Greetings from Minnesota!

[Mrindy]

Thank you for adding me to the group! I can't believe I've been missing out on this wealth of knowledge for so long. I'm also a canoe enthusiast and typically paddle the local lakes, streams and Mississippi River with a few trips to the BWCA/Quetico a year. I also did a wilderness trip for a month in Atikaki Provincial Park one time. When I used to live and work in Minneapolis, I was fortunate enough to be able to "canute" to work via the city's chain of lakes. It definitely beat sitting in traffic. Last summer, I built my first kevlar canoe which my wife gladly portages in the BWCA. I was pleasantly surprised that it weighed in at 37 lbs - a huge weight savings from our beastly royalex boat!

Well, I think I have the bug and am considering building a carbon fiber canoe this time. It would be longer and sleeker and really only used for non-white water tripping. I've heard that CF is stiffer and fails more catastrophically than kevlar so I'm wondering if anyone has any recommendations for reinforcement? I used foam ribs covered in CF on the last one, but I've seen a lot of folks who have made a complete foam core on this site.

Anyone know the benefits of going with ribs v. foam core? I'm also considering a partial inside bottom layer of kevlar between carbon ribs en lieu of a complete core. Any advice or personal experience would be welcomed

Thanks again for adding me, and looking forward to learning from the hive's wisdom!

-Mike

 

[Alan Gage]

Welcome aboard! Great to have another builder, especially a semi-local one.

That's a great picture of your wife. Standing in the mud, in a rain storm, carrying a canoe, and a big smile on her face......Does she have any sisters?

Gotta head out for work. Will talk more about canoe building later.

Alan

 

[yellowcanoe]

Carbon fiber is not brittle and does not fail catastrophically but is not used alone in canoes. Its usually paired with Kevlar as both have different flexing properties one does better under tension and the other under compression
I have several canoes of carbon/kevlar that have seen wilderness trips ( long solos ) in Woodland Caribou and Temagami and many other places and weighing in at 23-31 lbs for a 15 foot solo are quite easy to carry. I did not build them. None have foam cores.
Foam cores tend to flatten the bottom even when they are heated. Mass builders use ovens to shape the foam.. My solos have a pronounced round bottom so foam core wont work and the builders do not use them. Ribs dont require as much shaping and the spaces between ribs more flexible.

My solos have several blankets of both kevlar and carbon fiber as well as bottom footballs of a couple of layers.. But they are still light as resin is vacuum infused.. not vacuum extracted. That machinery is soo expensive though maybe some of you builders have made DIY versions.

My Colden Dragon Fly ( a WW canoe) is carbon fiber/ kevlar/ and fiberglass in the high wear areas ( stems) its got 38 pieces of fabric and wound up because of its robust construction at 38 lbs. which is a lot for a sub 15 foot canoe.

To build your own Kevlar canoe is quite an undertaking.. Congratulations!

 

[Muskrat]

Welcome aboard.

Regarding ribs v core, eliminating variables like core material and thickness, a full core will be stiffer than ribs. If stiffness is the goal for flatwater efficiency then a full core is the way to go. A hull with ribs will be more flexible therefore more forgiving under impact. Ribs are easier to repair than a full core. When using ribs the thinnest core possible should be used in my opinion. This reduces the so called stress riser, and makes for a more homogenous hull flexibility.

 

[Mrindy]

Thanks for the welcome! That all makes good sense - I didn't even think about how the foam core could warp the bottom of the hull. If it's a CF layup, you'd think stiffness wouldn't be as much of a concern as flexibility over hidden rocks or occasional beaver dams, which a layer of Kevlar may help with as well. I used 1/2 in (don't shoot me!) pink panther style foam the last time. Any other economical choices or thicknesses recommended?

 

[Muskrat]

I like Lantor coremat. I've used 4mm in the past. It is easy to shape to the hull. It does soak up resin so it's heavier than foam, but I feel it becomes a structural part of the laminate, not just a core. Tradeoffs.

Stripperguy uses divinycell 4 lb density I think. Check out his thread on the carbon fiber Kite he is building. We discussed both materials there.

Edit: we all use what we like. I haven't used the pink foam for ribs. That's what was suggested in Moran's book which is how I got started, and I'm assuming you did too. There are better materials, but it's still perfectly acceptable. I didn't come to this theory of thin ribs overnight.

 

[BWCA66]

Hey, welcome - it's always nice to see someone else from MN. In addition to mixing carbon with something else it's also harder to get the carbon weave laid out to look nice. It is more "pliable" for lack of a better word so laying it down and getting a good look takes more work than Kevlar, IMO. Still structurally sound even if it doesn't look perfect.

 

[Jim Dodd]

Throwing out another Welcome !

Also throwing out another option for a core. 1/8" Western Red Cedar. It is effective, and cheaper than the others. More labor involved.

I built mine on my forms. But beings there is no stress on the strips, I think I could have eliminated the staples, and just edge glued the 1/8" strips together, and held in place with just tape.
The beauty of this method, was it is in the same shape as the hull. I simply mixed 18 oz of resin, added some filler, and spread inside the hull.
I immediately laid in the insert. Covered with plastic, and poured in sand, as weight. I supported my hull, so the weight of the sand wouldn't collapse the hull. I made that mistake ONCE !

The insert was light, and with a 6 oz layer of E-glass over the top, was quite stiff.

Food for thought !

Jim

 

[Marten]

Welcome, I am not a canoe builder but a month in Atikaki got my attention. Just getting started exploring that park.

 

[stripperguy]

Welcome Mrindy and your bride!! I did use 4 lb/cu ft Divinycell foam, 1/8" thick as a core stiffener.
I would avoid using cheap materials for cores, obtain good quality materials that are made to be used as structural elements. After all, the cost differential will be less than $100. Compared to how much you would spend on a production boat, that's peanuts!!
My carbon copy Kite has 2 layers of 5.9 oz carbon and 2 layers of 6 oz glass, it's 14'8" long and I'm on track for (fingers crossed here) 26 lbs when finished. When I popped it off of the plug, it was all kinds of flexible in the bottom.
After adding a bit of 1/8 foam and some carbon over that, well... take a look. Do note that I have no gunnels or thwarts. View attachment UO78kkV-3oJ1_ZYJJ4OgODUaSnuKVZZ4uSyChuyW_lG9p3LkpVc-ohIskRrC0gq6-nflSz6P3OHHV8UHgSm7sj_1ugiYyc1bP6kF

 

[Muskrat]

Yeah, but did you jump on it?

 

[stripperguy]

Yeah, but did you jump on it?

That would be negatory...

 

[Jim Dodd]

Do shy away from Cheap Pink foam !

Been there, done that !

Jim

 

[Mrindy]

Thanks everyone, that definitely gives me a lot to chew on and it's cool to see that there's more than one way to skin a cat, er hull. Very creative options.

Marten - I'm trying to remember the lake we put in at but the halfway point was Lake Sasaginnigak and we then took the Bloodvein down to Lake Winnipeg. Absolutely stunning landscape and it felt really remote. You Canadians are spoiled!

 

[martin2007]

Mike, like Marten, that one-month trip in Atikaki caught my attention! I'm planning on doing a 3-week Bloodvein trip this summer going in either at Red Lake, Woodland Caribou Provincial Park, or at Wallace in Atikaki. Marten with an "e" is from south of the border, and he's travelled extensively in, and posted a lot about WCPP. I'm Martin with an "i" from the southwestern Ontario flatlands. It's really easy to tell the difference. Marten on his videos has a distinct accent, whereas, of course, as a Canadian, I have no accent at all. Welcome!

 

[Marten]

I have been studying maps all winter so when you say Sasaginnigak Lake was the halfway point I know your route from the north probably is not used very much. We plan to fly to Sasaginnigak lake and explore routes from there. The Sasaginnigak River will be in the future as will the Leyond loop back to the Bloodvein. So many possibilities and so little current information available.