Strip thickness

[Jon Boy]

Whats the thinnest strips that anyone out there has tried and got away with? Ted Moores recommends 1/4 inch but have people tried anything thinner I was thinking on saving some weight or would this just over complicate my build .Is halving this far too radical an idea ? Would there be any advantage to this or would it just present me with more problems . This will be my first build am I just asking for trouble would the strips break or buckle as they were coaxed into place and would the boat have enough strength when completed ,Im thinking that most of its strength comes from the epoxy resin and cloth sandwiching the wood .
Thanks in advance any suggestions greatly recieved

 

[Todd Bradshaw]

Back when Norm Sims and I built a bunch of strippers we routinely used 3/16" thick strips for most canoes without any problems. I doubt the weight savings amounts to much compared to 1/4" strips, but it can certainly be done and works fine. I know of a kayak builder or two that use 1/8" thick strips, but I'd be leery of trying something as wide as a canoe with them (plus it's a pretty tricky stripping job trying to keep them aligned with no margin for error).

Yes, the strength comes mainly from the fiberglass layers, but the stiffness and shape-holding ability of the hull comes from spreading the inner and outer glass laminations apart (the job of the wooden core between them). A thicker sandwich is stiffer. Since strip construction is somewhat limited in its ability to flex without damage, you generally want to keep them fairly stiff.

The best advice anyone can possibly give you on your first build is to find a good set of directions and follow them to the letter (strip dimensions, cloth weights, etc.). All too often, the reason that first-time builders manage to royally screw up perfectly good boats is because they get too clever and think they have a better idea of how to do something, but no experience to back it up. There will be plenty of opportunities to explore other options on future builds, but first, show yourself and everybody else that you can build a good, sound boat (spoken by a guy who has sawed-up a partially completed experimental boat or two in his day and tossed it in the dumpster...just ask Norm).

 

[Dan Lindberg]

Follow Todd's advice.

Yes, there are folks who build/have built with thinner strips, but it takes more effort and care to keep the strips aligned.
A good compramize is 3/16, that will save you about 5 lbs IIRC.

On my last stripper, I used 3/16 in the bottom, 5/32 in the chine and 1/8 on the sides, it's saved a few more lbs, I can't remember how much off hand. There is more ft^2 on the sides than on the bottom.

If you are mostly concerned about weight, buy or build a all kevlar canoe, check out Moran's book and search the web, there is a guy that has a BB on building them and he has built 4-6 of them.

Dan

 

[Charlie]

There is a book called "Building Your Kevlar Canoe". It's the only volume I've ever seen on the subject. Building in glass/Kevlar looks very demanding because of the detail that must be adhered to in the mold and the tight laminating sequence that requires about three experienced individuals working many continuous hours. Building the mold as portrayed in the book looks so demanding it doesn't seem worthwhile to build one for only one hull.

 

[Dan Lindberg]

I would suggest that whether you're laying up glass or kevlar, except for the cutting of the kevlar, both operations are about the same.
And laying up glass has the same details that have to be watched as kevlar, and these days, with either cloth, you'd probably be using the same resin.

As for the making of the mold, yes, it's some work, but plenty of kevlar canoes have been layed up over other canoes that a mold isn't completely necessary.

Dan

 

[normsims]

Jon,

Remember that you're going to be running a high-speed disc sander over those strips--inside and out--after you have glued them in place. A certain amount of the thickness gets sanded off. I wouldn't recommend thinner strips, especially on the first job, for fear of disasters created during sanding.

Todd's right about cutting up a nearly completed boat because it didn't meet his standards. OK, someone will ask. In the little holes left by the staples, the epoxy showed as green. Little bitty dots that were dark green instead of black. He didn't like that color and the next thing I knew he had cut the bow off the boat with a saber saw. He made it into a wall hanging in the shop. It looked like someone had paddled a beautiful Sitka-spruce racing canoe real hard and rammed it through the wall.

Norm

 

[Todd Bradshaw]

Norm, I was going through my photos the other day and looking at those I took the day I wrestled the big canoe up into the garage loft. I came across this one, which reminded me of something. Then it came to me......... picture below.

If I don't start getting more use out of this one, I'm sorely tempted to cut both ends off and hang them on opposite ends of the garage, which would be so cool that it's almost worth doing. I guess the rest of the boat would have to be made into some sort of really ugly scow.

 

[Mark Neuzil]

I see you guys used the Arthur Heming design in the paint. Can't go wrong with a Canadian painter.

 

[Todd Bradshaw]

Yep. When I first saw that painting on the cover of Eric Morse's book "Fur Trade Canoe Routes of Canada/Then and Now" my first thought was "I want a boat that looks like that one". Back then, we were young enough and crazy enough to just do it, so we measured Norm's garage diagonally from corner to corner, allowed just enough clearance to be able to sneak around the ends and started building.

Maiden voyage in maybe 1974 or 75. Cold and windy fall weather. Norm's in the bow and I'm in the stern.

 

[Mark Neuzil]

Todd, you looked like George Harrison. Norm looked like Norm.

 

[Max Peterson]

Back to the original question. I cut the thickness and width of strips to 7/32" X 5/8" before cove and bead for my 16' "Kruger" in order to allow the strips to more easily follow the sheer line without filler strips or steaming. It takes longer as there are more strips, but I noticed no difference in ease of sanding, weight, or strength compared with others. It was simply an aesthetic decision. The boat looks more like a banana, but I kind of like it. I'm not sure that I will do it again however.

Max

 

[Denis M. Kallery]

Max,
Actually it looks quite nice. Good Job!
Denis