This is how to build a DIY cedar strip canoe

2022-12-02 20:21:57 By : Mr. Henghai TOMKING

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I love the adventure and experience of canoe camping. Packing food and camping gear into a canoe and paddling to a wilderness campsite. I’ve taken many week long trips into Canada’s Quetico Provincial Park which is large wilderness area with many lakes connected by portage trails. No motors are allowed in the park, fishing is great and the solitude and scenery become addicting. I had usually rented Kevlar canoes from a local outfitter but I thought I would enjoy the challenge and satisfaction of building my own boat and using it to make a trip.

I originally thought I’d try to build a kevlar canoe but I liked the looks of the cedar canoe so that was my choice. The final cost of materials and tools probably ended up higher than the cost of just purchasing a used or lower end canoe, but the satisfaction from using my canoe is worth it.

The materials needed are: cedar planking you can rip your own from 3/4 wide boards or purchase it already cut and milled, hardwood (preferred) for making the seats, stems, gunnels and decks, woven 6 ounce fiberglass cloth, epoxy resin, and hardener, wood glue, staples, masking tape, packing tape, strapping or caning for the seats, marine varnish, stainless or brass bolts for the seats, stainless or brass wood screws.

The tools needed are: a table saw or circular saw with a jig and a thin kerf saw blade(if cutting your own strips), a router table with a ¼ in. bead and cove bit (if using bead and cove strips), staple gun, block plane, paint scraper, lots and lots of sandpaper, sharp knife, random orbital sander, spoke shave (nice to have), drill, lots and lots of C-Clamps, homemade steam box, plastic spreaders and chip brushes for the epoxy and varnish, disposable latex or plastic gloves.

What follows is a very general description of how I built my cedar strip canoe. If you’d like to try your hand at this project I highly recommend purchasing detailed plans, which will clearly guide you through the detailed process of building your own cedar strip canoe.

Read books about cedar strip construction techniques. Canoe Craft by Ted Moores, Kayak Craft by Ted Moores, Building a Strip Canoe by Gil Gilpatrick. I read Canoe Craft twice before I started the project. Also, visit www.bearmountainboats.com for lots of valuable information.

Determine what the boat will be used for, a canoe for the cottage, a canoe for camping and tripping, or a work of art just to look at hanging in the garage. Choose a design that is practical but also pleasing to your eye. Other things to consider are length, weight, stability (some designs may require an experienced paddler), load carrying capacity, symmetry, speed, and last but not least ease of construction. A design with a high bow and stern may require more effort to bend wood for the stems and one where the hull wraps around the paddler more sharply (called tumblehome) can be more difficult to strip.

These can be purchased from Bear Mountain, Chesapeake Light craft (www.clcboats.com) or a number of other sources. They can also be created from tables of offsets, using a process called lofting. The books mentioned above contain offset tables for several designs. I purchased plans for my canoe and lofted them for my kayak from tables in Kayak Craft. If you purchase plans you can expect a drawing with cross-sectional hull outlines and stem form outlines that can be traced to make the molds. Other than a condensed instruction manual covering the build process don’t expect too much. Follow the books you read.

A sturdy, level, long thin table needs to be built on which the canoe can be assembled. This is called a strong back. Attached to it are 1×1 mold station blocks spaced at typically 12-inch intervals. The molds (or forms) are then attached to the blocks to form a sort of skeleton onto which the strips are temporarily attached and glued together.

The outlines of the hull cross sections are drawn on sheets of plywood, particle board or MDF. They can be traced using carbon paper between the plan and the board. They need to include a pedestal feature so that the forms are held above the strong back an appropriate distance. They end up having a mushroom-shaped profile. Alternately a separate piece of wood can be attached.

The forms are attached to the station blocks on the strong back with drywall screws, taking care to line up the centerline of the forms with the centerline of the strong back. A string stretched from the bow to the stern stem forms will help with alignment. Once all the forms are attached, eyeball the shape from each end looking for forms that are off a little. A long thin strip of wood held against the edge of the forms and slid up and down along the hull can also help to identify forms that need correction. Small shims are used for minor adjustments.

The strips will be glued along their edges and stapled to the forms. Some protection on the forms is needed to keep dripping glue from permanently sticking the hull to the forms. Edges of all the forms should be covered including the stem molds. Plastic packaging tape works well for this.

Use the table saw with feather boards clamped to the guide and table to keep the strip thickness uniform. A circular saw with a guide jig for cutting the strips is shown in the photo. Make a few test cuts and adjust your set up. Using a thin kerf blade like the Diablo, cut more than enough strips since some will break or have large knots or other problems. They do not need to be the total length of the boat, they can be scarf jointed or butt jointed on the hull. The strength of the hull comes from the wood core laminated with fiberglass not from using continuous strips. Measure the circumference of the widest from and divide that number by 1/2 inch to estimate the number of full length strips you will need. Once all the strips are cut use a router table with a ¼” bead and cove bit to mill the edges. Cut the bead first since the cove is more delicate. Once again make some test runs to adjust your set up. Cut shorter strips of softwood and hardwood to laminate for the stems.

The strips used for the stems need to be steamed and clamped onto the stem forms then allowed to dry before gluing them together. Typically 3 or 4 strips are used for each inner and outer stem. I used a 6-foot piece of PVC drain pipe plugged at each end with a piece of wood. One end had a large hole drilled in it. An old percolator style coffee pot on a camp stove was used to create the steam. A short piece of copper pipe replaced the glass bubbler on the coffee pot. The PVC pipe was hung above the stove. The secret to good bending is HOT steam. Use epoxy thickened with sanding dust for glue. When gluing the stem strips together do not glue the inner stem to the outer stem.

Once the glue for the inner stems has firmly set up, they can be attached to the stem mold with a screw through the last hull form into the end of the stem and a screw through the other end of the stem into the stem from.

Now comes the fun part. Start attaching strips to the forms at the part of the form closest to the strong back and work towards the center of the hull. Attach with cove side up to hold a bead of glue. Glue and staple the ends of the strip to the stems, allowing the strip to run past the stem a little. Press the bead of next strip firmly into the cove of the previous strip and staple through both strips into the form. About 3 or 4 strips per side can be attached. Let the glue set before attaching more. Where the strips seem to pull apart between the forms, masking tape can be used to hold them together. Once the hull is stripped up to the flatter bottom section the strips will have to cut and fitted neatly together.

Once the hull is completely stripped it is time to trim the strips flush with the bow and stern stems. The outer stem is then mortised into the hull bottom and glued to the inner stem with thickened epoxy. Screws coated with wax are used to hold the outer stem in place. They will be removed when the glue sets and the holes will be plugged.

Now all the staples are pulled, being careful not to dent the soft cedar. If a few staples are forgotten they will be found in the next step for sure.

The joint where strips meet at curves in the hull is a little squared off. These joints need to be planed to make the hull smooth. The hull can then be sanded with coarse, medium and then fine sandpaper to achieve a smooth or “fair” hull. The Random Orbital Sander works well for this step. Sanding seems like an endless activity, you will finally get to a point where you say “Well, I think that is good enough”. Before the final sanding, the hull should be wetted down and allowed to dry to raise the wood grain.

Fiberglass cloth is laid over the hull so that it extends just past the stems, then smoothed with a soft bristle brush. Epoxy resin and hardener are then applied to the cloth in small batches, working from side to side, in about 2 to 3 foot long sections. It is important that the temperature of the workshop is warm enough as that will affect the curing time and the rate of flow. Three coatings of resin/hardener are applied, the first to wet out the cloth and soak into the wood hull, the second to fill the weave of the cloth, the third to finish and protect the cloth. Each coating should carefully squeegeed with a plastic scraper and only applied once the previous coat has become tacky. This step is intimidating but not real difficult if you are careful. Proper mixing of the resin and hardener are very important.

A cradle must be constructed to hold the upright hull. Carpet scraps suspended from brackets attached to the strong back will work. The screws holding the stems to the last form should now be removed and then the hull can be lifted from the forms. It may be necessary to loosen some of the forms and tap them as some glue residue may be holding them to the hull.

Now it is time for more sanding and scraping. Glue beads can be scraped away. Sandpaper wrapped around a plastic bottle will help fit the curves of the hull. Here again, start with coarse and finish with fine and sand until you are done….at least until you don’t want to sand anymore. Just a note, don’t be tempted to use a belt sander, you could eat right through the soft cedar.

Fiberglass cloth is laid inside the hull and held in place with clothes pins, then smoothed with a soft bristle brush. The cloth is just short of the inside stems. Epoxy is applied the same as was done on the exterior. Any runs on either side of the hull can be taken down with a paint scraper once the epoxy has firmed up sufficiently.

Gunnels are long strips of wood which are attached inside and outside to the top edge of the hull to give it rigidity when combined with the thwart. They are typically ¾ in by 7/8 in strips running the entire length of the canoe. Scuppers or slots can be cut into the inside gunnels to allow water drainage when the canoe is turned over. The gunnels can be attached with thickened epoxy and screws or thickened epoxy alone. The decks are then attached between the gunnels at the bow and stern. The thwart is attached between the gunnels in the center of the canoe.

Seat frames are usually made of hardwood. Ash is typical since it is flexible, but other wood varieties will work. The seat pad can be made with chair caning, strapping or webbing, left over cedar strips, or plywood. Caned seats are beautiful but require a little more work. I made seats from polypropylene webbing. The seat frames are hung from the gunnels with long bolts through dowels which act as spacers. Care must be taken to optimally locate the seats for proper trim, so that when loaded, the canoe will not sink more deeply on one end than the other.

Now you have a beautiful shiny new canoe! It is time to get out the sander one more time and make it look dull. Use a 220 grit sandpaper to rough up the surface, both inside and out. Varnish is required over the epoxy to protect it from being degraded by UV radiation in sunlight. The shine will come right back once the varnish is applied.

All of the wood components like the gunnels, seats, decks, thwart need to be sealed with a 50/50 mix of mineral spirits and varnish before final varnish is applied. A minimum of 3 coats of marine varnish needs to be applied. The varnish should have components that block UV light.

Jim Clem is a software electrical engineer who enjoys the outdoors. He likes to challenge himself with creative projects at home. You can find more of his articles on his HubPages profile.