Jim is a retired software/electrical engineer who enjoys the outdoors. He likes to challenge himself with creative projects at home.
Building a Cedar Strip Kayak
I've spent many hours canoe camping and fishing. Sometimes I like to get on the water by myself and sometimes a canoe will suit me just fine. Other times the weather is not suitable for a canoe, too windy or too wavy, or I just want to cruise the waterways a little more efficiently. A kayak can handle a bit of rough water and can cruise along at speeds comparable to a tandem canoe with two paddlers.
So I decided to build a cedar-strip kayak.
My first project was a Bear Mountain design called a Resolute. It is designed for larger paddlers and is very stable and has lots of cargo space. Even though I was a smaller paddler, I still decided to build this design because I wanted something I could load up with enough gear for a one-week kayak camping adventure.
I built this kayak and took it on a one-week camping/paddling trip in Canada's Quetico Provincial Park, as well as several day trips in recent years. It is enjoyable to paddle and handles small waves just fine. The weight is not too bad and is comparable to non-ultra-light commercial designs. It weighs in at about 60 lbs, is 16 ft. 3 inches long, and has a 25.5-inch-wide hull.
Recently I decided that it would be nice to have another kayak, perhaps a little slimmer, lighter, and faster. I decided to build the Bear Mountain Endeavour design. It has a length of 17ft. and a width of 23.5 in. This article describes the construction of this second kayak.
An alternative to strip construction is using plywood panels and stitch-and-glue construction. This method gives you boats somewhat lighter in weight, but I think it is harder and takes longer to use this method when building from scratch. It is more likely better suited for a kit where the panels come pre-cut to the proper dimensions. Strip construction gives more opportunity to customize the look of your boat with colors and patterns in the strips.
Generally, a longer, narrower kayak will be faster, but less stable, and carries less gear, which is a consideration if you plan to use it for overnight trips. If you want a sea kayak, you should look for a design that has a hull 15 to 18 feet long.
Be prepared to answer lots of questions about your hand-built cedar-strip kayak, and get lots of looks and compliments from people you encounter on your paddling adventure.
Books I Read
As before when I built my other boats, I read and re-read Ted Moore's book Kayak Craft. The instructions in this book are very thorough and I would recommend reading it before you begin a project like this. I also read The Strip-Built Sea Kayak: Three Rugged, Beautiful Boats You Can Build by Nick Schade. Although the sleek designs in Schade's book are attractive, I followed Moore's method because it seemed more straightforward.
Lofting Your Plans
You can purchase plans from a few different sources, or you can create your own from tables in the books I mentioned using a process called lofting. This process is time-consuming but can save you some money. You use the dimensions in the table to create outlines of the forms, which are cross-sections of the hull at regular (typically 12-inch) intervals. I drew the shapes by hand onto a couple of pieces of brown craft paper. If you are more technical you could use CAD software and a plotter to print the large drawings. I only created half-hull outlines because the design is symmetrical about a vertical axis.
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Building a Platform
You need a platform or long table on which to build your kayak. I built one 12 inches wide by 16 feet long from a sheet of 3/4" particle board, leaving only a small piece of scrap. I set the table on a pair of sawhorses and attached it to them with pieces of scrap wood. I also added some bracing and legs in the center to provide more support. The table needs to be level and flat.
Cutting the Forms
I transferred the 1/2 hull plan outlines to poster board to make full-size templates which I traced onto thin pieces of wood to make the forms. I could have used particle board, but in this case, I had a mixture of scrap wood from an old desk and other discarded furniture that I disassembled. The forms were then cut out slightly oversized using a jigsaw and their edges were smoothed and trimmed to the outline using a drum sanding bit in my drill press.
Covering the Form Edges
The strips will be glued along their edges and stapled to the forms. The edges of the forms should be protected 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.
Attaching the Forms
I attached the forms to the table on 2X2 station blocks screwed to the table, one every 12 inches. I attached them with screws, using extensions on the deck side of the forms, which holds the forms a few inches above the table. I made the extensions from 3/4-inch-thick scrap wood. Once all the forms are set, they need to be checked and adjusted so their centerlines are lined up. They also may need to be adjusted so that if a strip of wood is laid across them there are no gaps or high spots. The strip should touch all the form edges over the entire shape of the hull.
Milling the Strips
On my first kayak I used some salvaged white pine that was about 130 years old and had very straight grain. On this one, I cut my own strips from cedar purchased at Home Depot. Some of the strips were cut from 5/4 cedar deck planking but this made strips a little wide for my liking.
Use the table saw with feather boards clamped to the guide and table to keep the strip thickness uniform. You can use a circular saw with a guide jig to cut the strips. Make a few test cuts and adjust your setup. 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 form and divide that number by ½ 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.
It is difficult to get perfect strips due to warping and feeding difficulties. If I build another boat I will first purchase a thickness planer. I'll cut the strips extra thick on the table saw then use the planer to make them a uniform thickness.
Laminating the Stems
The strips used for the stems need to be steamed and clamped onto the stem forms and then allowed to dry before gluing them together. Typically three or four 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.
The secret to good bending is HOT steam. I used an old percolator-style coffee pot on a camp stove to create the steam. I replaced the glass bubbler on the coffee pot with a short piece of copper pipe, and hung the PVC pipe above the stove.
Use epoxy thickened with sanding dust for glue. When gluing the stem strips together, do not glue the inner stem to the outer stem.
Attaching the Stems
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 form.
The stems need to be trimmed with a plane so that the ends of the planks rest flat against them. This provides a solid surface for the glue joint.
Attaching the Sheer Clamp
The sheer clamp is a piece of wood about 3/4" X 7/8" that runs the length of the kayak on each side. It is used to hold the bottom half of the hull to the deck. I made mine from yellow pine by ripping 2X4s, but it can be made from cedar or even hardwood. It is attached with screws to notches in the forms. The screws run vertically up into the forms to hold it on while applying strips to the lower hull. It should be covered with plastic packing tape to keep it from becoming glued to the hull. That will come later.
The sheer clamp needs to be cut at an angle on the ends so that it will come together and butt uniformly against the stem on each end. A notch in the bow and stern forms needs to be cut in order to accomplish this.
Stripping the Hull
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 the next strip firmly into the cove of the previous strip and staple through both strips into the form. About three or four strips per side can be attached at a time. 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. You may have to use some creative clamping methods to hold the strips in place, especially where they round the curves in the hull. Once the hull is stripped up to the flatter bottom section the strips will have to cut and fitted neatly together.
Attaching the Outer Stems
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.
The outer stem should be planed and sanded until it is flush with the strips in the hull.
Planing and Sanding
Remove all the staples. The joints where strips meet at curves in the hull are 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.
Applying Exterior Fiberglass to the Lower Hull
Fiberglass cloth is laid over the hull so that it extends just past the stems, then smoothed with a soft bristle brush. I used 6 oz. e-glass for this step. Epoxy resin and hardener is 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, and the third to finish and protect the cloth. Each coating, except the third, should be carefully squeegeed with a plastic scraper and only applied once the previous coat has become tacky.
This step is intimidating, but not really difficult if you are careful. Proper mixing of the resin and hardener is very important.
Stripping the Deck
Once the epoxy on the hull has cured, remove the screws holding the mold extensions to the station blocks. Then flip the hull. I first lifted it off the build table and set it on the floor. Next I made two plywood cradles and screwed them to the station blocks to hold the hull while the deck was being stripped.
First two strips on each side are laid, then clamped and glued to the sheer clamp. Then one strip is placed down the center and attached temporarily to the forms with small finishing nails. The remainder of the strips are placed from the center strip towards the outer edges. Once this is complete, plane and sand as usual.
On the deck I did not use staples. Instead I held the strips in place with L-shaped scraps of wood which were clamped to the forms with C-clamps. Masking tape helps a lot too.
Exterior Fiberglassing the Deck
The same process is followed as with the lower hull. I used 4 oz. e-glass for this. Once the epoxy has cured the excess can be cut off with a utility knife.
Interior Fiberglassing the Lower Hull
Fiberglass cloth is laid inside the hull and held in place with clothes pins, then smoothed with a soft bristle brush. I used 4 oz. s-glass for this. 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.
I also laid 6-inch-wide strips of fiberglass cloth across the floor of the hull about 6 inches apart. They did not span the entire width, but ended just after the hull curves upward. These strips were applied after the first coat of epoxy. The second and final coat was applied over both the base layer of cloth and the added strips.