Canoe Museum were looking through the workshop of Walter Walker. Walker, who passed away in 2009, was a near-legendary canoe builder in the Peterborough/Lakefield area who, over the course of a long career, had worked for just about every canoe company in town, and also for quite a while on his own. As well as building canoes, Walker carved paddles, and he had a favourite shape that featured small shoulders at the top of the blade and the bottom of the grip. In Walker’s workshop there was a late 19th century pattern from the Lakefield Canoe Company that his stepson says was the basis for his own favourite paddles:

Here’s a closeup of the grip on the pattern:

And the top of the blade:

Walker’s workshop also yielded another interesting piece in the form of an old, weathered paddle with a big split in its blade. Though well past its prime, this was a quality piece of work. Carved from birdseye maple, it too had shoulders at the top of the blade and the grip, but was altogether more delicate in its scantlings. The shaft was distinctly oval, especially at the top of the blade where your lower hand would grip it. The story goes that this paddle, dating from the end of the 19th century, had been given to Walker by someone in Burleigh Falls, north of Peterborough. He appears to have made some of this shape for himself, for there were masonite patterns in his workshop. This one really caught my attention, so I traced off a pattern, took it home and found a suitable piece of cherry.

Several months and a car accident later, I’ve carved one for myself. The only changes I made were to add a few inches to the shaft, but leaving the blade length unchanged, to make it the right length for me to to draw out and square up some details on the original that seemed to have been worn down over the years. Although I took a 2-D pattern tracing, I didn’t make any other measurements or templates to use when I carved it. I wanted to see how close I could come to the shape of the original working just from the pattern and  my initial impression of it.

It was an interesting piece to carve. Several times I felt like I’d gone too far, and taken off too much, especially where the shaft meets the bottom of the grip, but when I compared the old and the new I felt like I’d gotten it just about right (except that looking at this photo now, I can see that the “horns” at the bottom of the grip are a little asymmetrical–funny that I never noticed that until now).

And what is it like to use? A real treat. It’s light, subtle and just a little whippy in the water, perfect for an evening solo paddle. As pleasant as it is in and of itself, though, for me the enjoyment is greatly increased by its being a new (old) thing. I just might have to make another one.

PS: Until April 2012, you can get a first-hand look at Walter Walker’s canoes, tools and workshop, and learn more about his long career as a canoe builder, in the CCM’s exhibit “Walter Walker: A Life in Canoes.”

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With the bottom shaped, it’s time to get everything we’ve built so far set up on the strongback.

The plans show a baseline above the midships frame and the bulkheads that represents the top of the strongback. Using this, temporary legs are cut from scrap and fastened with drywall screws. The frame and bulkheads are plumbed and aligned on the strongback and the legs are fastened to cross-cleats.

The stems are fastened to the bottom with screws and glue.

The bottom/stem assembly is placed on the frame and bulkheads and carefully aligned. The bottom is then glued and screwed to the frames and bulkheads.

The stemheads are extra long, extending beyond the sheerline. When the boat is turned upright, these will each be trimmed and shaped into a pleasing curve. In the mean time, the height of the stem and the height of the legs on the frame and bulkheads affects the curvature, or rocker, of the bottom. When the bottom is fastened to the frames and bulkheads and the stems are pulled down tight to the strongback, it introduces a (very slight, for this particular boat has almost no rocker) curvature.

At the moment, the edges of the bottom are square, just as they came from the bandsaw. The bulkheads and the frame, however, are angled so the planks must meet the bottom at an angle and the bottom must therefore be bevelled. How do you find the correct angle? By playing “connect the dots,” or rather “connect the bevels.” Where a bulkhead meets the bottom, you can lay a straight piece of scrap along it and see how much wood must be planed off to make the scrap lie flat.

If you do this at each intersection, and also where the stems meet the bottom, you will have four known points on each side to guide you. The bevel “rolls,” or changes between each of these, so your job is to join these areas up with a fair curve to create this rolling bevel.

Here are four of the most useful tools for doing this kind of work, and in fact four of the most useful tools in a shop that builds traditional small boats. From left to right, they are: a jack plane; a low-angle block plane; a bullnose rabbet plane and a low-angle spokeshave. In the backgound is an awl, useful for clearing chips and shavings from the throats of the tools.

The next pieces to be added are the sheer clamps, which define the upper edge of the hull. These are important elements that join the sheer plank, decks and stems together, so they’ll be gotten out of white oak. I couldn’t find any stock long enough, so I ripped a shorter piece of white oak and scarphed it together with epoxy, using an 8:1 angle.

Ripping this long, flexible piece takes careful preparation, so I’ve made some temporary supports to hold before and after it passes over the saw. As usual, the preparation takes about 5 times longer than it does to make the actual cut. Once the sheer clamps are ripped, they are planed to the final dimensions.

The clamps fit into pre-cut notches in the bulkheads and frames. At each stem, they must be cut so that the planking will flow smoothly off them and on to the stem bevel. This is pretty easy at one end, using a bevel gauge to lift the correct angle and cut the end of the clamp. At the other end, though, the untrimmed end will be in the way of an exact measurement, so it requires some careful thought to cut the correct angle at the correct length.

With the bevels cut in each end, the sheer clamps are screwed to the frame, bulkheads and stems.

Everything is now in place for planking, where we’ll pick up next time.

Until then. . .

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We’re doing a construction diary of Harry Bryan’s double-paddle canoe Fiddlehead. In the last post, we were laying out the shape of the bottom, so let’s pick up from there.

A finishing nail is driven in at each point, and then a flexible batten is held against it with other nails to make  a smooth curve. This leaves a few small holes, but they tend to disappear as the project goes on.

It’s tough being fair in both life and boatbuilding. Before the curve is drawn, it’s important to sight down it and make sure that it’s “fair,” without humps or hollows or flat spots. The longer your view of the curve, and the lower the angle you view it from, the easier it is to spot unfairness. If you see a spot that looks flat or hooked, pulling the nail and watching the batten move will tell you if you have a problem. Sometimes I nail a line and go for a walk before drawing it.

The fair curves of the bottom are bandsawed just outside the pencil lines.

The sides of the bottom are then dressed down to the pencil lines with a block plane.

The shape of the watertight bulkhead is transferred from the plan to masonite to make a pattern.

The bulkheads are made up of two diagonally-opposed layers of ¼” cedar glued together with epoxy. Cut from random widths of cedar, they make economical use of scraps from the bottom planks.

A completed bulkhead with the pattern. The circular hole in the middle will have a screw-in watertight hatch.

Since we’ll be building this boat with classes, I’ve made masonite patterns for all of the smaller parts, including the midships frame, the stems and the coaming brace. These were made the same way as the bulkhead pattern, by pricking through the plan and then joining the points with pencil lines.

Finished spruce pieces for the stems and the midships frame.

Transferring the curved line showing the start of the stem from the pattern to the stem.

To be continued. . .

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The Canadian Canoe Museum in Peterborough, Ontario is setting up a new workshop and teaching space called the Living Tradition Workshop. Created in honour of Walter Walker, the eminent Lakefield Ontario builder of wooden canoes (primarily in the longitudinal strip technique) who passed away two years ago at 101, the new space will be used to share the techniques of canoe building, repair and restoration with museum visitors. It should be open by early fall this year.

The museum has a long history and quite a bit of expertise in dealing with birchbark, wood-canvas and longitudinal strip canoes. Until now, however, they haven’t had a chance to spend much time with the kind of lightweight lapstrake construction that was one of the main techniques of recreational canoe building in the later years of the 19th century. What better way to inaugurate the new workshop than to build a little lapstrake canoe?

The canoe I chose for this project is called Fiddlehead, and was designed by Harry Bryan. Harry is a frequent contributor to WoodenBoat and has a fine eye for a sheerline and a traditional hull. He also has a unique design philosophy, and his website is replete with beautiful small boats with a minimal environmental footprint.

 Fiddlehead is a flat-bottomed version of the kind of small double-paddle canoe popularized by John MacGregor and his Rob Roy designs in the early years of recreational canoeing by way of J.H. Rushton’s famous Wee Lassie.She can can be built in three sizes, but I’ve chosen the smallest, 10 1/2′ overall, because it will work best for classes where we’re building multiple boats and has all the features of lapstrake construction in a nice compact package. Here’s what she’ll look like when she’s done. That’s Harry himself at the helm.

The museum’s new workshop is still under construction, so I’ve started the canoe in my shop at home to get the project rolling. Here’s the first part of a Fiddlehead construction diary.

Every project begins with careful study of the plans and instructions.

The bottom is made from three white cedar planks, edge-glued together with epoxy.

Once the bottom planks are glued together, the squeezed-out glue is planed off and the bottom is sanded. And now the usual disclaimers about safe shop practices. 1) Yes, I do have bare feet; 2) no, I don’t normally do that in the workshop, but when you’re taking pictures of yourself with the self-timer and not really working but only pretending to work, that’s what sometimes happens; 3)I also don’t normally wear safety glasses when using a low-angle block plane (notwithstanding what the product liability lawyers might have recommended) but in this case I have reading lenses in my safety glasses so I don’t beat up my good glasses in the shop.

The width of the bottom at certain stations is transferred from the plans (see, I have my steel-toed safety Birkenstocks on in this photo!)

To be continued. . .

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