Designs With Minimal Twist

[RoadRunner]

Based on my earlier posting about stripping a canoe with all walnut, Todd Bradshaw thought I might have a problem with brittle strips - especially with designs that require significant twisting. So, I need to find plans that don't have a lot of twist.

Can anyone make recommendations?

 

[Jim Dodd]

OK so no one else has responded.
Here's my take. Bigger canoes tend to strip with less torque required on the strips.
One I know that IS tough, is the Wee Lassie II, designed by Mac McCarthy.
I would favor thinner strips in any small boat.

Jim

 

[RoadRunner]

Thank you, Jim. Got some info from Ron up at Canadian Canoes today on this subject - Not sure how to proceed, but.....maybe a bigger boat design with less twist is the only way to go. Thanks again.

 

[Todd Bradshaw]

This is the sort of thing I'm talking about. Imagine a narrow wooden strip near the bottom that has to make the transition from sitting nearly horizontal toward the middle of the boat, to being twisted almost 90 degrees to vertical as it approaches the stem - and it has to make most of that transition in a fairly short distance, near the end of the hull. In many cases, these may be the older, "classic" designs, compared to many modern canoe shapes where the twist is spread over a much longer distance. Compare that canoe's shape to the rather bulbous ends of something like a typical aluminum canoe, with longer runs, no hollows and less twist needed if you decided to strip such a design. The classic canoes may indeed have a more sexy, graceful shape, but for stripping it can make the job more difficult in brittle wood. Since you're planning on working with an unusual wood not known for suppleness and long runs of straight grain it's difficult to predict how much trouble it may cause. One way to find out though.......

Strip twist is also going to be at least in part a product of which stripping pattern you use to cover the forms and piece the core together. Will you follow the sheer line's curve and work toward the joint at the keelline? Will you use the football method with a separate panel stripped up for the bottom and strips parallel to the waterline to fill in the sides? Either can make a good canoe, but the first one, though probably nicer looking, is likely to require a lot more strip twist.

 

[Dan Lindberg]

Hint for the ones that are twisted.

1) soak the strip a bit in warm water to loosen it up

2) run it long, 6-10 inches, clamp a small c-clamp to the strip and twist it by pulling on the c-clamp, once twisted, tie off the clamp and glue the strip to the stem, let dry at least 1 day.

Dan

 

[RoadRunner]

Todd, many thanks for the continued insights. Learning a lot with this question in particular. As with any project of merit, this will require much thought....

 

[Jim Dodd]

Though the usability of Walnut is a concern, I wouldn't let it overshadow picking the right design. I view this as my #1 priority !
No sense in building a boat, your not going to like, or use.

Jim

 

[RoadRunner]

Agreed. I think weight will also be a concern, but I'd rather have a stack of unused walnut and a boat I love.

 

[Todd Bradshaw]

Of course given the price of decent walnut these days you could always do what some folks do - sell most of the walnut to a furniture maker and use the money to buy cedar for the hull. A cubic foot of western red cedar is about 23 lbs. and one of walnut weighs about 15 lbs. more. A typical stripper hull in the 17' range probably contains maybe 1.5-2 cubic feet of wood in the core strips.

As for twist, hulls with minimal twist don't have to be bad performers. My all time favorite recreational and tripping canoes (the 17' x 34" and 18' x 36" Hazen Micmacs) when built using the football stripping method have very little twist involved in the stripping process, yet they are among the fastest, driest and most maneuverable canoe designs I've ever paddled.

 

[RoadRunner]

Again, excellent perspective. So, I'm gonna finally ask.... (newbie greehorn that I am) what is the football method?

 

[Todd Bradshaw]

You strip a panel over the bottom section of the hull using fore and aft strips. You then trim it to a football shape and at its edges it meets the first (the lowest when the hull is later turned upright) side strips. Side strips are fairly straight and level, though we found that putting a small amount (1"-2") of upward curve toward the canoe's 's ends is good. Otherwise, there is an optical illusion that happens, making the strips seem to look like they droop at the ends.

You can piece together an entire hull this way and the only place you need to bevel any strips is where the first strip meets the football. This kayak was the first stripper I ever built, around 1974 and both the hull and deck were built using the football method and then they were seamed together with inside and outside seams. You can see the straight football panel on the deck and the first side strip is the dark one running along the football's edge. Notice how little twist there is in the first side strip, and that one usually has more than any of the others.

On a canoe hull, it looks like this 18' Micmac (though obviously you can't see the bottom). Side strips are pretty level and any upward curve in the sheer line is pieced in with more level strips. It works great on designs that don't have a dramatic sheer line curve. For hulls with more classic upturned ends, the other method of stripping (starting at the gunwale and following the sheer curve, stripping down the hull toward a joint mid-bottom) usually works better, but may have more twist.

(sorry, really old photos)

 

[RoadRunner]

Really cool concept. I need to study this further....may actually be something I'd like to try out (walnut or not). Thank you so much.

 

[Dan Lindberg]

Todd,

I sure wish you wouldn't tell folks of this pattern of stripping.
On the top of your kayak it's not bad, but on the bottom of a canoe, there's not much uglier.
It 's even worse than staple holes and splices.

Dan

strip a panel over the bottom section of the hull using fore and aft strips.

 

[RoadRunner]

It may not be the preference of some, but I do find it interesting myself. Is this what we are talking about?

 

[Todd Bradshaw]

On the top of your kayak it's not bad, but on the bottom of a canoe, there's not much uglier.
It 's even worse than staple holes and splices.

Never bothered me, but beauty or ugliness is all in the mind of the beholder. As far as canoes and ugliness goes, there are a lot of things on canoes that I find far uglier than a stripper with a football-stripped bottom. I built enough strippers to pretty much get sick of the strip look altogether - in any pattern or with any amount of feature strip gingerbread. These days, I'd just as soon paint one, enjoy the sculptural shape of the hull and protect the epoxy from UV in the process. I'm even worse with kayaks. I don't care what they're made out of. The important thing is how they perform, and there are drastic differences from one to the next.

 

[Todd Bradshaw]

Is this what we are talking about?

Not really. In more typical football construction the football would probably end at the last crosswise mold and the rest of the canoe's end would be done with the side strips. Plus, that's a really bass-ackwards to do a football as the tapered and pointed ends of each bottom strip would need to be fitted individually, which is tremendously inefficient. In normal football construction the entire bottom panel is stripped at once, slightly oversized. Then it's trimmed to shape, followed by beveling the edge where needed to meet the first side strip, which is mostly as you approach the ends. Back when Norm and I were regularly building strippers the total time needed to bevel everything needed on a hull was probably 20 minutes and typical stripping time was one evening to do the football, then one side of the boat the following evening, and the second side the next evening. By the end of the evening after that, the hull would be sanded on the outside and was ready for glassing.

I'm far too impatient to glue on one or two strips per night, the way a lot of current builders do, or to spend a lot of time fidgeting with little pieced together inlay strips on what really is stretching the truth by even calling it a wooden canoe. Strippers can be really excellent boats, and as a one-off building method that doesn't require a lot of tools or a tremendous amount of skill they certainly have merit, but I tend to look at them more from a utilitarian perspective than as an art form. The main reason I ever started building them in the first place was because there were boat designss that I wanted to try and/or have that were not available. To each his own.

 

[Jim Dodd]

I find nothing wrong with splices, staples, and feature strips. But beauty is in the eye of the beholder !
I believe the football method, Todd write of is the same as Canoecraft method.
Here's a pic of one of those ugly staple ridden, splice laden strippers that use the Football method.

Jim

 

[Jim Dodd]

Oh one more.

Jim

 

[Dan Lindberg]

Jim,

Those are not the stripping pattern being talked about, the one in question is where all the center strips are layed straight and parallel to each other. After the glue dries, they are shaped to fit the center hole and glued in in 1 piece.

Dan

 

[Jim Dodd]

Dan
I've never done it that way, it seems like a lot of extra fitting.
My first was a herringbone bone pattern, and that seemed like a lot of work, compared to the way Ted Moores in Canoecraft does it. Fitting is only needed in for half of the football with Canoecraft.

Jim