andy00

Those boats are stitch-and-glue or wood strip. Nothin' wrong with that, but they ain't skin-on-frame. Yostwerks is all SOF.

No direct evidence, but the general rules are that smaller beam is better and multi-chine is better. Therefore, Long Shot and Firefly look like the best bets. If you want a boat with even less beam, you need to check out yostwerks.org.

Hello Europe! It's been many decades since I studied strength of materials, but I don't think your calculations capture the whole picture. You're ignoring the modulus of elasticity, which has to do with how the wood bends. Based on ratio of the average densities of the two types of wood (26:23), you could probably save only about 2 pounds. We must also keep in mind that there is significant variability among trees of the same species, among sticks from the same tree, and among how the sticks are sawn. We're not dealing with a more uniform material like steel. Look at the grain of each stick (how much runout is there? How tight is the grain?). Flex each stick. And then decide the scantlings that give you a good feeling. With nice, straight-grained fir, you could probably go 1/16" smaller, but I'm not sure that it's worth it. Have fun!

Love those native-style paddles! Who wants to use a factory-made paddle with a hand-made boat? They work well, and if it doesn't feel quite right, whittle it some more or make one a bit different. Wood paddles are also good winter projects. The one I've settled on for use with my Ravenswood is the 4th from the top, which is a hybrid West Greenland/Aleut model (8'-7").

Daedalus: Nice boat! The rocker isn't necessarily off; saying that it turns slow but tracks great is like saying "It's hot out but not cold." On the kind of big water in your video, you'll find great tracking much more important. For quicker turning, learn to edge your boat and use sweep strokes. There are lots of videos on line showing the techniques. Also, as a former safety manager, I can't sign off without reminding you to always where a PFD. Have fun, Andy

Jeff: Wishing you a speedy recovery and fair winds! Andy

Another option for stowing gear in a SOF kayak is use of combination dry storage/flotation bags. Flotation bags are really important for safety in any case. Check the following websites: nrs.com salamanderpaddlegear.com skin boats.com

I don't know the particulars, but composites are typically less stiff than wood. They don't have the long fibers of wood. You might have to increase the scantlings. On a boat as small as the tadpole, it might be OK. But you can use other woods in place of WRC, e.g., other cedars, pine, or spruce.

So, what's the result of the failure analysis? Was there a knot or odd grain where the stringer failed? Any other evidence that could help prevent such an incident in future projects?

Dear Mr. Chair: If causing an unfair curve is a concern, you can carve a little curve into the butt block. But I think that you will find that less curve is needed than you might think. As far as clamping, consider lashing, cable ties, and/or screws. If you use epoxy glue, you don't need a tightly clamped joint, as the glue will fill the gaps. Remember to put some plastic sheet (e.g. plastic bag) between the stringer and the skin to avoid gluing them together. Have fun!

Looks like it could be repaired with a butt block. The two butt blocks shown were used in the original construction in lieu of scarf joints. They are the same scantlings as the stringers they are joining.

Intuitively, it seems to me that (in the case of a fuselage-frame boat with single chines) the five full-length longitudinal members (keel, two chines, and two gunwales), which are tied together with the stems, the frames, and the skin, provide almost all of the overall structural strength. Deck ridges are mostly for more localized purposes, such as providing a place to rest your fanny or room for your knees. Have you checked out www.yostwerks.com? There are a number of designs there with various combinations of single deck ridges, double deck ridges, and no deck ridges. Have fun

Traditionally-built Greenland boats typically have two longitudinal members (deck ridges) that run forward from the masik over several of the deck beams, which run athwartship. Some fuselage-frame boats have similar bits. But the two construction techniques are quite different and comparisons can be tricky. There are a variety of arrangements among fuselage-frame kayaks including single and double deck ridges before and after the cockpit. Before the cockpit, they make room for knees. After the cockpit, they serve as (as Jeff calls them) fanny beams, to rest your fanny as you slide into or out of the boat. As far as structural implications, it's hard to say, but it's usually a good idea to build as the designer intends. Fair winds

Both your boat and your English are dandy. Thanks!

Curious phenomenon. I was trying to imagine if that could have occurred on my Ravenswood and it seemed unlikely. So I looked at the plans for Poco Barca in "Fuselage Frame Boats" and see that distance between the #2 frame and the #3 frame (the area of the unfair curve) is 26 inches. On the Ravenswood, those two frames are only 18 inches apart. That difference certainly could contribute to the reverse curve. Of course, the species of wood used for the stringers, the characteristics of the particular pieces, and their scantlings could also be factors. As to performance, the curve of the gunwale probably doesn't mean much, but the curve of the chine could affect the hydrodynamics, but not necessarily in a negative way. We'd need some towing tank tests to sort it out. Fair winds

Dear Bay Stater: Consensus is that Baltic birch plywood is the best material for frames, although other types of plywood will work. BB is strong, stable, and it cuts clean, compared to other plywoods. I hope that other forum members will weight in on this. Have fun!

Very nice! Cool two-tone paint job. Please tell us how you did the nice lettering.

Fernando: Please post photos so we can watch your progress. I may start on a new boat after I catch up with some spousal assignments. Fair winds

Welsh4life: Very cool boat! So you need to share with us 1) How you did the faux stitching and shading, 2) how you constructed the coaming and thigh braces, and 3) do the thigh braces work well? They look to be a bit high. By contrast, I tuck my knees under and to the outside of the coaming. In the photo below, you can see the dirty knee print.

Traveler: Jeff and Abyssdncr got it right. Also, think about the benefit of a lighter boat, which is real. Light boats get used more because there is less work involved. However, once a boat is light enough to get on and off your roof rack and into and out of the water easily (which varies, depending on your strength and agility), any further reduction in weight is insignificant. Have fun!

Balvar: You were right the first time. Fly Fisher is in Jeff's book "More Fuselage Frame Boats." It is a 13.5 foot pulling boat. I, too, have wondered if anyone has built one. There are other examples of SOF pulling boats out there.

Balvar: If you want a kayak, definitely consider one of Jeff's skin-on-frame designs, but, like Dave says, think about plywood if you want a Jon boat. Try the link below for a whole bunch of easy-to-build plywood designs by Jim Michalak. For a jon boat, check out "Pole Punt" under the "Paddleboats" category. But while your at it, look through all the designs. You might find something else that meets your needs or scratches an itch that you didn't know you had. Have fun, Andy https://www.duckworks.com/jim-michalak-s/122.htm

If you want to learn all about it, see "USDA, Forest Service Handbook No. 125, Bending Solid Wood to Form, 1957." See link below: https://www.fpl.fs.fed.us/documnts/usda/ah125.pdf

Uncle Frosty: Nice! So give us a review; how does she paddle compared to other boats you've paddled? Regarding the position of a bow seat, serious canoes sometimes have a bow seat that adjusts fore-and-aft to trim the boat to account for the weights of the stern paddler, the bow paddler, and any gear. They are sometimes known as "slider seats." See example below. Paddle on!

All of these are outboard boats, but you may want to check them out anyway. From Jim Michalak: 1) Brucesboat and 2) Dorado. From the great Phil Bolger: 1) Slicer, 2) Fisherman's Launch, and 3) Sharpshooter. Have fun.