One-Sheet Baby Canoe Part 2
By Gaetan Jette - Sherbrooke, Canada

Part 1 - Part 2 - Part 3 - Part 4

Construction Begins

I took many photos during the building phase, but I did not write down a log. I'll try to comment the building as best as I can remember. This will be a detailed account, too detailed perhaps for those who have already built a few boats. But since this will be mostly a pictorial essay, it will be easy for readers to skip what is old news for them and concentrate on the more interesting details (I hope). Now, I am a novice boatbuilder and I am not a highly skilled or experienced woodworker either. I do not claim this is the best way to build a boat, it's just how I managed to do it.

Here is the lumber material list for this project:

Description Quantity Use
Plywood, 1/8 in. thick, 4 ft. by 8 ft. 1 Hull and paddle blades
2 x 4 lumber, 8ft. long 4 Backbone and center frame, seat mold
2 x 6, 12 ft. long 1 Inwales, outwales
1 x 4 plank, 8 ft. long, softwood 2 Keel and other stuff
1 x 4 plank, 8 ft. long, hardwood * 1 Paddle shaft cutting jig
1 x 2 pine, 8ft. long 1 Edge of center frame
Waferboard, 1/2 inch thick, 4 ft. by 8 ft. 1 Support for keel assembly, plywood marking; patterns for paddle blades, center frame
* or any plank with sharp, square edges

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I used marine grade plywood, but a cheaper luan ply might do. The few luan samples at the local lumberyard were not in good enough condition for the job. The epoxy gallon I purchased was more expensive than the plywood anyway.

 
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Lines are scribed across the width of the sheet, six inches apart. A drywall T-square proves handy for that. Then all dots for one side of the boat are marked. The arrows on the top and middle planks indicate where are the bow and the top: these 2 planks are not symmetrical.

 
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With the waferboard used as a backing, nails are driven in the plywood. I used an aluminum flat bar as a batten to trace the patterns.

 
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A flexible plastic ruler is used for tracing the sharpest bends.

 
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The bottom plank is traced right at the edge of the sheet. Nails just outside the plywood, wrapped with electric tape, allow to keep the curve fair as it moves away from the edge.

 
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A "rough" cut is made to split the sheet in two, but that cut must be done as close to the line as possible, due to a very tight spacing between planks. The gap along the center of the sheet is under a quarter inch wide.

 
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The two halves are clamped together and the area used for the breasthooks is cut off.

 
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Tracing the patterns for 4 paddle half-blades (top) and 4 cover plates (bottom) is made easier by cutting patterns in the waferboard.

 
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Here is the center frame. 1 x 2 pine is screwed along the edge. The notch at the bottom is where the keel will be fitted. The notch at the top is for the off-center backbone.

 
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The parts for the keel are dry fitted. You can see that all the patterns were cut on one side of the waferboard sheet, leaving the full length available for the keel assembly.

 
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Because this boat is built with a keel, I chose to mark and pre-drill all the stitching holes before assembly.

 
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A few machine screws are placed in the stitching holes to keep the 2 plywood layers clamped together. Each part is rough cut with a hand saw and then a coarse metal file is used to trim down to the scribed lines. Not the fastest way to do it, but I find it too difficult to control a circular saw freehand.

 
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My Workmate proved handy when dealing with smaller parts like the paddle cover plates shown here.

 
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One sheet, one boat. Some assembly required...

 
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Moving to boatyard number 2. This project would never have happened without my brother letting me use his utility shed. This is where I spent most of my spare time that summer.

 
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The keel is assembled with loose tongue and grove joints. The tongues are cut from the leftover plywood strips. The grooves are cut on a table saw, just one saw kerf wide. This was a bit tight however, so some sanding was required for the tongues to fit. The parts are screwed down on the waferboard; a plastic film prevents the parts from gluing to it.

Unfortunately, my first epoxy batch didn't cure. After one week, I had to disassemble, scrape and clean everything and start all over. Fortunately, this was also my last batch that didn't cure.

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The keel curves are scribed the same way as the plywood sheet was.

 
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The sharpest bends require more nails. You can see here the tongues in the joints.

 
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The keel is cut and the edges are routed with a quarter-inch radius bit.

 
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The stems are left longer in order to screw them to the backbone. The wide stem with all those holes you see here didn't prove to be such a good idea when dealing with the epoxy fillets inside.

 
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The keel, center frame and backbone are screwed together. The 2 x 4s at each end allow to the whole assembly to rest on sawhorses, either right side up or upside down.

 
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The frame has to be braced in every possible direction.

 
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The top planks are attached with screws to the center frame, while the ends are attached with plastic ties to the stems.

Some stitch and glue designs use no frame during construction, as described in Sam Devlin's book "Devlin's Boat building" (at least for small boats). Some designs use quite a few permanent frames, like Phil Bolger's Cartopper. My design falls somewhere in between, using a temporary center frame and a permanent keel. I felt this would produce a straight hull with little warp or twist, without having to build several frames, and without some tricky alignment procedure. As long as you glue the keel on a perfectly flat surface, and that the 2x4s used for the backbone are straight, the resulting hull should be straight enough.

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The middle planks are attached next.

 
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The bottom planks are attached to the middle planks first. The keel and bottom planks are then attached with plastic ties in one loop: for each hole in the planks there is a pair of holes in the keel.

 
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A few screws are necessary to force in place the ends of the bottom and middle planks. Instead of pulling the planks tight against the stems, the slim plastic ties stretched under high tension.

 
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A few screws, backed by small plywood squares, are also needed on the bottom chine near the bow and stern. These plywood squares were also cut from the leftover plywood strips.

One mistake I made was to assume that the 4-inch planks I bought were 3/4-inch thick. It seems that construction grade planks are 11/16-inch thick nowadays. Well at least in the area where I live. The center frame was built for a 3/4-inch thick keel. As a result, the edge of the bottom planks could not be pulled tight against the keel, especially near the center frame. This made it harder for the edge to follow the fair curve of the keel. A few match-size splinters, slipped under the plastic tie loops (on the inside) helped maintain proper alignment along the keel.

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Small splinters are used to fair the keel side of the bottom planks. This photo was out of focus so I sketched over it.

 
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The first epoxy fillets are done on the inside of the keel. They have to stop short of the center frame. I used the round corner of a plastic spreader to shape the fillet. 3-inch fiberglass tape spreads over the keel and both fillets.

 
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In order to achieve fair curves along the chines, temporary outwales were first screwed and clamped along the sheerline. These temporary outwales will later become the permanent inwales.

 
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Epoxy fillets have now been done on both chines inside. I used the lid of a cottage cheese plastic container (about 4-1/2 inches wide) to spread the epoxy for the chine fillets.

 
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Before starting the epoxy work on the outside, I had first to correct a mistake: I forgot to wrap the edge of the frame with some plastic film. Luckily, this is a small hull. Just a few screws to take off and the problem was solved.

Before doing the epoxy fillets on the outside, the plastic ties are cut off first with cutting pliers, then trimmed flush with a wood chisel.

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The fiberglass tape has been done on the outside. The tape on the keel covers the epoxy fillets on both sides of the keel, more or less. It had to be cut in sections near each end: the sharp curve would have caused too much wrinkles.

 
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The fiberglass fabric is laid on the boat and cut roughly to size, in two halves. I decided to cover only the bottom planks, with some overlap on the bottom chine and along the keel. It might have worked better to unfold the fiberglass fabric a few days in advance. The wrinkles of each fold proved difficult to cover with a minimal amount of epoxy.

 
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Before the final fairing along the stems, a notch is cut in the stem where the outwale will rest. Lines are scribed with a pencil, a sawcut is done on those lines. Then a chisel, with the blade resting flat on the top plank (at an angle so the chisel handle is beyond the edge of the top plank) is used to clean that notch.

 
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Time to fair the sharp edges of fiberglass tape with thickened epoxy.

 
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Coating with clear epoxy. The fiberglass weave takes several coats, which leads to the proverbial epoxy drips.

 
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Looks shiny form afar, but not truly smooth: still more fairing to do.

 
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Still more fairing: I even resorted to put the hull on its side in the hope of reducing the dripping problem.

 
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While epoxy was curing, I had time to install the first few inwale spacers.

 
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The paddles are assembled for a dry fit check.

 
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The paddles are glued using lightly thickened epoxy. The screws are coated with beeswax to avoid sticking to the epoxy while curing. Short lengths of 2x4s in between the screws allow to apply pressure with the improvised weight (the toolbox).

 
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The epoxy has cured, but the tip of the blades didn't get glued perfectly.

 
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Using a couple of spring clamps and cleats, the paddle blade tips are glued.

 
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Fairing the paddles with thickened epoxy was next, one side at a time.

 
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At long last, the fairing on the outside is arriving at an end.

 
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The hull is removed from the backbone and frame; now the inside has to be faired.

 
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Fiberglas tape has typically one edge that is thicker than the rest of the tape. Coated with epoxy, this creates a bump that must be smoothed. I trimmed that rough edge by using a small Dremel tool with a router attachment, both outside and inside (shown here).

 
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I chose to build seat braces with a curve, in the hope it would be more comfortable. Here that curve is scribed on a form.

OK, that's enough for this time. The next part will show more work on the paddles and fitting the inside of the boat.

On to Part 3


REFERENCES

  • Samual Devlin: Devlin's Boat Building, International Marine, 1996
  • Philip C. Bolger: Boats with an Open Mind, International Marine, 1994
SAILS

EPOXY

GEAR