Has anyone out there had any first hand experience at making a carbon fiber cloth laminate canoe or kayak? I read a book about using Kevlar, but I also have some carbon material that I would like to use on my next boat in order to stiffen it up a bit, while keeping it very light.
Any ideas would be welcome.
Thanks,
Neal
Some Experience
It works pretty well to place the stiff, compression resistant, carbon in the outer layers to replace glass, and use high tensile strength Kevlar/Spectra/Vectrane for inner layers.
The carbon should be protected with a gel coat or a thin 2 oz glass skin coat.
carbon fiber
It’s pretty easy to add weight using carbon fiber. Unless you’re vacuum bagging it, it’s very difficult to tell when it’s wet with resin. It’s black and shiny dry and it’s black and shiny wet. Having a resin rich layup will likely decrease the strength as well as add weight.
Cool stuff to play with regardless, cept for the price.
I think that’s mainly true when you are
laying up a whole boat. When wetting out small patches of carbon fiber, I find it easy to judge when it’s wet out. One cue is that the weave remains prominent, though wet.
Someone with experience laying up glass boats without bagging should develop the style to graduate to carbon and Kevlar without floating the layers in a sea of resin.
carbon fiber lamination
Thanks for the information. If I understand right, it should look like glass when it is fully wet out, but not floating in the resin by still being able to see the weave as very prominent.
Plans are to use 5.0 Kevlar then 5.0 Carbon protected with an outer layer of thin glass.
I also have some 1.8 oz Kevlar which I could use as the outer layer. It wouldn’t be as nice looking as the black, but it would certainly be much more scratch resistant. Any preferences if you had to make the choice and you already had the material available?
Thanks again,
Neal
Carbon shouldn’t float on the resin,
in spite of the fact that it is a light cloth. Polypropelene will float in resin. When you lay up carbon, it will darken with resin when viewed in good light. Your best preparation is to do some small-scale practice layups on an expendable or waxed surface.
question
– Last Updated: Apr-03-09 11:51 AM EST –
are you talking about making a canoe out of solid laminate on a male mold? Putting kevlar on the outside will leave a fuzzy hard to repair surface. You'd be better off using s-glass on the outside for compression resistance, durability and repairability.
For a given amount of rigidity you could make a lighter canoe with a foam core and s-glass than a solid canoe out of carbon/kevlar.
Quite true, but some designs, those
with relatively deep, round arch in the bottom, may be pretty stiff without foam. Other designs with a very flattish arch may require foam to be stiff.
If he’s building on a male mold, a foam layer or things like Spheretex ribs may be difficult or impossible.
actually, I am building a racing pirogue
if you have ever heard of such a thing. We race these things in South Louisiana. It’s a 22 ft. long 19 inch beam boat built more like a kayak than a canoe. Cockpit is open more like a sit on top kayak.It has a very low profile to prevent wind problems.
I am using a male mold which is actually one of my old boats which was originally made with okume and glass that I have already waxed.
I think that I will experiment with two different designs: one with kevlar and S-glass and the second with carbon and S-glass. I can reinforce accordingly since the decks will be covered with bulheads as needed and lay increased inner layers in the cockpit area if needed.I could also use foam cored ribs in that area if necessary.
Anything else that I should think of?
Thanks again,
Neal
Just remember, the Kevlar goes inside.
It’s not rational to put Kevlar on the outside. Carbon makes a good outside cloth if wear is not a problem. S-glass is a hard, slow wearing cloth that is not as rigid as carbon, but is tougher. The old formula for whitewater boats was S/S/K/K, indicating the order of layers from outside to inside. I have a slalom boat that is S/S/C/C, and it is extremely rigid. However, if it ever takes a major shot, it will prove to be brittle.
I’ve paddled in LA some, and I imagine that you will not need to allow for major blows to your boat. I would still recommend at least one outside S-glass layer for wear. Then you can go with carbon layers. Not sure if you need Kevlar.
Carbon/Carbon
– Last Updated: Apr-06-09 8:52 AM EST –
Why even bother with S-Glass and/or Kevlar. A Carbon/Carbon hull would be stiffer and lighter: that is what you should be looking for, for racing purposes and for a 22 feet long boat...
...I doubt that in southern Louisiana you would doing a lot of white water :-)
Kevlar inside/outside
– Last Updated: Apr-06-09 9:38 AM EST –
My Nelo ICF ruled K-1, brings Kevlar inside/carbon outside.
However, I have seen quite a few racing/marathon hull the other way around: kevlar outside/carbon inside -mostly to reduce heat -kevlar (yellow) tends to absorb quite bit less heat than carbon (black). These boats are mostly coming from SA. On the other hand, I have a surfski with carbon inside/foam core/hybrid carbon/kevlar outside (green) which absorb a lot of more heat than my outside carbon K-1. To the point that it could burn your hands in summer time. After the fact, I learned that some green colors can absorb more heat than black :(
Carbon/Kevlar:
Something to take into account, Kevlar flex too much and carbon flex too little -when you have a nice hit, Kevlar would flex to the point where the carbon outside layer would break. Yes, you might paddle back home, but the boat is broken.
I have not found the benefit of my Marathon Nelo Carbon/Kevlar beside of only weighting 17.5lbs. I would be happier with two layers of carbon at the same boat weight.
Just a few thoughts from an exclusive racing point of view...
Note, this boat could be painted, but you would end up adding quite a bit of weight!
I think you’re right about your Nelo.
In the whitewater paddling and racing world, they contrive to put something on the outside that has good compression strength, resistance to scratching, and does not fuzz when worn. This often ends up being S-glass. Carbon may be the next layer in, or in my 22 pound slalom c-1, the layup from outside in is S/S/C/C. Has been so stiff it hasn’t broken, but some day it will take a major hit and crack catastrophically.
Worth considering if they do not
specify a minimum weight. Seems like the original poster is going to have to use foam sandwich or add ribs later to keep a flat bottom shaped the way intended. With the male mold approach, might have to use ribs or thwart-to-keel support after the hull is free of the male mold.
Dark color
if your concerned about the black of the carbon absorbing a lot of heat, couldn’t you “glass” a layer of light colored nylon fabric or similar light weight and light colored synthetic cloth over the outside?