Building a Peterborough Canoe

ETCHEMIN – Algonquin word meaning: Canoe Man

Chris has always been attracted to watercraft. For several years he enjoyed a sailboat. His backyard hosts a composite kayak. He has collected several books which outline the construction of wood strip canoes. It may have happened when he moved into his Medford home. His canoe books resurfaced.

            One day Chris brought four canoe books to the house and asked me to look through them. His idea was that we should select a particular canoe model and then build it. I did read each of the books and I found a strip canoe model which I thought would be an easily handled two man lake canoe. He agreed with the selection. The situation was this: Chris has a full time job, his garage has limited space, and he doesn’t have some of the tools to do the build. However, I am retired, I have adequate garage space, and I have all the tools necessary to complete a build.

            So, it was decided. I would build a strip canoe, with Chris’ assistance. The model I chose is the Peterborough. The construction parameters of the Peterborough are presented in the book Canoecraft, by Moores and Mohr. Virtually all canoe

designs have evolved from Canadian styles. The Peterborough is a direct descendant of the first “white man’s canoe” crated by John Stephenson 125 years ago, it is one of the main models built in the original cedarstrip technique. Its narrow beam and shallow arch hull make it ideal for general-purpose paddling and light tripping.

            The first thing which had to be done was to build the mould. The mould consists of 14 stations, plus stems at each end, which are fastened to what is called a “strong back”. The stations are made by mapping their hull shape dimension onto large graph paper and then transferring the pattern to plywood, or particle board. The strong back is constructed from two 2”x10” boards, each 16’ long. The strong back needs to present a very flat surface onto to which the stations are mounted. Construction of the mould was completed by mid-January, 2018.

            Typically, a strip canoe is assembled with 1/4”x3/4” clear strips of Western Red Cedar, or

Redwood. The Peterborough is 15’9” long. Strips which are laid near the shear line will measure a little more than 16’ in length. This is because of the arched shape of the hull. I chose Western Red Cedar. The picking was slim at this time of the year, but I found a lumber yard which had a selection of 18’ long timbers to choose from. The board foot calculations of the amount of timber needed meant that I had to buy four 2”x6” lengths. In order to carry these pieces of lumber home, I had to create a way to safely secure them to the pickup. I came up with what I have called the “Lumber Buddy”. When the lumber yardman saw how I secured the lengths with the Lumber Buddy he was impressed, and he said that I ought to patent the design. Inquiring minds can find Lumber Buddy on my blog site: rfdblog.blogspot.com.

           Once home, the cedar boards needed to be ripped into 5/16”x2” strips. These strips then needed to be planned to a finished thickness of 1/4”. After sizing, the 2” strips needed to be ripped once again into 3/4” wide strips. The finished 1/4”x3/4” strips now had flat edges. When building with 90 degree edges, you are left with large angle gaps between each strip. This is because the hull shape is curved. The gaps would need to be filled and sanded. A preferable edge shape is to use strips with a bead on one edge, and a cove on the other.. This allows you to form a wood-to-wood ball joint. The initial strip has a cove presented to the second piece. The second piece has a curved, ball, edge which fits snugly into the lower cove. The bead and cove approach permits contouring without creating gaps between any two strips.

            The bead and cove modifications to each strip meant I needed to do some creating. I didn’t have a router table. So, I built one which was tailor-made to create the precision bead on each strip, and then to change bits and re-router each strip to cut the cove. The 1/4” bead and cove bits were a special order made through a local machine shop.    

            The weather in January is predictable. It will rain. Because of the length of the strips, all of the ripping, planning, and routering had to be done outside of the garage. And, the machine work had to be done while weather permitted. Most of the prep work I was able to do by myself. Chris helped as often as he could. The strips were prepared and they were stored safely in the garage. Whew! That was a lot of hurry-up work.

            Anne and I were getting ready to leave on our “2018 Winter Get-Away” in the RV. I had

enough time available to put the first two strips on each side near the shear line. The mould is constructed on the strong back such that one is building the canoe upside down. I demonstrated to Chris the technique to use when adding strips to each side. I suggested to him that if he budgeted time each day to add but one strip, then the canoe would be formed by the time Anne and I returned.

            The two and half month get-away was a fantastic adventure. We returned on April 1^st. Due to other factors, the return to canoe building was put off for a few weeks. Resuming where I had left off the hull got finished within a couple of weeks.

            The convex outer hull needed to be dressed until it was baby bottom smooth. There were inevitable spots which required a dab of wood filler. The entire hull needed to be sanded with 80 grip paper. That was then followed up with120 grit, and finished with 220 grit paper. I have never sand so much in my life; and I was just beginning.

            When smoothness was achieved, the outer hull would receive a layer of 6# fiberglass. The glass would be applied using epoxy resin. I had earlier ordered a shipment of the necessary length of

fiberglass. It had arrived. Chris used copious amounts of epoxy when he was building Alpaca guitars. Not knowing how he may be involved with his Alpaca company in Medford, Chris shipped his stock of resins and hardeners when the family moved west. We were gifted with adequate epoxy stock.

            Epoxy resin has no affinity to vertical surfaces. Applying the resin to the fiberglass was straight forward; dribble some on, let it soak through the glass, roller it out, and then squeegee off any excesses. The pot life, or the time the resin can be worked is about half an hour. The resin becomes tack free in about 4 hours. After that time, and for about 4 more hours, additional resin can be applied with assurance that it will bond molecularly with the previous application. Beyond about 8 hours, the layer of resin needs to be sanded to ensure a mechanical bond with the next layer.

            The first application of resin is sufficient to bond the fiberglass to the wood hull. There isn’t

sufficient resin in the first coating to cover all of the glass weaving so a second, and often a third coating of resin must be applied. This will achieve a clear, fabric invisible finish. That is the goal.

            Until the resin becomes tack free it will seek lowest potential energy; said another way, the stuff runs. Squeegee all you want to remove any excess resin, there is still a way for it to form a dribble. At tack free the runs have firmed sufficient to make them un-squeegee able. This means that the next coating will have to wait until the last coat has been sanded to remove the lumps.

            Sanding is the primary avocation when building a strip canoe. I burned up one orbital sander and needed to visit Lowes to select a replacement. The process is accepted and the results are truly a reward. With the outside of the hull finished, it was time to remove the hull from its mould. I first built a couple of sling stands to hold the canoe. I unscrewed the stations from the strong back and two of us then flipped the canoe right side up and placed it on the slings. Then I began removing the mould stations.

            Looking at the completed shape for the first time made me realize how amazing it was to have

gone from the crude, shapeless stations on the mould to what had become a wonderfully styled canoe. There was to be much more sanding to come. The outer hull is a convex surface. As such, it had no places where the orbital sander could get jammed. Hello, concave. Sanding the inside of the hull is a much more difficult task.

            I carefully worked through 80 grit sanding paper to 220 grit papers. The inside of the hull was smooth enough to fiberglass. Draping the long fiberglass cloth onto the outer hull had been easy. You carefully rolled it out and then you draped it to contour with the hull. That cannot be done with the convex inner hull. The glass fabric snagged at every opportunity. The fiberglass had to be carefully lifted and dropped to achieve the best fit. A few darts needed to be

snipped into the fabric as it was fitted into the tight space of the stems at the bow and stern. I used a soft rag to smooth the fabric to the hull’s surface. Clothes hanger clips were used to secure the positioned fiberglass to the shear line.

            Appling the initial wetting coat of epoxy to the inner hull was a nightmare come true. As with the outer hull, I dribbled resin on, spread it out, let it soak in, and then I squeegeed and rolled the glass. Unlike when glassing the outer hull, air had no place to escape. The squeegee and roller process aided in bringing captured air to the surface. I did the process as best as I could. I then cleaned the tools and removed my gloves and apron. Now, I waited.

            I was shocked when I returned to the garage a few hours later. I had left the fiberglass in a bubble free state. However, I had glassed the canoe early in the morning. As the hours past, the ambient temperature rose. This created expansion of un-noticed air pockets and of the natural out-gassing of the wood as it warmed. The result: lots of bubbles, tiny bubbles; and no wine.

The surfaces of the bubbles were firm enough so they could not be coaxed into sticking back

to the wood. I got up the next morning, loaded 80 grit paper onto my new orbital sander, and I began removing bubbles. Along with bubble removal, I was tasked with dribble removal duty.

Thank goodness the inner hull does not need to be brought to the shiny smooth, low resistant glossiness of that of the water contacting outer hull. It did, however, need to have at least a second coating of resin. This coating would fill in some of the fabric weave exposure, and it would fill in the spots where I had removed the bubble caps. Oops, I forgot to mention that the second coat of resin would also leave a ton of dribbles on the inner side walls.

The shear line was trimmed at the bow and stern to give the canoe a pleasant raised stem look. Once that was done, it was time to begin attaching the inner and outer gunnels. I had chosen mahogany to make the gunnels from. Because of the significant curving required to follow the new shear line, I had to prepare the mahogany in strips. I would then glue and laminate the strips to form the compound curves at each stem.

I chose mahogany to also use for the seat frames. I had made the frames during down times in the glassing process. There are many different ways a seat can be built as far as covering. Besides epoxy resin, Chris brought with him from Vermont a large amount of paracord. This cord had been used to craft straps for the Alpaca guitars. So, supply met demand. I patiently wove paracord to make a very firm, but comfortable seat. A seat was made for bow and stern positions.

Also, during epoxy curing times, I made two paddles. I made the blades of each paddle out of leftover cedar strips. I then made the handles from hickory. The blades were given a layer of fiberglass on each surface and sanded smooth. I fashioned handle grips from scraps of Western Australian Eucalyptus. The paddles would be strong and comfortable to use.

I used every C-clamp I could find to attach the outer gunnel to 1/4” below the shear line. With the shape clamped on, I then drilled pilot holes and drove screws through the mahogany and into the glassed hull. One side of the hull at a time, the outer gunnel was laminated and in place. With the screws holding the outer gunnels to the hull I could now reuse the C-clamps to fasten and laminate the inner gunnel.

The inner and outer gunnels were in place. I replaced each screw holding the outer gunnel with an oak dowel plug. I carefully drilled the dowel size hole half way through the inner gunnel at

each screw position. Tightbond Ultimate wood glue was used to secure the inner and outer gunnels through the canoe’s hull. After 24 hours of cure time for the glue, I removed the C-clamps.

When the gunnel laminate was clamped 1/4” below the shear line it created a very smooth curve. That curve’s fineness could not be created by trying to saw the shear line beforehand. Now that the gunnels were in place, it was an easy process to use the orbital sander to bring the shear line down to the surface of the gunnel. A couple of coats of epoxy sealed the wood of the gunnels and produced a smooth gripping surface.

At least one thwart is used in the strip canoe. The thwart is positioned at the center of the hull. It is mounted to the underside of the inner gunnel. The thwart ties the hull at its middle. This piece of wood also is used as a handhold and as a means of hoisting the canoe overhead for short overland passages. The thwart is made of hickory. I fashioned it so it could fit behind the neck when carried.

All of the while I stewed about how to suspend the two seats. For the sternman’s paddling reach and efficiency, the stern seat is placed as far back as 36” from the stem. This distance still provided enough hull width for the seat. When the seat is hung at least 8” high it will permit the paddler to put his feet under the seat. This seated position allows greater power to be put into each paddle stroke. Also, the lower the seat is will provide a lower center of gravity for the canoe, and thus greater stability.

Most strip canoe builders seem to use something like a long carriage bolt to hang the seats from the inner gunnel. The inner gunnel of this canoe is only 1/2” thick. I didn’t feel a carriage bolt would work well. I decided on a method which hadn’t been written about. I used some of the same paracord I had used to weave the seat to suspend the seats by their four corner stubs. This meant drilling 1/8^th inch holes in the inner gunnel mahogany. I also drilled holes in the seat corner stubs. The seats were tied at the stubs and they hung at the desired 8” height. Hopefully, the seat problem is solved. As a serendipitous plus, the seats can be quickly removed or their heights altered. Why? I don’t know.

The last thing I needed to do was fashion a hook on one end, call it the bow, so the canoe can be tied when at shore. I wanted to avoid using non-brass or non-copper fixtures on the canoe. I experimented with a few designs before I settled on a hammered copper plate with a flat brass strip, curved at the stem and bolted through the small end deck wood. I used a weak acid solution to clean the two pieces and then I sprayed each with clear enamel. This, I hope, will maintain the bright copper shine.

The cedar wood strip canoe is finished. The last thing to do is to prepare a vehicle to roof-top carry the work. The Vanaroo already had a large roof rack. I bought several lengths of pipe, anti-freeze foam to cut and tie wrap to the rack. For good padding, I used double layers of the foam. 

Loading the canoe is a two person task. The canoe is hoisted to height, its gunnel pushed against the roof rack, and then it is rolled to an upside down position on the rack. The only part of the canoe which contacts the rack is the gunnel at the 36” seat position near each end. Two lengths of soft rope snug the bow and stern into their foam pads. Now, I need to gas up the van and decide which nearby lake will host the canoe’s maiden voyage.

 A Hopi Indian work might describe the bowman and sternman in the canoe: Chowilawu – joined together by water.