ash ribs rebound

I just learned that we can apply shellac on canoes. Until now, I just used it for the handbar of my bike :D . I will search of it, but it appears that product is not during in time ? you have to re-apply every year ? Do you apply it after paint ?
I saw two types of shellac (I'm in France, so I have different a access to the products). A no-waxed shellac, and waxed shellac. Which is the good ? The shellac for my bike was in glitters, liquified in alcohol.
You want to use a waxed shellac. Dewaxed shellac will turn cloudy and white upon exposure to water. The merchants of dry, flaked shellac that must be mixed with, and dissolved in alcohol almost always indicated whether a package of flakes is waxy or de-waxed. Preemixed cans of shellac may or may not indicate whether they are waxy or not. But light or white canned shellacs have been de-waxed, and while fine for furniture, should not be used on a canoe. Orange (or amber) shellacs may be either. Though they are usually waxed, there is no way to tell unless the can's label tells you -- and they often don't. The brand that Jerry Stelmok uses (and which I therefore use), Zinsser Amber, gives no indication on the can, but it is apparently waxed.

A shellac bottom coat is applied directly over the filled canvas. Your filler is a bit unusual, by I don't think it will cause any problem if you do decide to shellac the bottom.

A shellac bottom finish is not usually chosen for aesthetics, but for function. Some folks don't much like the way it looks, and sometimes it can be pretty blotchy looking, especially after a time, or if not carefully applied. Though shellac can be applied with a brush, roller, or sprayer, it does not behave like paint when being applied. A couple of thin coats are better than one thicker; work fairly rapidly so you can keep a wet edge. I worked on one side of the bottom at a time, going from one end to the other; the overlap in the center when you do the second side is only slightly noticeable.

Changing the topic for a moment --

You may be interested in four videos made by my wife, Deborah Gardner, a historian who, incidently, has been on the WCHA Board of Directors for a few years now.

The first is
Contemporary Canoe Builders and Their Work
This video won the 2015 Best Documentary award from the Canadian Waterwalker Film Festival. Deborah did all the interviews and put the script for the video together from the interviews. Our friend Ed, a skilled videographer and editor, did the camera work and with Deborah's script and hands-on assistance, edited the raw footage into the final product. Ed had no knowledge of canoes or canoe-building; I helped in advance by taking him to the shops of a couple of builders (Jerry Stelmok, Steve Cayard) I knew, so he could get a sense of what we were undertaking. During the filming, I was basically a factotum, doing the odd jobs needed, and also handling the sound equipment.

We were hired for the second
Allagash River Canoe Trip with Mahoosuc Guide Service
Guides Polly Mahony and Kevin Slater wanted a video of one of their camping trips on the Allagash River to put on their website. We had been recommended to them, and after an introductory meeting, we were hired. Both Deborah and I shot the raw footage for the video while riding in the bows of separate canoes, Deborah with guide Polly Mahony and I usually with Jason Pardilla (assistant guide, a member of the Penobscot Nation, and descendant of Joe Polis, Henry David Thoreau's guide on the tipr the was the basis for Thoreau's Maine Woods). The video shows how a half-dozen strangers can have a good time together exploring a river none had been on before, with the relative luxury of knowing that a knowlegeable person has put the nuts and bolts of the trip together (transportation, food, equipment, etc.) and had the expert knowleldge to deal with anything untoward happening (none did). On this trip I learned enough about poling a canoe to run a workshop in poling at the next WCHA Assembly. I also wrote an article about the trip that was published in the WCHA Journal Wooden Canoe.


The third was prepared as an evening presentation for the WCHA's virtual Assembly in 2021, made necessary because the usual live Assembly was cancelled because of Covid
Professional Builders Shop Tour by Jerry Stelmok of Island Falls and Rollin Thurlow
Deborah played a major part in putting the virtual Assembly program together, helping several people who had little or no experience with making any presentation, not to mention a video presentation, create effective videos. Again, for this videao Deborah planned the two presentations and guided us -- the two builders and myself -- going through the two shops as I shot the entire thing with a hand-held camera while walking through the shops. I do not pretend to be a great photographer/videographer -- It's a bit rough and wonky, but not too bad for something done with little preparation and shot on the fly. Deborah can be briefly seen a couple of times in the background during the shooting.

The fourth is an in memoriam for Tom McKenzie
The Boat Connects the People; An Interview with Tom MacKenzie
Tom was important as one of the early builders active in the revival of interest in wooden canoes, one of three founders of the WCHA, a noted builder, especially of light-weight canoes, and an inovator of free style paddling. Deborah assembled this from some older unused interviews together with a good deal of new interview material. This video was presented at last summer's WCHA Assembly.
 
You can source some imported red cedar in France, and you can as well find some different species of cedar initially grown in France. There is still some cedar available in sawmills here and there, mainly from the great storm of december 1999.
Hello Étienne Henri,
Import wood from so far is a non-sense, I prefer use local wood. Anyway, I made this both of canoes from a trunk falls near my home.

Oh, and start with Rollin Thurlow's large scale plans and table to built the form : do not try to sort out full scale plans from a print in a book. That would be way too approximative
My second canoe is the Atkinson traveller from the Rollin's plans and table found in his book.

Joe,
Did you make your ribs out of green ash as you did for your stems ?
Yes of course. After saw it at the final dimensions, I let it dry for a month. Then I steamed it, normally the water heat leaches out the sap contained in the wood.
Then, after applied on the form, they dried for a month again..
 
A shellac bottom coat is applied directly over the filled canvas. Your filler is a bit unusual, by I don't think it will cause any problem if you do decide to shellac the bottom.
ok Greg, so, no paint after the filler. Just shellac. Well, I'm undecided.....
Could you tell me how many grams are needed for a complete hull?

Thanks for your videos, I'll take a look !
 
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Joe,
My son used one quart of shellac on the Traveller that we built. That's 946 grams. He had more than enough to apply multiple coats.
He used Zinsser brand pre-mixed shellac.
I refresh it every few years with a fresh coat or two.
Search on the word shellac on this site. It's often discussed.
 
This is a typical shellac bottom.
 

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Joe,
My son used one quart of shellac on the Traveller that we built. That's 946 grams. He had more than enough to apply multiple coats.
He used Zinsser brand pre-mixed shellac.
I refresh it every few years with a fresh coat or two.
Search on the word shellac on this site. It's often discussed.
Okay ! Thanks !
Maybe this will be ok ? :

This is a typical shellac bottom.
Cool! It looks great ! I think I will do the same
 
Joe,
I prepare my own shellac with glitters and alcool for artists. Can’t be easier. It is very useful for preparing wood, usually as a hardener, before finishing with wax or varnish.
You can buy some glitters from most cabinetmaking suppliers like Laverdure in Paris. I think I bought my last lot of glitters at Colorare in Tours, but they don’t offer them on their website. Pretty sure they have some in their shop though !
Have fun ! Étienne


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Joe, I am not a builder, restorer or repairer of wood canoes, so I won't comment on those topics. But I have paddled and raced all sorts of canoes and kayaks in all sorts of waters for 70 years, and I just want to comment on terminology, keels, rocker, and an important issue—transverse bottom shape—that Gil Cramer mentioned.

As to terminology, some diagrams help:

Diagram-side-view-terminology.jpg


The fore-aft (longitudinal) curve on the bottom of your canoe that you are concerned about is usually called the keel line (even if there is no actual keel). Whitewater canoeists often use the term rocker line, instead, because all whitewater canoes are heavily rockered.

The curve of the gunwales is called the sheer line.

The waterline is designed to be a particular shape, usually three or four inches up from the bottom of the canoe. However, in practice, the shape of the waterline constantly changes as you shift, add or subtract weight along the X, Y or Z axes of the canoe.

The curvature, if any, of the keel line determines the amount of rocker:

Diagram-rocker.jpg


Most recreational canoes designed for lakes and easy rivers have moderate rocker at each end. Looking at your photo with the superimposed blue ground, I'd say your canoe has a reasonable amount of rocker for a 17.5 foot canoe. If you have solid correction stroke skills—including correction at the catch (C stroke), the pull (pitch stroke), the exit (J stroke), and during a loaded slice in-water recovery (Canadian stroke), or the many combinations thereof—you should be able to paddle such a moderately rockered hull straight without difficulty. Particularly if you paddle from just behind center, so you can reach the on-side and off-side bow quadrants with static and dynamic draw, pry, jam and Duffek strokes.

As to a keel, I join those who advocate not adding one, at least not at first. If you are not a competent paddler, a keel will slightly help you go straight and slightly hurt you on unheeled turns. If you are a competent correction stroke paddler, who is also comfortable with aggressive heels to turn a canoe with stern slides, a keel won't matter. In either event, a keel will add weight, which you already have a lot of with a 17.5' rib/plank canoe. If you really want a protective keel to paddle in rocky 4" rivers, which I wouldn't do, a shoe keel would make more sense as a bottom-protective device.

Finally, I'd like to mention what might be your worst structural issue, the one that I believe caused Gil Cramer to burn a canoe. He said:

The ash ribs rounded the hull so that the canoe would just as soon be upside down as right side up. No matter what: that is a serious handicap.

A diagram of different side-to-side (transverse) bottom shapes, which some call deadrise (perhaps wrongly), helps illustrate the issue:

Diagram-bottom-shape.jpg


Many rib/plank wood canoes have flat bottoms, side-to-side. This gives them great initial stability but makes them slow to paddle. Very round bottoms are very fast, but have so little initial stability that they easily tip over; hence they are usually found only on racing canoes. Most designers of recreational canoes usually opt for what is commonly called a shallow arch (or sometimes an elliptical) transverse bottom shape.

The problem I'd worry about in your situation is not so much that the rebounding ash ribs are adding too much longitudinal rocker, but that they are bulging into too much of an unstable transverse round bottom. I'm not sure how you can definitively test this issue short of floating your hull. Nor, as I've said, do I have the expertise to advise how to reduce such an unstable round bottom bulge, if there is one.

Best of luck!
 
Thanks a lot Glenn for your precious tips ! This will help me so much !
After checked the bottom of my canoe, the transverse curve is not too pronounced. It's somewhere between the flat and round. I will see the stability at the final stage !

The canvas is applied !
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Looking good.
It appears to me that the Atkinson Traveller lines are much more natural than François Sergent's design of your previous canoe. Isn't it the one hereafter ? It is very much the archetypical French canoe of the period : flat bottom, rocker, etc. are more dramatic than the refined all wood canoes produced near Paris in the 1920's.
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Transitions are very quick and I believe it may be difficult to ply wood following this design.
Now I never built a canoe so I may be wrong ! Just a question, please : why not cutting the ribs ends before applying canvas ?
Etienne
 
Yep it's it. But I started this one because it's the first plan with complete instructions I found. And at this time I had no knowledge or experience about canoe construction.. just some little skills about wood working.
With a Japanese saw, I prefer cut after the outwales will be installed. The result will be neater, and the ribs will align perfectly with both inwale and outwale.
 
I see, thank you.
Regarding F. Sergent's design, the sheer line is pronounced, and the rocker is, say, noticeable. Those characteristics may belong to Sergent's first training : designing high seas sailing boats. It is another story to design rowing skiffs or canoes. This canoe really is a strange design : I mean sheer line and keel line don't "line up" with the flat bottom (and it is very flat !). We should remember Sergent produced a few designs like this canoe while he was jobless at the beginning of WWII : he had no way to control his designs, no materials to build them, and probably very few communications with fellow architects.
Looking at your first picture, given your ribs didn't keep Sergent's rapidly transitioning lines, you may have ended pretty close to his plans !
 
Later during WWII, Sergent designed two more canoes which I always found more convincing : see hereafter. The "canoe de croisière" is thought to be a sailing canoe.
Now, considering late canoe design in France, from the 1950's or 60's, I always prefered those produced by Chauvière or Rocca

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Let's say the first one is a learning prototype. Maybe if I had seen Rollin's plans before, I would have opted for those. According to Sergent, many canoes were built based on his plans. But I don't know if they were able to perfectly maintain the design, especially since in his instructions, he recommends holding the ribs to the mold with a simple nail ! A nail that should not be completely driven in, serving as a garboard. Just with this technique, it is impossible to maintain the flat shape of the canoe, but I didn't know that...
Notice the ribs nailed on my first construction:
The ribs extend up the sides of the nail, at the center.
PXL_20210930_162043129.jpg
 
Evening Joe,
Your picture says it all … this is why I was raising concerns about François Sergent’s designs and books. I mean you do not build a canoe upon a keel like it is common practice for a sailing boat in Europe.
Keep us updated about your Atkinson Traveller built : did you build a stronger form ?
Etienne
 
Hello Étienne,
Nope, It's a wasted time and materials to build a solid form just for one canoe. I used this first light method, and I improved it following the tips of Alex comb's one-off canoe form (it's a new article, I didn't found my first link) :

I started to put the filler (tonkinois +silica, and birch tar for the stems). Like the first built, the canvas applying and filling is a very stressful time ...

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