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Posts Tagged ‘canoe building’

Shopping for a New Shop

Posted in Boat Building, Boats, Uncategorized, Workshop, tagged boat building, canoe building on March 30, 2014| 2 Comments »

If you’ve been following this blog for a bit, you’ll probably have seen photos of the shop I built in the basement of our house in Peterborough, Ontario. It’s been a great place to work, with just enough space for the kind of small boats I like to build and restore.

On their way in or out, the boats leave through the window (though I did once bring a 17′ canoe down in the front door, through the living room and down the stairs just to prove that it could be done). Here’s the planked-up Fiddlehead on her way out to be finished at the Canadian Canoe Museum.

If you’ve noticed that the blog has gone kind of quiet lately it’s because of some major life changes that have taken place over the last few months. I had just gotten the Ontario Canoe Company decked sailing canoe set up in the shop and was starting to think about restoration when a new writing project came my way in the form of a commission from WoodenBoat, who wanted a feature article on Harold and Lorna Wilson and their Miss Canada racing powerboats for early in the new year. I was already working on the research for a new exhibit for the Canadian Canoe Museum on the subject of canoes and romance, about which I had been collecting ephemera for some time, and I was also going to write a museum Gallery Guide to accompany it. With those projects in hand, and the restoration pending, I was feeling comfortably well-supplied with things to do.

Then, I decided it was time to take a big step. After more than five years as the General Manager of the Canadian Canoe Museum, I was thinking that it was time to get back to the kind of work that got me into the museum business (research, writing, designing and building exhibits, working with artifacts) instead of the kind of work that General Managers do (board meetings, budgets, marketing, staffing and volunteers). When an opportunity presented itself at a museum just west of Toronto, I seized it, and in January of 2014 I started a new job as the Curator of the Halton Region Museum.

So far, so good, and everybody is happy now, except that we’re into the “M” word: “MOVING.” I’ve always believed that “good move” is an oxymoron most of the time, but that hasn’t stopped us from making a few of them. As we looked at new houses, I was hoping to finding something like our place in Peterborough, with an unfinished basement and a decent-sized window. Late in December, we closed on a beautiful new townhouse with just that. So, here’s a pre-project photo of the space where the new shop will go.

Most of what I’ve done since New Year’s is just think about this, as opposed to cutting lumber, since the article and the gallery guide took precedence. However, the article’s now done, the gallery guide is at the printer’s, the exhibit opens at the end of April and it’s time to think about the new shop. Here’s the plan so far. Please forgive the rather ugly canoe shape–it’s not pretty, but at least it’s the right length and width. As you can see, I’m aiming for tight but functional, since the basement also has to accommodate my office and a laundry room/storage area.

First step is to get the sub-floor down, and I’m just about to start that. The Ontario Canoe Company canoe is still first in line for restoration, but there’s a workshop to build first!

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Ah, Tradition!

Posted in Boat Building, Boat Restoration, Canoe Restoration, Canoes, Uncategorized, tagged boat building, boatbuilding philosophy, boating history, canoe building, canoe history, canoe repair, lapstrake construction, traditional boatbuilding, traditional canoebuilding on October 14, 2013| 1 Comment »

In response to a post at the end of July about re-canvassing the 1937 Old Town, reader David Little posted an interesting comment in response to my use of epoxy as a canvas filler:

I understand the need to make things last longer…although it seems the previous traditional filler and paint lasted pretty long considering it was put on over 70 years ago….i do not subscribe however to taking the tradition out of traditional…i would not have gone to modern methods as a filler…the synthetic somehow doesn’t sit well with my view of tradition…just my thoughts.

His thoughts prompted some thoughts of my own, beginning with the words of a true expert on the subject.

As the film opens, Tevye says: “Traditions, traditions. Without our traditions, our lives would be as shaky as… as… as a fiddler on the roof!” (boat builders and restorers might take some ironic pleasure in the other song the film made famous: “If I was a Rich Man. . .”) But what is tradition, and by association, what is traditional?

At a fairly fine and granular level, tradition means simply keeping things exactly like they were. In the context of boatbuilding, this might mean that a steam-bent rib of white oak should always and only be made from white oak. At a mechanical level, traditions can be founded on properties. The oak rib, for instance, is such because oak happens to be an excellent material from which to bend ribs. But, it isn’t the only one, so one also sees small boats with ribs made of ash, elm and cedar, among other woods, because they share the same mechanical properties. Substituting one of these woods for another might therefore be “un-traditional,” but it may not necessarily change the fundamental character of the boat, because the steam-bent rib is still doing what has always done.

However, if you were to make a change in the structure of that rib, you’re dealing with tradition in a different way. Let’s say that your steam-bent oak rib becomes a laminated epoxy oak rib. Now you’ve introduced a significant change and, I would suggest, broken from tradition, because the rigidity and strength of the epoxy change the properties of the rib. The outward similarity–someone looking at the boat would still see a thin bent rib–masks a significant change. In the same way, a glued-lapstrake plywood boat is still lapstrake, and therefore nominally traditional, but whatever the outward similarity, it is a fundamentally different structure with different mechanical properties whose component parts have a different working relationship than in a traditional lapstrake boat.

To me, one test to apply would be the Arts & Craft movement’s maxim “Truth to Materials.” If the component parts of a boat still bear the same mechanical relationship to each other as they did in the original, then, possibly with minor variations, the boat might be said to be traditional. That is, a lapstrake dinghy built with clench nails and rivets and steam-bent frames in North America is traditional with respect to the same dinghy built in the UK, notwithstanding that when the builder moved across the pond he found out that he couldn’t get the larch stock he was used to for planking so he substituted oak.

Thus, with all due respect to American Traders, who build this canoe, this is not traditional:

What started life as a wood/canvas canoe, where a non-water tight wooden shell supported a layer of waterproofed canvas stretched tightly around it, is now a different kind of watercraft, where resin-impregnated fiberglass cloth not only keeps the wood water tight but is also mechanically and chemically bonded to it. Before the mail starts coming in, I’m not saying it’s not a good canoe, just that for all of its outward similarities to wood/canvas canoes it is a fundamentally different structure.

This, by comparison, is traditional, at least to my way of thinking:

Yes, the canvas has been filled with epoxy, and not a mixture of silica, linseed oil and white lead. However, 1) it’s still cotton canvas; 2) it’s still not fastened to the hull except by tacks at the ends and gunwales; and 3) it still comes off in a couple of big pieces when it’s time to re-canvas.

Interesting topic to ponder. What do you think?

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Re-Canvassing a 1937 Old Town Canoe, Part 3

Posted in Canoe Restoration, Uncategorized, tagged canoe building, canoe repair, Old Town Canoe, re-canvassing on July 28, 2013| 1 Comment »

Once the canvas has been stretched on to the canoe hull, it needs to be filled. This fills the weave and waterproofs the exterior, making a smooth surface for the final coats of paint. To say that there’s lots of different canvas-filling options out there, and opinions to go along with them, is a bit of an understatement. Traditional oil-based fillers can be obtained from The Buckhorn Canoe Company in Canada and Island Falls Canoe in the US, among others. The good folks at the Wooden Canoe Heritage Association have collected a whole bunch of recipes for various fillers if you’d like to try mixing your own. Mike Elliot, who writes the Canoeguy’s Blog in British Columbia, now uses a latex pipe-lagging compound, and there’s probably more possibilities still waiting to be discovered.

I’ve used traditional linseed oil and silica fillers before, but this time I thought I would try something new. Dick Persson at the Buckhorn Canoe Company has been experimenting with using epoxy as a filler for wood-canvas canoes. It’s readily available, dries fast and is durable. So, I took Clementine up to his shop one Saturday morning.

This job was done with WEST system, but there’s no reason why it wouldn’t work just as well with any other epoxy product. You’ll need resin, hardener and a lightweight micro-balloon fairing compound, in this case WEST 410.

The first coat is un-thickened resin, poured on and distributed with a squeegee. The goal is to work it into the canvas and distribute it evenly but not leave excess on the surface. One difference that Dick has found with epoxy over conventional fillers is that you shouldn’t scorch the nap off the canvas first, since this hardens the surface and prevents the epoxy from penetrating through. Remember too that this filling method is being used on a hull whose outer surface has received several coats of varnish and mould-release to prevent it sticking.

We went from one end of the canoe to the other, pouring it on, working it in and then scraping off the excess. At the end of the first coat, we went back and hot-coated a second layer. This is a job for old clothes and old shoes, and also a good day to leave the dog at home, since the epoxy gets all over the floor around the canoe as it drips off the hull. After giving the two coats of clear resin about half an hour to dry, it was time for the fairing filler.

The filler is added and mixed until it’s the consistency of heavy syrup [or thin yoghourt, if you prefer], and then it too is applied by squeegee. After several sticky hours, you end up with a hull that looks like this:

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Re-Canvassing a 1937 Old Town Canoe, Part 2

Posted in Canoe Restoration, Canoes, Uncategorized, tagged canoe building, canoe repair, canoes, Old Town Canoe, re-canvassing on July 14, 2013| 2 Comments »

With three good coats of varnish built up on the outside of the hull, it was time to stretch the canvas. On final precaution against the epoxy filler adhering was to spray the varnished hull exterior with a hefty coat of silicone mould release. If you do this, just remember that you’re also covering the floor around the canoe with slippery overspray and you’ll need to tread carefully until it wears off! (says the voice of experience).

The canvas is good old #10 cotton duck. For a canoe that will really see heavy service, you could go down to #8, but the heavier grade adds weight. At about 85 lbs, Clementine doesn’t really need to get any heavier. There’s a fair bit of information out there about canvassing and re-canvassing wood/canvas canoes, including The Wood and Canvas Canoe: A Complete Guide to its History, Construction, Restoration, and Maintenance by Rollin Thurlow and Jerry Stelmok, now sadly out of print, and of course videos on YouTube like this one.

There are different schools of thought about how to stretch the canvas: right side up or upside down, tacks or staples. Personally, I’m a right side up, tack man. It doesn’t really matter in the end, because anything that will stretch the canvas tight and secure it to the canoe will do the job. I’ve even done it outside between two trees using a small child to help weight the boat down. When the canvas is folded in half and stretched tight, the canoe hull is inserted and forced down into the envelope. Here, I’ve got sandbags in both ends and two shore poles pushing down from the ceiling. You want to get it good and tight.

Working out from the middle, the canvas is pulled up tight to the gunwale with a pair of wide-jaw vise grips or artist’s canvas pliers and tacked into place at each rib. With two people, you can work both sides at once. Here, my colleague Jeremy Ward is clamping the vise grips for another upward pull. The sign of a good job with the right tension is to have little “eyebrows” of puckered canvas above each pair of tacks when the pliers are released.

As you go towards the ends, it gets harder and harder to pull the canvas in towards the hull, usually somewhere around the ends of the decks. When everything is tacked but the two ends, it’s time to cut the canvas away from the stretching clamps.

Then, bit by bit, the ends and pulled tight and tacked. It’s not as hard as it seems to get the wrinkles out here, even on a hull like this one that has some hollow in the ends. By pulling on the bias, and occasionally removing and re-tacking some of the earlier fastenings, it will all come right eventually.

With one side tacked in place, the canvas is cut close to the tack line and the process is repeated with the other side folded over the first. Some people like to add a little glue to help hold the ends in place, but be careful not to add too much as it may affect the adhesion of the filler later on.

Next it’s on to the filler.

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Re-Canvassing a 1937 Old Town Canoe, Part 1

Posted in Boat Restoration, Canoe Restoration, Canoes, Sailing Canoes, Uncategorized, tagged canoe building, canoe repair, Old Town Canoe, re-canvassing on June 9, 2013| 2 Comments »

On January 20th, 1937, my 17′ Old Town HW-model canoe was canvassed at the factory in Old Town, ME. On April 28th, 2013, I decided that at 76 years and 14 weeks I had probably gotten my money’s worth out of that first canvas skin (which I hadn’t paid for anyways!), and so it was time to re-canvas. A couple of years ago, I wrote about finding the canoe and making the decision to try and revive the original canvas instead of replacing it. Turns out to have been a good strategy, and it gave me many miles of paddling and sailing. It also helped me name my new canoe. The salvage job on the original canvas had left the canoe with a rather, shall we say, “textured” look, and this, combined with the Princeton Orange colour led inevitably to the name Clementine.

The first step was to get the hardware, outwales, keel and old canvas off. The spruce outwales were held on with the original slot-head brass screws, and they were pretty well secured in their countersunk holes by years of varnish buildup. I’m always reluctant to use a slot bit with an electric driver because it’s so easy to have the bit walk out of the slot if it’s at all out of alignment, so I turned to a tried and trusted method for removing the outwale screws.

With a simple socket attachment that takes standard 1/4″ hex shank bits, your brace and bit can be converted into a high-torque, low-speed screwdriver that’s very useful in situations where you have to proceed carefully but also apply considerable force. You do own a brace and bit, don’t you? The attachment is available from Lee Valley tools, among other retailers, for under $12.00. There’s also one for sockets which is very useful for freeing stuck nuts and bolts. I never cease to wonderat how surprised people can be to see simple, non-powered tools in use. A typical comment in this case was “don’t remember the last time I saw someone using one of those.”

After the outwales were off, I removed the rest of the hardware, including the bolts that held the external keel on and the stembands. The stembands are the original bronze and I’m hoping to re-use them, so they were labelled and stored.

Then, it was time to peel the canvas. I was pleased to find that the planking was in excellent shape and that there were no hidden pockets of rot. Traditional canvas filler can take more than a month to dry after it is applied. Because I was foolish enough to embark on a re-canvassing project at the beginning of the boating season and not the end, I was hoping to find a quicker alternative. My friend Dick Persson, proprietor of the Buckhorn Canoe Company, has been using an epoxy-based filler that dries in days, and not weeks or months, so I decided to use that. Epoxy is know for being rather sticky, so I needed to take an additional step before putting the new canvas on.

I sanded the exterior of the hull with 80-grit to take out the re-saw marks and then built up three coats of varnish, topped with a healthy spray of silicone mould-release. In the event that any of the epoxy penetrated all the way through the canvas, this would prevent the canvas from becoming glued to the hull. I may not be around for the next re-canvassing, particularly if it’s another 76 years away, but it’s always good to plan ahead.

To be continued.

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Fixing the Rudder: Why Does Everything Take So Long?

Posted in Boat Building, Sailing Canoes, Uncategorized, tagged boat building, canoe building, sailing canoes on September 2, 2012| Leave a Comment »

Along with the big questions, like “Why are we here?” and “What is the meaning of life?” I often ask myself “Why does everything take so long?” Many of my projects seem to go on and on and on. Here’s a case in point.

When I created the hard-chine plywood 16-30 canoe, I needed to put a yoke arm on top of the rudder. This is because the mizzen mast is between the rudder head and the tiller. The older cruising sailing canoe and canoe yawl designs often used rope or, on J.H. Rushton boats, delicate little brass chains, to connect the rudder yoke to the tiller yoke. Here’s an example from a Mersey canoe in W.P. Stephens’ Canoe and Boatbuilding: A Complete Manual for Amateurs.

Some of the canoe yawls used a bent tiller that allowed just enough space to put the helm hard over, as on Iris, also depicted in Stephens’ book:

Neither one of these works for the 16-30, since you need something to take out to the end of the seat with you. The original 16-30s used a rigid tiller rod connecting a single yoke arm on the rudder head to a tab on the crosshead steering gear. This is a modification of the “Norwegian Tiller,” which has a single yoke arm on the rudder head with a long rod extending forward. The 16-30 set-up is more like a bell crank (for those of you who used to fly control-line model aircraft), and this is what I used on the new 16-30. Here’s the rudder end:

And here’s how the tiller rod connects to the cross-head:

The original 16-30s often had beautiful soldered, brazed or forge-welded metal hardware, but I was trying to keep this affordable, which is where the scaffolding parts that make up the cross-head comes in. In order to brace the single yoke arm, I epoxied and bolted an aluminum L-bracket underneath and epoxied the two plywood pieces together:

It wasn’t the strongest arrangement in the world, but it lasted for several years and other new-generation 16-30s were outfitted the same way with no problems. Then, I went to Sturgeon Point. I’d been asked by the Sturgeon Lakes Sailing Club to come and give a talk on canoe sailing, which had been a big part of summer life there at the end of the 19th century. Here’s a typical summer scene from the photo collection of the City of Kawartha Lakes Archives:

So far, so good, except that if I’m going to demonstrate canoe sailing I should probably have a sailing canoe, no? I have dear old Clementine, the lateen and leeboard-rigged 1937 Old Town, but I don’t actually own a 16-30[!]. I’ve been too busy drawing plans and teaching classes and teaching people to sail them to get around to building one of my own. So, I needed to make a side trip to the Antique Boat Museum in Clayton, NY, to borrow 16-30 #2, Somethin’ Else, which I had built when I worked there a number of years ago. When I picked the boat up, I learned that vulnerable rudder/yoke right-angle joint had gotten a good knock, and needed fixing. I took it apart and put it back together again the same way and saddled up the Subaru to go to Sturgeon Point.

The day we were supposed to sail was pretty blustery, but I set the 16-30 up and launched anyways. As we waited for the other participants to come down, two of us held the fully-rigged boat off the dock. As the wind and chop continued to rise, a large wave picked the boat up and dropped her down hard right beside the dock, catching the protruding yoke arm and breaking the joint again. That was the end of 16-30 sailing that day, though an intrepid club member did manage to get Clementine out before a rain squall closed everything down.

So, the yoke was broken again and there didn’t seem to be much point in repairing it the same way. I thought about a bent piece of aluminum that would be wide enough to fasten securely to the rudder and could also form the yoke arm itself. First step was to make a pattern and get the piece out of some 5/32″ leftovers I had in the shop.

Next issue was how to bend the aluminum. A test on a piece of scrap revealed that the 5/32″ was too thick to do the usual vise-and-wooden-block method. The resulting bend wasn’t very satisfying.

I needed a better way to bend the aluminum, and I don’t have access to a metalworking shop or a big press brake. After a little consultation, I picked up a 4-ton bottle jack on sale and that, together with some threaded rod and odds and ends, produced what I hope will be a useful piece of equipment: The Bend-O-Matic.

The angle iron on the jack’s stem mates up with another identical piece that’s cradled in an oak block at the top. As the two are jacked together, the bend is formed:

It sure looks stronger than the old one. Hope to take it sailing soon, I’ll let you know how it works out.

And that’s how a simple “sure, you can borrow the boat for a little while but I think you’ll need to look at the rudder” turned into two repairs and a new piece of shop equipment.

Until next time. . .

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What Boat To Build Next: Part 4

Posted in Boat Building, Boating, Boats, Canoes, Sailing Canoes, Uncategorized, tagged boat building, canoe building, canoe design, canoe history, sailing canoes on February 4, 2012| Leave a Comment »

Back in the second post in this series, I was thinking about how to translate the arc bottom of the original sailing canoe into something I could build in stitch and glue. Using the original linesplan, I’ve modeled several different version of the hull in Delftship that allow me to make some numerical comparisons between them. All I’ve changed in each case is the number of chines and the underwater shape–everything else is the same (with the exception of some small changes to the bow profile to accommodate an additional chine). The design waterline and draft of 4″ are as on the original plans, and all these hulls are shown in a full bow-on view.

Here’s the original arc-bottomed hull, which displaces .117 short tons, or 234 lbs.

Here’s the same hull with all of the arc taken out of the bottom sections so that there’s just a straight section from chine to keel. This results in a significantly lower displacement of only .075 tons, or 150 lbs. How much displacement do we want or need? Well, I’d say something at least equal to the original hull. I’m also keeping in mind the displacement of my hard-chine 16-30 hull, which is .133 tons, or 266 lbs. From my experience in building and sailing those boats, they float pretty much on their marks with a sailor of average weight, so there’s a good comparison for what displacement we should shoot for in a two-masted, decked 16′ sailing canoe built in stitch and glue. I don’t think 150 lbs is going to do it.

Here I’ve added another chine and pulled it down amidships to make a nearly flat bottom. I may have overdone it on the extra volume, though, because now our displacement is up to .139 tons, or 278 lbs. I’m not sure we need quite all of that.

If I introduce just a little deadrise into the midships sections, leaving the ends unchanged, the displacement decreases to .128 tons, or 256 lbs, which is pretty close to our 16-30 hull.

So far, so good. The next step is to add the deck and deck camber, put the bulkheads in the right places instead of just at a uniform 1′ interval and expand the individual hull panels. Then, I’ll buy some balsa wood and make a 1 1/2″ – 1′ model.

Until next time. . .

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What Boat to Build Next: Part 3

Posted in Boat Building, Boating, Boats, Canoes, Sailing Canoes, Uncategorized, tagged boat building, boating history, canoe building, canoe history, canoes, sailing canoes on January 31, 2012| 2 Comments »

As I mentioned in the last post, I started to do some work on the original linesplan for the late 19th century decked sailing canoe Isalo to explore making the arc bottomed hull suitable for the flat panels of stitch-and-glue construction. I began drawing by hand, but then I decided to put the lines on the computer and see what I could come up with. To do this, I used a hull design program called DelftShip, a development of an earlier program called Freeship (which is still available from SourceForge). Both programs are powerful, full-featured naval architecture packages, and both are free. Once you figure out how to use them for canoes, you could also design yourself an oil tanker, passenger ship or tug if you’re so inclined. A professional version of Delftship with more features is also available for €150, with the latest version slated for release in late February. These programs have a steep learning curve, no pun intended, but are well worth the investment of time.

One thing they’re particularly useful for is projects like Isalo, because with them you can import a scanned linesplan of unknown scale, such as you might find in a magazine, and, as long as you know a couple of the principle dimensions, draw new fair lines on top of the original. There’s a handy tutorial about how to do this, based on, of all things, Leo Friede’s legendary 16-30 sailing canoe Mermaid on the WoodenBoat Forum. If you use this tutorial, go through it with the DelftShip manual in front of you, because author Bruce Taylor leaves out a couple of important steps whose absence will drive you crazy until you also read the DelftShip tutorial on Reproducing An Existing Lines Plan, which you can download from the company’s web site.

Even though I’m planning to add one or more chines, I thought I would start by getting Isalo‘s original arc-bottomed hull re-drawn in DelftShip. After a weekend’s worth of work, here’s what I’ve come up with:

This is the main Delftship window with all four views: perspective, profile, plan and body plan. Much as with regular lofting and fairing, you alternate between them, working iteratively on each one to gradually firm up and reconcile the lines. In each case, the starting point is the original linesplan in a background layer, on top of which you work with curves and the control mesh to shape the new lines.

Here’s the profile with the three main lines defined: the centreline of the hull [composed of bow, stern and bottom], the chine and the sheer.

And here’s the body plan, with the control curves [red] and stations [green]. Once you begin to develop the wireframe, you can add the other side of the hull and shade it to check on your progress.

One of the most useful features for a project like this is that you can also run a developability check on the panels to see if they can be gotten out of plywood, which nominally doesn’t like to do compound curves, though you can torture it into shape to a certain extent. When you use that feature, the program adds red shading to show you areas that can’t be expanded into flat sheets.

DelftShip is telling me that the sections below the chine aren’t developable, which is not surprising since they’re still the original rounded arc bottom. The good news is that I seem gotten the topsides pretty straight, as it’s all green from sheer to chine. The next step is to go back to the body plan and make sure I’ve added enough curvature to the bottom to capture the volume of the original hull below the waterline. After that, I’ll ask DelftShip to calculate the hydrostatics to get some numbers against which I can compare my multichine versions as they’re developed.

Until next time. . .

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A New Canoe Sailing Magazine

Posted in Boat Building, Boating, Boats, Canoes, Sailing Canoes, Uncategorized, tagged canoe building, canoe history, canoes, International Canoes, sailing canoes on January 3, 2012| Leave a Comment »

I recently received a note from my friend Ed Maurer down in Florida. A couple of years ago, Ed took the brave step of starting a new magazine called Canoe Sailor, which is a noble project in its own right. In this case, it was even better because the magazine was focused on, of all topics, sailing canoes–imagine such a thing!

Ed’s note let me know that he’s just re-formatted the original Canoe Sailor a new, all-digital page-turn publication called Skinny Hull. In his own words,

Skinny Hull covers sailing canoes and kayaks, proas and similar style boats, Chesapeake log canoes and a variety of purpose-built two- and three-hull boats that are essentially canoes (or kayaks) with outriggers. (We’re even working on bringing you ice boat sailing!) So, essentially, if it mounts a sail and has a skinny hull we cover it!

The first few issues will contain archived content from Canoe Sailor, and there’s some good material there. Like any editor, though, Ed will be looking for new content too. I’m going to try do do my part, and I’d encourage anyone who’s interested in contributing to contact him at editor@canoesailingmagazine.com, and also to subscribe, which I’m going to do as soon as I finish writing this post.

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What Boat to Build Next: Part 2

Posted in Boat Building, Boating, Boats, Canoes, Sailing Canoes, Uncategorized, tagged boat building, canoe building, canoes, sailing canoes on December 31, 2011| Leave a Comment »

As I mentioned in the last post, I’ve started to explore whether the 1893 sailing canoe design Isalo would be suitable for re-designing for construction in modern materials. One of the first big questions to is how to build the boat.

If I follow through with the idea that this cruising canoe and the 16-30 are “bookends” that between them cover a nice range of sailing canoe history, then it would be best if Isalo was rendered in stitch-and-glue plywood. This has worked well for the 16-30s, proving to be light and durable and reasonably quick to build.

The body plan for the 16-30, showing its single chine hull made up from four separate stitch-and-glue panels.

The original 16-30 was a perfect choice for stitch-and-glue construction, with a single hard chine and a V-shaped bottom. The only difference from the original to the new version was that the plank keel was replaced by a filleted epoxy joint.

An interior shot of the original 16-30, showing the top of the plank keel. The bottom planks converge in a slightly rounded V-joint on the bottom of the hull.

The interior of the plywood 16-30, showing the filleted and taped seam on the interior bottom.

Our original 1893 canoe, however, has an arc bottom, much like a Star-class keelboat.

Body plan for Isalo from the original 1893 drawings.

You could likely make the plywood conform to this shape, but not in stitch and glue. In order to get the compound curve in the bottom panels, you’d have to introduce some interior framework, as on the 15 1/2′ sailing canoe Zephyr, and this would take us away from the idea of making both canoes as similar in construction as possible.

The arc-bottomed sailing canoe Zephyr, published in Yachting in 1925, was designed for traditional batten-seam plank-on-frame construction.

There are (at least) three possible ways to tackle the bottom of the new canoe, starting with the original lines. Here’s a sample section.

The original body plan at midships, with an arc bottom.

Option one is to take all of the arc out of the bottom and connect the chine and keel with a straight line, as on the 16-30:

Bottom section straight from chine to keel, with the dotted line showing the original arc section.

As you can see from the sketch, this takes a fair bit of volume out of the bottom. It might be ok, but I wouldn’t know until I did some hydrostatic calculations. Another option would be to introduce a second chine below the waterline.

The straight section from keel to chine has been broken into two parts by the addition of a second chine, with dotted line showing the original arc section.

This option preserves more of the original volume, but we’re now up to six hull panels, which will be more work to construct. Another way to do this is to give the canoe a narrow flat bottom panel:

Introducing a flat bottom panel equals or exceeds the original volume of the arc-bottom hull.

There are a few reasons why I like this option: it only needs 5 panels; it will make the boat easy to beach; and finally, the flat bottom will give a good solid anchorage for the centreboard trunk and mast steps without the complications of fitting them over a filleted centre seam. I built and sailed a little canoe with a hull like this for several years in the 1990s and it worked quite well. It was designed by John Bull, who used to own Solway Dory in the UK. He’s since retired, but the company continues, though I don’t believe they offer this design any more. The only drawback is that you need to install some floorboards so that you’re not sitting in any water that happens to come aboard!