Build Your Own Canoe
Excerpted from:
"How to build your own boat from scratch"
by John Traister

The construction of a canoe is not easy. It is a task that requires weeks of careful and tedious work even for the professional. The amateur, therefore, should not attempt building a canoe—at least not by standard methods—unless he is a very painstaking workman and well experienced in the use of woodworking tools. Yet an amateur can build a canoe if he'll address his energies to the simple plywood canoe described in this chapter!

Before getting into the construction details, however, let's take a look at conventional canoes so that you will have a better idea of what you're shooting for. There are five distinct tvpes of canoes used in North America: the all wood design; the canvas canoe; the almost-extinct birch bark canoe; the aluminum canoe; and the fiberglass canoe. All other types are hybrids. The authentic birch bark canoe is only built by certain Indian tribes and by a limited number of non-Indian builders who produce only a few each year. These canoes are extremely hard to obtain and even harder to construct—just like the canvas canoe.

To understand the procedures for building birch bark or canvas canoes, let's briefly study the various steps. This introduction will help you to appreciate the simplicity of the plywood canoe described later.

The material for the ribs and lining is perhaps the most critical consideration of the entire construction. These members should be made from cedar, balsam, spruce, or if these woods aren't available, from some other type of light free-bending wood. This lumber should be split, shaved and planed to a thickness of 1/4 to 3/8 inches and a width of 2 inches for the average size canoe. Notice that we said "split." If sawed, these members will not stand the bending
required later.

 

Figure 9-1 Method of bending and drying rigs for a conventional canoe

Immediately after each rib is made, it should be placed in water to prevent drying until the time when it will be bent into its finished shape. After enough ribs have been made, they should be placed in a steam box for a few minutes, then removed and bent over a form as shown in Fig. 9-1. Two forms will be required. The ribs will be air dried on the forms for several weeks. Notice that the ribs placed first on the forms (Fig. 9-1) will be of the proper size and shape for the ends of the canoe, while those on the outside of the pack are for the center. In using the ribs after they have dried, the builder works each way from the center. Because this procedure requires two ribs of the same size and shape, two forms will be needed. In other words, the ribs bound on a single form as in Fig. 9-1 are only enough for half of one canoe.

Figure 9-2 Two pieces of White Oak or other tough wood should be shaped as shown here

While the ribs are drying, begin work on the lining. The lining is made up of strips about 2 inches wide and 1/8 inch thick for canoes up to 15 feet in length. Cedar is usually the type of wood used. Again, it is best if these strips are split, not sawed. Afterwards, they should be planed to shape. The gunwales which come next should be made of tough wood like white oak. They consist of two pieces and should be shaped as shown m Fig. 9-2. It is best to split these from a tree and shave them down to a 1" x 1" size to facilitate bending them around the corners. For a 15-foot canoe the gunwales should be cut 15 feet long, even though the curve (Fig. 9-2) will shorten them somewhat. However, the vertical ends of the canoe also curve and this will return the total length to 15 feet when the craft is completed. The gunwales should be steamed and bent as shown in Fig. 9-3 and allowed to dry on a form.

Figure 9-3 Canoe gunwales steamed and bent in this position and allowed to dry on a form.

Refer again to Fig. 9-2 and notice that four crossbars (braces) are used fora 15-foot canoe. These should be mortised into place as shown and fastened with a few small boat nails. The two crossbars closer to the center of the craft should be about 2' 8" long while the outer two—each placed about 2 feet from the ends—should be about 17 inches long.

The strips used for the lining must be fastened together at each end with cord and hung inside the canoe while the ribs are installed. The ribs are then trimmed to the required length, and sprung - starting at the center and working alternately towards either end - under the gunwales. They should be spaced about a half-inch apart. Once the ribs are in place, the lining strips should be fitted together neatly and tacked to the ribs. Before the end ribs are placed in position, however, a narrow half round strip should be stretched and bent to the proper shape and fitted in to cover the seam. A thin narrow strip of wood should then be nailed to the top of the gunwales to protect the edges of the birch bark or canvas body fabric.

If you want to try your hand at covering the canoe with birch bark, it can be done, but good bark has become so scarce that it's almost impossible to find. Check into this before beginning. The Indian method was to sew up the bark with split and boiled spruce or tamarack roots while the bark was still fresh from the tree. Modern materials, however, will make this phase of the construction go easier. Still, at best it's slow work, and in olden times several squaws would work together on the sewing, so that the job could be completed before the bark became too brittle.

All of the bark—including that portion attached to the gunwales—was sewn (not nailed) to the framing and applied to the craft with the flesh side out. To give the canoe the proper shape, two sets of stakes were driven firmly into the ground and the ends of the canoe pinched between the stakes. The ends rested on blocks of wood and the inside was weighted with stones to give curve to the bottom. The seams were then daubed with boiled spruce gum which
hardened immediately and made the canoe perfectly waterproof.

Length 14 feet 9 inches Width 6 feet

Figure 9-4 Shape of 12-ounce double-filing
duck (canvas) prior to applying to Canoe

If you prefer to go with a more conventional canvas covering over the cedar lining, obtain 12-ounce double-filling duck in one piece and cut it to the shape shown in Fig. 9-4. The canvas should be about 6 feet wide and - to allow for good seams - about 8 inches longer than the canoe. Fasten the canvas to the gunwales on the outside, and tack to the top edge with very small flat headed tacks placed close together. Fasten the ends first, then the center, and finally midway between. The ends of the canvas should then be sewn up with the seams inside.

At no time during the construction of the craft should the canvas be allowed to become wet or even damp and possibly cause shrinkage. Furthermore, wet canvas often won't stretch properly. After the dry canvas has been stretched into place, you're ready for the final steps of oiling and paindng the canoe. It is customary to administer liberal applications of hot boiled linseed oil to the canvas. When the canvas has dried thoroughly, paint it with any type of marine paint. Only the canvas, however, should be painted; the bare wood should be primed with a clear wood filler and varnish. Figure 9-5 show's what the finished canoe should look like.

Figure 9-5 A finished canvas-covered canoe

The most primitive type of canoe is the wood dugout which was recorded in ancient history. It is still used today in some South American countries and in other parts of the world. Dugout canoes were built by felling a suitable tree and then chopping and burning it. With the trunk lying on the ground, several workers would carry on the chopping and burning procedure until one side of the trunk was slightly flattened. Then they would hollow out the craft with more chopping and burning. These very crude shaping procedures were just about all that the fabrication consisted of.

Modem wood canoes are constructed of wood planking or laminated sheets molded into shape in the way that fiberglass and aluminum canoes are formed. The type of canoe described later in this chapter for amateur building consists of a combination of wood and fiberglass so that the construction can be accomplished by the first-time boatbuilder.

Unlike the canoes described previously, this design only requires one rib where the others need a dozen or so. Moreover, the ribs don't have to be steamed and bent - they are merely cut from plywood or whole lumber. In place of the cedar skin so difficult to split and plane on classic canoe designs, plywood is used; elsewhere on the craft, fiberglass replaces canvas and birch bark. The result is a canoe that is tough and scrape-proof. Better yet, you can build this canoe in a tenth of the time it would take you to turn out a multi ribbed conventional canoe.

Figure 9-6 Square-stern model designed
for use with outboard motor

This craft can be built with a square stern for use with an outboard motor (Fig. 9-6), or as a double-ender (Fig. 9-7) for paddling.

Figure 9-7 Drawings of square-stern
model and double-ender (click to enlarge)

Before beginning construction, obtain these Materials.

Start construction by mating a full size drawing on heavy paper of the planking pattern (Fig. 9-8) that will cover a quarter of the hull. Use a 1/4" x 3/8" batten about 8 feet long to draw the curved sheer line and bow lines tangent with the 12-inch radius. Cut out the pattern and place it on a 4' x 8' sheet of 1/8-inch plywood as shown in Fig. 9-8. A keel centerline drawn on the plywood will help to locate the pattern. Draw around the pattern to lay out one side, then flip the pattern over and lay out the other side. When cutting the plywood, make a slit the width of the saw blade along the centerline, stopping at a point 48 inches from the bow (as indicated in Fig. 9-8).

Figure 9-8 Planking pattern and layout

Figures 9-9a, 9-9b, 9-9c (click to enlarge)

If you are going to build the double-ender paddling canoe, lay out and cut another sheet of 1/8-inch plywood as you did the first one. If the square-stern canoe for use with an outboard motor is your choice, do not lay out or cut the second sheet of 1/8-inch plywood. Set these sheets of plywood aside until later and make full size patterns of the parts shown in Figs. 9-9A, B and C. Note that some parts, such as the transom and transom knees, are used only on the outboard-type canoe. Omit these if you build the double-ender. Cut out the patterns and transfer their shapes to plywood or lumber according to the drawings. When fastening the transom frame pieces to the 3/8-inch plywood, coat the contacting surfaces with waterproof glue and use 1-inch galvanized boat nails or 1-inch #6 flat head screws arranged in a staggered double row spaced about 2 inches apart.

Figure 9-10 Building framing with dimensions and layout for keel and other attaching members (click to enlarge)

Next, cut the keel (Fig. 9-10) to size and shape. Note that the double-ender keel is tapered at both ends and is somewhat shorter than the keel of the outboard-type canoe. Now. cut a 1/2-inch deep notch in the 3/4-inch plywood midship frame (Fig. 9-11) for the keel. Since two 1/8" x 6" plywood pieces—cut from scraps of plywood sheets used for planking—will serve as butt bands to reinforce the seam where fore and aft planking join, cut a notch 6 inches wide and 1/4 inch deep in the keel so the butt band straddles the midship frame (Fig. 9-11).

figure 9-11 Midship frame and transome are kept in alignment with braces toe-nailed to floor and clamped to frame parts. (click to enlarge)

To assemble the keel and butt bands to the midship frame, first fasten keel to frame with glue and one I 1/2-inch #8 flat head screw, making sure the frame is square with the keel. Then coat the keel notch and edges of the midship frame with glue and bend one of the 1/8-inch butt bands around the frame (Fig. 9-11). fastening with 1-inch boat nails spaced 3 inches apart. Now coat the contacting surfaces of the first and second butt bands and wrap the second band over the first, fastening with 1-inch boat nails as before. Again check to make sure the keel is square with frame and clamp the butt bands to the keel on both sides of the frame until dry.

Next, make a building form consisting of a 2" x 4" mounted at a convenient working height on top of legs in the manner of a saw horse as in Figs. 9-10 and 9-12. Cut one planking bracket (Fig. 9-10) if the outboard canoe is to be built - two if the double - ender is your choice - and clamp to a scrap piece of 2" x 2" stock mounted 38 inches from the center line. Now place the keel and midship frame assembly in position on the form; mark and cut a notch for the midship frame in the 2" x 4" of the building form and clamp in place.

Figure 9-12 Midship frame and transom are kept in alignment with braces toe-nailed to floor and clamped to frame parts.

The end of the midship frame can be supported by erecting two 1" x 2" braces extending from the floor to the frame ends as shown in Fig. 9-12. Toe nail these supports to the floor and clamp them to the frame. The keel is then lifted up slightly, and the notch in the planking bracket is coated with glue and fastened with one 1-1/2-inch #8 flat head screw. This procedure is followed for both the fore and aft ends of the double-ended canoe. For the square-stern canoe, notch the previously assembled transom to the keel and fasten the transom and transom knee to the keel with glue and three 1-1/2-inch #8 flat head screws at each Joint. Be sure the transom is laterally aligned square with the keel. Support is achieved with 1" x 2" braces extending to the floor as was done for the midship frame. The bottom surface of the keel is then rounded off with a plane to insure good contact with the plywood skin.

The 1/8-inch plywood skin is bent to shape after it has been steamed or soaked in hot water. The latter process is accomplished by laying rags, burlap, or old rugs on the plywood and saturating the material with hot water. When the plywood is pliable enough to bend, coat the keel, the forward 3 inches of the butt band, and the contacting surfaces of the previously cut plywood planking. Then place the plywood on the frame and position the aft edge at the center of the butt band, thereby making a 3-inch lap. Start shaping the plywood to the frame by bending it around the butt band. Fasten the plywood to the butt band with C-clamps at the sheer ends and bend the bow ends down until the curved ends come together. Tie a rope around the plywood at the bow to hold it in place temporarily.

Make certain the plywood is accurately centered on the frame and then fasten to the butt band with a staggered double row of 1-inch box nails spaced about 1-1/2 inches apart. Clinch over the nails on the inside. Continue by pulling together the slit-cut edges along the keel and fastening them to the keel with 1-inch nails. Clamp the curved ends together with small C-clamps and fasten with glue and 1-inch nails clinched over. Wooden wedges driven under a steel band (from a packing box) wrapped around the plywood and held together with a C-clamp (Fig. 9-13) will keep the plywood in position until the glue dries.

Figure 9-13 One sheet of 4' x 8' plywood
planks forward half of the canoe

The aft planking is installed just like the fore planking on the double-ended model. For the square-stern model, however, do not cut the 1/8-inch plywood; rather, soak (as described previously) and wrap the plywood around the transom and butt band. Fasten the plywood to the framing members with glue and 1-inch box nails.

Do not move the hull from the building form for at least 12 hours after the plywood skin is installed - let the glue dry thoroughly. After the glue has dried, remove the clamps and lift the hull from the form. Place it right side up on sawhorses. Fit the breasthook to the pointed end of the canoe as in Fig. 9-7 and secure with glue and 1-inch nails. The double-ender has a similar breasthook at the other end while the outboard canoe design calls for two transom knees at the stern (Figs. 9-14a and 9-14b). Coat the contacting surfaces of the knees with glue and fasten to the transom with two 2-inch #8 flat head screws, and attach to the planking at the sheer line, using 1-inch boat
nails.

Figures 9-14a Details of transom stern knees and breast hook. (click to enlarge)

Rip a 15-foot length of 3/4" x 1.3/4" stock as shown in Fig. 9-11 for the sheer molding. Clamp in place on the outside of the planking at the sheer line as in Fig. 9-11 and mark the planking along the molding edges. Remove the moldings. Coat the contacting surfaces with glue and reclamp the moldings in place. Fasten the plywood to the moldings with 3/4-inch nails spaced 1 1/2 inches apart.

Figure 9-14b Plan and elevation views of square-stern and double-ended models with required dimensions

Make two sheer clamps (Fig. 9-9C) and half lap the ends to fit the transom knees. Notch the clamps to fit over the butt bands, coat all contacting surfaces with glue, and fasten with 2-inch #8 flat head screws spaced 6 inches apart. Then install the two 3/4" x 3/4" crosspieces and the thwart piece across the top of the midship frame as in Figs. 9-7 and 9-11.

Now turn the hull over, bottom side up. to Install the outside keel. Saw 15° bevels on each side of the keel as in Fig. 9-11 and make the length 13 feet 2 inches for the outboard canoe and 12 feet for the double-ender canoe. Next, taper the end of the keel down to nothing at the bow (Fig. 9-11). Taper both ends for the double-ender. Fasten with glue and 1-1/2-inch #8 flat head screws spaced 6 inches apart. Again turn the canoe right side up so that the buoyancy seats (Fig 9-7) can be installed. Make cardboard templates of the side pieces shown in Fig. 9-9. Locate the position of these side pieces from the midship frame (Fig. 9-11) and mark the inside of the hull. Since the templates are only an approximation of their shape, fit, mark, and trim each template individually so that it follows the inside contour of the hull. If you cut too much off a template, discard it and make a new one. A good fit is important because these buoyancy seats are actually flotation chambers that will keep the canoe and occupants afloat if capsizing occurs.

After fitting the templates, transfer their outline to 1/4-inch plywood and saw to shape. Make up the 3/4" x 1" seat frame and fasten the sides to the frame with glue and nails. Use fiberglass resin to coat the areas inside the hull that will be in contact with the seat sides and frame. Then, before the resin dries, place the seat in the hull. Next fasten with three nails driven through the planking into the seat frame on each side. To make a watertight seam where the seat sides meet the hull, make up a heavy paste-like mixture of fiberglass resin and ground glass fibers, and apply a 3/8-inch fillet of the mixture as in Fig. 9-11. Then glue and nail the 1/4-inch plywood top in place and seal all corners and seams with 2-inch fiberglass tape and three coats of fiberglass resin.

Covering the outside of the hull is your next step. First turn) the canoe upside down on two sawhorses and prop it up so that one side of the canoe, from sheer to keel, lies as flat as possible. If you are using 50-inch wide fiberglass cloth, cut the cloth down the middle to obtain two 25-inch wide pieces.

Mix about one quart of fiberglass resin and apply the substance to the entire side of the canoe, including the outside keel. If uneven absorption leaves dull areas or spots, touch up these with another coat of resin. Now place fiberglass cloth on the hull side so that one long edge is against the bottom of the sheer molding. Mix another quart of resin and apply to the fiberglass cloth, starting along the sheer clamp and working toward the keel, bow and stem. Keep stretching and pressing the cloth gently to remove any wrinkles as you saturate it with the resin. Do not mix more than a quart of the resin at a time because it sets up rather quickly and soon becomes unmanageable. Also have a pan of warm water with household detergent or soap handy to remove the resin from your hands.

When you reach the keel, wrap the cloth over it and trim off the excess cloth. Wrap the cloth around the bow and stem too. Then turn the hull over and apply fiberglass cloth to the other side, again overlapping the keel, bow and stern. Apply three coats of resin and allow each coat to harden before applying the next one. After the last coat has hardened, remove high spots with a disc sander and smooth the surface with fine sand paper.

For color, a pigment can be mixed into the last coat of resin if desired. For those of you who wish to paint your canoe, use two thinned coats of Dolphinite #9585 undercoat on the outside, followed with two thinned coats of deck and ship paint #9007. The inside of the hull will look good with two coats of Dolphinite #9400 rowboat paint. Molding and cross bars should be varnished bright.

Figure 9-15 Method of improvising canoe outrigger with 2" x 4" lumber, C-clamps and two innertubes

Any round bottom canoe with a small, flat shoe keel is ideal for stream and river travel but it does demand some balancing skill. For family canoeing, one or two outriggers will increase safety and are simply attached. An outrigger can easily be improvised with two lengths of 2" x 4" lumber, two innertubes, and four C-clamps. Cut the 2 x 4's into 6-foot lengths; center them across the canoe and clamp to the gunwales. Then stretch an innertube over each end of the 2 x 4's as shown in Fig. 9-15. A pair of simple outriggers like these will make any canoe as stable as a flat bottom john boat.

Figures 9-16-a,b,c,d&e Details for constructing outrigger and pontoon for canoes, kayaks, and rowboats

A single outrigger designed especially for the canoe described in this chapter can be built in a couple of hours. While this type is not any safer than the improvised, innertube types, it is somewhat more attractive and you may want to build one.

Figure 9-16 shows how to begin construction of the outrigger by laying out one of the sides on a piece of 1/8-inch plywood. You can obtain the required curve by springing a wooden batten (1/4" x 1/2" x 6") around the dimensions in the drawing. After sawing the first side to shape, use it as a pattern for the second side to insure that both sides are exactly the same.

To determine the exact size of the center piece, make a full size drawing of section A-A in Fig. 9-16 on heavy paper. Transfer the outline of the center piece to 3/4-inch stock and cut to shape. Now, lay out the top (Fig. 9-16) by using a batten sprung against measured points as you did for the sides; then saw to shape.

To aid in assembling the pontoon, make a holder (Fig. 9-16a) from scrap material. When finished, place the two sides in the V-shaped cutouts of the base and insert the center piece between them. Then with a flat file held between the edges of the pontoon sides that are to be joined, file a slight bevel on the edges as in the enlarged detail of section A-A in Fig. 9-16. Since the top piece fits inside the pontoon side pieces, the edges of the top will have to be beveled. To do this, temporarily clamp the edges of the sides together, place the pontoon top piece in position and mark for beveling. Plane and fit the top piece so that the beveled edges will make wood-to-wood contact with the sides.

Figure 9-17 Place pieces of paper between hull ans holder at bottom of V-blocks to prevent hull from becoming glued to holder.

Start assembling by fastening the center piece to the center of the underside of the top with four 1-1/2-inch #8 flat head screws. Coat all joining surfaces of the sides, center piece, and top with a thick mixture of waterproof glue and fasten the sides to the top with 1-1/4-inch galvanized shingle nails spaced about 2 inches apart. Then clamp the edges of the sides together (Fig. 9-17) and fasten with 1-inch box nails driven through both sides as in Fig. 9-16. Clip off the projecting ends of the nails to within 1/8 inch of the sides and clinch by holding an iron on the nailhead side and bend by pounding over the nail on the other side. After the glue dries, trim all edges evenly and sand smooth, taking care to round the edges of all corners.

Make the pontoon outrigger, upright, and support (Figs. 9-16B and 9-16C) and fasten to the pontoon with glue and 2-inch #8 flat head screws. Reinforce with 3/4-inch triangular glue blocks glued and nailed to the support, upright, and pontoon top as in Fig. 9-16D.

To make the pontoon watertight, first cover the entire pontoon with one coat of fiberglass resin and then apply 2-inch wide fiberglass tape to all pontoon seams and saturate the tape with resin. After the resin has hardened, sand smooth and finish with two coats of enamel undercoater followed with two coats of marine enamel of the desired color. After the outrigger has been painted, fasten it to the canoe with two 1/4-inch bolts bent to a J-shape as shown in Fig. 9-16E.

Click HERE for materials list for outrigger and Pontoon