BWCA Feedback Wanted on Canoe Design Boundary Waters Group Forum: Boat Builders and Repair
Chat Rooms (0 Chatting)  |  Search  |   Login/Join
* BWCA is supported by its audience. When you purchase through links on our site, we may earn an affiliate commission.
Boundary Waters Quetico Forum
   Group Forum: Boat Builders and Repair
      Feedback Wanted on Canoe Design     



member (24)member
05/22/2021 09:03PM  
I've decided I'm going to build another canoe. Before I jump into my first draft of what I'm thinking, I thought I'd give a bit of background explaining what I've built before, what I'm going for, and what my concerns are.

A couple years ago, I built a skin-on-frame version of the Puddle Duck from "Building a Strip Canoe." It turned out okay for having not really built anything before. A year or so later, I finished a 15 foot canoe I (poorly) designed. I'm proud of how it turned out structurally, but its bottom is so round that it can only be paddled kneeling, and even then it's like paddling on a balance beam. Still, I learned a lot about what to keep in mind as I start the drawing process again.

First, I'm not trying to make my own design to save money, so there are no worries there. I enjoy the process of going from drawing to paddling something I laid out and built. Second, I'm planning on building using aramid and possibly carbon with a mix of techniques from "Building your Kevlar Canoe" and "Canoe and Kayak Building the Light and Easy Way."

So, I'm trying to design another canoe (with a lot of help from several books and other resources). My plan is to take the classic Prospector design and make it slightly leaner as a fully solo boat.

With all that in mind, I'm hoping to avoid the mistakes I made with my last build, so I'm hoping anyone here can help advise on major issues I'm overlooking with this first draft. I know there's a lot of wisdom on these boards and appreciate any feedback.

      Print Top Bottom Previous Next
distinguished member(586)distinguished memberdistinguished memberdistinguished memberdistinguished member
05/22/2021 10:59PM  
That is pretty ambitious ! But doable.

If your design has any Tumblehome in it, that can present some challenges.

I've built 4 to date composites, using a canoe as the mold.
Here is another link, to my last. ( they save me a lot of typing) !
member (24)member
05/23/2021 06:19PM  
1JimD: " That is pretty ambitious ! But doable.

If your design has any Tumblehome in it, that can present some challenges.

I've built 4 to date composites, using a canoe as the mold.
Here is another link, to my last. ( they save me a lot of typing) ! "

I've read through that thread a few times, and your Black Pearl has definitely been an inspiration for this project in terms of making it seem realistic to make a composite boat successfully as a one-person project. What a beautiful canoe!

Early on in that thread, I think you wrote that if you could do it again, you might skip the carbon and just go straight Kevlar. Do you still feel that way? I've been looking at aramid, aramid/carbon hybrids, and innegra. I've read that innegra floats on epoxy, but I've also seem some forum posts where people used it in a hand layup for surfboards and paddleboards. Right now I'm thinking about three layers of around 5oz aramid with carbon for the foam ribs and other reinforcement, but I'm so curious about carbon/aramid hybrids and innegra. Any advice on fabrics?

The other thing I'm not sure about yet is whether it's worth it to keep the stems open until after it's off the form or not. If I'm not mistaken, it looks like you sealed them up while still on the forms. Did you have any trouble getting the whole thing off the forms doing that?

Thanks for any advice you've got!
distinguished member(586)distinguished memberdistinguished memberdistinguished memberdistinguished member
05/23/2021 09:51PM  
OK, some insight. Hand laying both carbon, and Kevlar. The difficulty lies in wetting them out, short of Vacuum bagging.

Kevlar is a little easier, at least with the weaves I was using. I'm far from an expert in these lay ups. A little Phone time with the experts at Sweets composites would do you good.

I didn't use foam as you've all ready seen. To me ? it's expensive, and not that readily available. I do like my 1/8" wood inserts , over foam.

I left my ends open, mostly because of the Tumblehome, and lifting the hull from the plug. I know a builder that used a BMB Freedom 17 as a male plug. He was able to lift the hull from the plug, without trouble. So closing the ends, depends on hull shape.

I know S-glass is more expensive than the more common E-glass, Inn my book the best choice. It wets out just like E-glass, but is stiffer, and more abrasion resistant.

I wish I had experience with Innegra . There are some build threads using it, but I want to play with some, before making the Leap.
Go to < Canoetripping.Net> and do a search for Innegra
member (24)member
06/09/2021 06:43PM  
Construction is underway on my skinny, prospector-inspired canoe (The Alfred Packer?). My forms are on the strongback, and I'm in the process of running my cedar strips through the router to bead and cove.

I had the forms printed on 24" x 36" blueprint paper at Office Depot. I cut the forms out from 1/2" particleboard using a jigsaw, because I had a hard time fitting them through the band saw. I took a while to center and mount it all, but the forms are mostly where I want them. One thing I've learned from my past two skin-on-frame builds is that small mistakes compound into large issues as the builds progress, so I've been trying to be as detailed as possible.

I decided not to go with the Moran method (basically making a stripper with pink foam), because I wasn't sure what I'd do with a pink foam mold when I was done and didn't want to deal with the mess of sanding drywall mud. I decided not to go with the method Rizzetta describes in, "Canoe and Kayak Building the Light and Easy Way," which is to build a skin-on-frame boat without the ribs and use it as a mold while still on the forms. My concern with that method is that the strips will telegraph through to the aramid. I'm still using both books for other information and highly recommend them, but decided to go with a cedar strip mold.

With a cedar mold, I'll have the option of finishing it and having a second canoe when I'm done. Maybe I'll give one to my brother, because as my pictures attest, I already have too many canoes. The only downside to doing it this way is the expense of cedar right now. I spent almost $9 a board foot.

My plan is to cover the cedar mold with window shrink film once I've sanded it smooth and then start laying up the aramid. I haven't decided exactly what fabrics I'm going to use and in what order yet but will use aramid for sure.

The next step is to finish the bead and cove on all my strips.

distinguished member(2965)distinguished memberdistinguished memberdistinguished memberdistinguished member
06/09/2021 09:28PM  
I likee!

Standing by.....
distinguished member(586)distinguished memberdistinguished memberdistinguished memberdistinguished member
06/11/2021 03:49AM  
Sound reasoning. The 4 composites I built, were using my strippers as molds.

Good progress !
Watching also !
member (24)member
08/07/2021 05:40PM  
I've been making slow but sure progress over the summer. During June and July I laid and stapled all my strips, and the past week or so I've spent hours filling holes with epoxy and sanding the hull.

While I was laying strips, I tried to do the Gil Gilpatrick stemless method but was cutting the angled strip to match the square strip and not vice-versa. The angled strips were not sitting perfectly, and for a while I was pretty nervous my stems were crooked. However, with a lot of sanding, my stems seem like they're going to be straight enough.

I also struggled to get my strips to lay flat on my forms. I think this may be in part because of the design of the canoe, which has tumblehome at the center but has pretty significant flare at the bow and stern. I resorted to using many more staples than I think is typical, and I used a lot of screws toward the bow and stern. All of the screw holes needed to be filled with epoxy/sawdust and don't look great.

At times through the process of stripping the hull, I wished I'd gone with the quicker method Sam Rizzetta lays out in, "Canoe and Kayak Building the Light and Easy Way," especially since this hull is a spin-off of other designs and isn't at all proven. Nonetheless, I'm proud of the stripped hull I've built, and it's given me a huge appreciation for the perfect, craftsman style canoes built in the style of "Canoecraft." Mine is definitely not perfect and has a lot of places where it's held together by cedar sawdust and epoxy. Overall, stripping the hull was a great learning experience.

For a while, I've been thinking I might just finish the hull as a cedar strip canoe and forgo laminating a second hull on top of the first. Then, I ran across a YouTube video about Lake Constance Canoes in Germany. Lake Constance Canoes is (was? I couldn't find a lot of information about them from after about 2018 or so) building composite hulls from flax fabric, which is what linen is made of. I learned that some luxury car brands are also using natural composites. I did a deep dive on natural fabrics. The DIY surfboard community at had some useful information about linen and hemp, so I did a lot of reading there as well. Finally, I found a bachelor's thesis on natural canoe construction using a hemp/flax hybrid fabric.

Lake Constance Canoes

Luxury car brands using natural composites

I realize Lake Constance Canoes is using a flax fabric specifically made for composites, but it's about $44 a meter, and I could only find a source in the UK. With no real access to natural fabrics designed with lamination in mind, I still wanted to experiment, so I bought six ounce hemp fabric, lightweight linen, and craft store burlap (jute).

I laminated 6" by 6" squares of each fabric with System Three General Purpose Epoxy, plus a rectangle of linen backed by 3/32" basswood. All three squares were failures and cured me of my desire to experiment with natural fabrics. I haven't laminated fiberglass or other typical composite fabrics yet, but it seemed like all of the natural fabrics used a lot of epoxy.

One layer of six ounce hemp was incredibly floppy. The linen was probably too lightweight a fabric to begin with but was also too floppy. I realize most composite canoes are made of multiple layers, but I had a hard time imagining that any amount of layers would yield a stiff enough canoe. Surprisingly, burlap was more stiff than hemp or linen, but it had a lot of issues too. It sucked up resin and distorted when brushing on the resin and squeezing out the excess. It was far stiffer than the hemp or linen when it cured, but was easy to bend and break. Natural composites have been used successfully in canoe-building, but I didn't think I could make it work and won't be going that route.

Like I said earlier, there are a lot of threads on Swaylocks about natural composites.
However, Surfboard makers are laminating over foam the entire length of the board, which of course provides some structure, so I found out it's not a perfect translation to composite canoe building.

The linen over basswood was more interesting. I think linen could be a more natural composite alternative for cedar strip building, but it would cover up the beauty of cedar, and I'd definitely want to test more before I'd go that route. I think it has some promise for the tiny population that wants to build the greenest canoe possible. Durability is definitely an open question.

The idea behind linen, jute, and hemp is that they're more eco-friendly than fiberglass, aramid, or carbon fiber, and I have no doubt that can be true when they work. I've come to think though that the "greenest" canoe, in the words of someone (can't remember who) I came across while researching alternative composite fabrics, is the canoe that lasts the longest.

So, I'm at the point where I should probably decide to laminate a second hull from some combination of aramid and carbon or just finish the cedar strip hull I've started. Cost is a factor, as is garage space and the number of canoes I already have. I'll have to do some thinking and figure out where I want to go. At least I've got options!

Things I'd do differently next time...
-Use spruce or pine to build a plug, since it's a lot cheaper.
-Use hardwood stems and/or make sure to do a precise and accurate job cutting the strips for stemless construction.
-Use a planer on the strips before cutting the bead and cove to reduce the amount of sanding that's necessary.
-Put the cove side up as a natural channel for the wood glue.
-Maintain better attention to detail all around when stripping the canoe.
distinguished member(586)distinguished memberdistinguished memberdistinguished memberdistinguished member
08/07/2021 08:41PM  
In my experience.
Stems are a waste of time !
There is no need to plane strips, if you cut them with a Skilsaw and fence.
a link that shows my methods.
distinguished member(586)distinguished memberdistinguished memberdistinguished memberdistinguished member
08/07/2021 08:57PM  
distinguished member(586)distinguished memberdistinguished memberdistinguished memberdistinguished member
08/07/2021 09:09PM  
Another link to Trimming strip ends, on a Stemless build. This works wether you bead and cove, or not.
I hope this helps !
member (24)member
08/08/2021 10:44AM  
1JimD: " In my experience.
Stems are a waste of time !
There is no need to plane strips, if you cut them with a Skilsaw and fence.
a link that shows my methods. "

I think I agree about the stems, especially with the suggestion to use the alignment strips, but a couple weeks ago I was panicking. My stems sanded up fine, but I'm going to have to borrow the alignment strip idea for sure.

I'm intrigued by the Skilsaw method of cutting strips and will have to give it a go when it comes time to build another boat. I have an underpowered battery circular saw, so I'm wondering whether it will require an upgrade.

Question for you... On your Black Pearl build thread on canoetripping, you wrote that, "I would suggest anyone wanting to try this method, go with a 8 or 9 oz Kevlar, and skip the Carbon fiber. It will keep the cost down, and be just as durable." Do you still feel that way? How many layers do you think you'd need with an 8 or 9 oz Kevlar?

I found this surprisingly cheap 9.15 oz aramid at Composite Envisions. Composite Envisions

I found a few other similar fabrics. Is that close to what you went with for your first composite? I think you wrote though that you'd go with woven over the stitched?

I like the look and stiffness of carbon but am worried about wetting it out properly. But cost is a factor too, and I've found 6 oz satin carbon for roughly $7 a yard cheaper than 6 oz plain weave or satin aramid.

Decisions, decision...
member (24)member
08/08/2021 11:11AM  
Woops, realized I already asked about skipping carbon. Please disregard!
distinguished member(586)distinguished memberdistinguished memberdistinguished memberdistinguished member
08/08/2021 09:35PM  
The Biaxial worries me, that it might be too rough a finish to properly.
My first Kevlar, I used a single layer of Kevlar cloth from Noah's. 9 oz Kevlar. plus a couple of E-glass layers, one outside, and one inside. The foam insert I used was inadequate ( Pink Construction foam) It was also covered with E-glass.

The Kevlar worked fine, but it was only 58" width.

I think there are better layup schedules out there.
The carbon adds stiffness, but little else. I had some issues wetting it out. I would lean more towards Kevlar and S-glass.

Contact Sweets Composites for a lay up combination. They are very helpful.

Full layers, of Kevlar, and S-glass, with either foam, or my favorite, 1/8" thick Cedar insert, and partials layers at strategic points on the hull, will produce an excellent weight to strength ratio for a hull.
The Skilsaw method is a tried and proven method, that I learned from the Minnesota Canoe Assc. Get a saw that is rated for 15 amps, and it won't let you down !
      Print Top Bottom Previous Next