Ooooh, bad news, boys....
Weighed it this morning, 27.5 lb, no hope now, I'll just have to throw it away.
Weighed it this morning, 27.5 lb, no hope now, I'll just have to throw it away.
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Happy Card Playing Day! ♠️♥️♦️♣️🃏
J Winters "Kite" build
- Thread starter stripperguy
- Start date
So you gained 3.5 pounds with the glassing of the inside, that's not a lot of weight. When I get to mine, I'll have to do the same and see how much more the six ounce weighs. In regards to your seat, have you thought about placement yet? The Osprey calls for a sliding seat. I never put a slider in mine, but i played around with placement a fair amount before I settled on something I was comfortable with….If I'm remembering correctly, I think the front of the seat was nine inches back from centre. There were times on trips when I wished I had installed the slider, so that instead of throwing packs around i could have just move forward or back. However, I'll probably stay with a fixed seat this time too.
I'll bring over the dumpster... free of charge!
mem,
When I built my DY, I completely missed with respect to the seat placement, I had to carry an empty water jug with me to trim the hull, if I didn't have much gear with me.
This time, I decided to have an adjustable seat location, but I intensely dislike any arrangement that requires tools or fasteners, tools can be forgotten, and fasteners can be lost in the brush.
In another thread on this forum, davavd was showing how he attached his foot braces using Velcro. BINGO!! I plan to make and install a couple of carbon fiber over foam cleats, and glue on some Velcro. Same for the ends of the seat frame. Doing so also solves the problem of a seat frame being in the way during carrying. And no tools or fasteners! Sounds like win, win, win to me!!
And the weight? I've been beating myself up about it...with the cove and bead strips, I sanded off very little material. Next build, I'll start with a thinner strip. Other than that, this hull design has some tall (for me, anyway) stems and sheer line. Al that extra hull doesn't come for free, right?
I've actually built this as a folding boat, I can fold it at least once. Unfolding it, however...
So, you have a wood and fiberglass boat that weighs less than 30 pounds... and the problem is?
Mem, when solo'ing my chestnut, I take a rope and loop it around a grab thwart at the front, tie it off to the forward pack and the other end of the rope goes on my side of the pack, then I can slide it forward or back as needed without leaving my seat using the rope.
Mem, when solo'ing my chestnut, I take a rope and loop it around a grab thwart at the front, tie it off to the forward pack and the other end of the rope goes on my side of the pack, then I can slide it forward or back as needed without leaving my seat using the rope.
I like that idea, thanks
Mihun,
In my career, I can't miss by 20 or 25%...lives would be lost!! To do my estimates and calculations and miss the mark by this much is a blunder!!
Couple my intellectual failings with my continually shrinking physical manifestations, and I am a total loser...
OK, maybe not a total loser, but I do still enjoy paddling waters that are less travelled, and sometimes that means a carry of 5 miles or so, often without any trail or even a footpath. With a full pack and food for a few days, a 30 lb boat is over my limit.
I do have access to my son's 10 lb Snowshoe, but I am unwilling to trade the poor paddling of a pack boat for the poor carrying of a well designed solo canoe.
Where does that leave me?? Sitting here moaning about a mere 5 lb overage? Well, I suppose so.
The next build will just have to have thinner strips!!
Well, there is a novel concept that some of us have developed over the years…it's called the double carry, or making two trips on the portage. That's why I'm not overly worried about the weight of mine. Anything under 50 lbs is cool, cause I'm going back for a second load. Sometime I even triple carry, especially if I'm packed up for hunting or fishing. One of my friends called it the "sniff the flowers" style, and I am beginning to develop a taste for it.
Not sure lives are at stake here but thinner strips/lighter boat may lead to structural integrity issues.
We always double carry, sometimes one extra trip for one of us and my Kevlar/carbon Swift only weighs 40 pounds. We are succumbing to age and physical limitations. You might want to consider double carries if you still want to be tripping at 70.
We always double carry, sometimes one extra trip for one of us and my Kevlar/carbon Swift only weighs 40 pounds. We are succumbing to age and physical limitations. You might want to consider double carries if you still want to be tripping at 70.
All well and good, but I wouldn't want to do the 5 mile, bushwacking portage that stripperguy described as a double carry on my best day!!
Dave
Dave
Structural integrity can be estimated, calculated, tested and verified before ever stapling on a single strip. Sample panels can be quickly built and tested if I take the time to do so. If...such a big word for only having two letters!!
And double carrying? I really try to avoid that as much as possible...some of my trips would be 15 miles. Can you imagine 3 trips through this stuff??
Or
I had some time this afternoon, after a dental appointment, to mess with the boat.
Quick and dirty, here's the update.
Fututre bulkheads and decks before and after wetting out.
Foam gunnel substrate
Bias woven CF tape, 4" wide laying on gunnel
Wetted out CF gunnel on sample hull section
End view
Another view
Quick and dirty, here's the update.
Fututre bulkheads and decks before and after wetting out.
Foam gunnel substrate
Bias woven CF tape, 4" wide laying on gunnel
Wetted out CF gunnel on sample hull section
End view
Another view
I've been patiently waiting for you to get to the CF gunnels. How do you think they will compare to traditional wood with regards to stiffness and weight? What did you use for foam? did you profile it yourself? Are you planning on forming it in place then taking it off to cleanup?
Boat looks sweet although a little heavy
Nice job, thanks for the education/inspiration.
David
Boat looks sweet although a little heavy
Nice job, thanks for the education/inspiration.David
I've been patiently waiting for you to get to the CF gunnels. How do you think they will compare to traditional wood with regards to stiffness and weight? What did you use for foam? did you profile it yourself? Are you planning on forming it in place then taking it off to cleanup?
Boat looks sweet although a little heavy
David
David,
The foam is cut from some 2" thick insulation made for housing construction. I think it's between 2 and 4 lbs/cu ft. I need to check for sure. This particular piece was just a quick test to see if it would easily shape and to see how well the CF wrapped around the foam. I cut the foam on a band saw, table saw and also used the stationary belt sander, then hand sanded. It took all of 5 minutes! Stiffness is yet to be determined, but a similar approach is used on production hulls. Compared to wood, a CF over foam section should be stiffer and much lighter than a similar geometry wood section. I have a partially finished hot wire foam cutter here at work, I can form the wire to cut nearly any shape that I like. I'll likely hot wire cut the foam to near net shape and size, including the slot that fits over the hull. Then epoxy the foam in place, final shape and smooth the foam. Lastly, I'll laminate the CF over the foam and overlap onto the hull, similar to the test piece in the photos.
I'm looking forward to seeing the gunwales applied as well. I'm not familiar with this at all. How do you think they will hold up to things like car topping? Will you be able to pry off of them with no worries?
mem,
The gunnels better hold up to car topping, otherwise, why bother?? After I test a section, I'll better know how all this will go. SIL makes his parts with up to 4 layers...I'm not willing to do that, based on cost and weight concerns.
Just my 2 cents. My composite gunnels are 3 layers carbon fibre, one layer kevlar, and one layer of fibre glass. I used 1.5" high density styrofoam for a core and cut the strips with a utility knife. The kerf I did with a table saw and epoxied the square piece onto the canoe where it was sanded to shape. The styrofoam is easily sanded, but that is the easy part. On my first canoe I did not tape off the rest of the canoe for the wet out phase and dripped all over the boat. The second attempt was much better as I taped poly inside and out to contain the drips.
Also, the cost of the tape form of carbon fibre is outrageously expensive so I cut strips of cloth instead, which can be done, but is a PITA. However, don't kid yourself with one layer of carbon fibre, it is not sufficient.
Of course, just my opinion.
Also, the cost of the tape form of carbon fibre is outrageously expensive so I cut strips of cloth instead, which can be done, but is a PITA. However, don't kid yourself with one layer of carbon fibre, it is not sufficient.
Of course, just my opinion.
LF...this is exactly the kind of responses I'm looking for, much appreciated. The CF bias woven stuff is about twice the cost of regular CF tape, which you already deemed too expensive!! If I have to (and it seems that I might) build multiple layers, I'll do the underlying layers in less costly material.
And I was just talking to one of my boat buddies about the danger (?) of drips and runs on an otherwise finished hull. Consider me forewarned.
Thanks again!!
I am enjoying this chronology of a build very much. You are really doing a nice job of conveying the nuances of canoe craft. What I like best about boat building is the dream of the tripping that will take place later.
On the tip note, the final layer of the gunnel should be fibre glass tape because you do not want to sand the carbon fibre, and you will be sanding the outer layer because you are an engineer with an eye for detail. (BTW, thanks for posting the cool details of your tests.) Use "frog" tape along with poly to contain the drips and keep a heat gun handy to remove the tape as the epoxy has a habit of hanging on to the edge of the tape.
On a final note, I suppose by now you have come to the conclusion that there is no free lunch when it comes to the weight vs. strength issue concerning canoes. How much weight can you save by making thinner strips? Probably not enough to make it worth while. I could save at the most 10 lbs on my composite canoes, but I am not willing to trip with a boat that might possibly fail while I am out in the wilderness.
On the tip note, the final layer of the gunnel should be fibre glass tape because you do not want to sand the carbon fibre, and you will be sanding the outer layer because you are an engineer with an eye for detail. (BTW, thanks for posting the cool details of your tests.) Use "frog" tape along with poly to contain the drips and keep a heat gun handy to remove the tape as the epoxy has a habit of hanging on to the edge of the tape.
On a final note, I suppose by now you have come to the conclusion that there is no free lunch when it comes to the weight vs. strength issue concerning canoes. How much weight can you save by making thinner strips? Probably not enough to make it worth while. I could save at the most 10 lbs on my composite canoes, but I am not willing to trip with a boat that might possibly fail while I am out in the wilderness.
I'm surprised one layer of CF doesn't give enough stiffness (being so strong in tension). To me that seems to indicate that something is failing in the core, maybe the foam is not good enough in shear and the full loads are not being transferred to the CF. If the core isn't the problem, I'd think making the section more "T" (wider) shape would get your moment of inertia up and be a better trade.
If it is a problem with the core, I'd consider using an extra cedar strip prependicular to the shear and add a little foam under it to form it into a gunnel shape. Then CF over the whole thing. The cedar strip would be better to handle the shear stresses and the CF takes the tensile loads.
David
If it is a problem with the core, I'd consider using an extra cedar strip prependicular to the shear and add a little foam under it to form it into a gunnel shape. Then CF over the whole thing. The cedar strip would be better to handle the shear stresses and the CF takes the tensile loads.
David
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