Placid Paddler

I've heard that too Rex. To explain it a little more as best as I can, it allows for slightly more hollow at the bow when viewed from a cross section. The bottom split is skinnier so it allows the boat to slice through the water in smooth conditions. The upper part of the split creates a wider section of the skin. The wider more buoyant section allows the front end to bob over waves. So the idea is to have a front end with good flat water speed that doesn't sacrifice seaworthiness. This couldn't be easily achieved without the split as the skin would naturally stretch taught and even out the width differential. Now for the disclaimer: this is purely speculation from smarter people than me who have observed the boats. We can't talk to the developers of the original concept and ask them why for obvious reasons.

Found another documentary of a traditional skin on frame kayak and another bark canoe. These kayak builders have some strong teeth. You'll see what I mean when they bend frames. http://www.nfb.ca/film/building_kayak_pt_1 http://www.nfb.ca/film/building_kayak_pt_2 http://www.nfb.ca/film/cesars_bark_canoe

I drew up a sketch to illustrate the concept.

You are the expert Kudzu. That is good real world data right there. I guess like all things on the internet, skin boat toughness tends to get overrated. Looks like I will be going back to building Kevlar and fiberglass for any boat that sees shallow water use. EDIT: I'm just spitballing here, but how about stapling a layer of Kevlar stretched across the bottom stringers, saturate it with epoxy and add a layer of fiberglass over that for abrasion resistance. The rest of the covering would still be polyester fabric. That would keep the exotic fabric and epoxy costs down and still make for a very lightweight boat that has good abrasion resistance in shallow water.

I'm stuck renting a room in a house for the winter, and the only place I can work on boats is two hours away. I'm moving into a new house at the end of January with a nice detached garage for a workshop, but until then I'm just planning for next season's boats and killing time watching documentaries. I wanted to post a couple if anyone is interested. I'm a single blader so I mostly watch canoe themes. I'd like to build a SOF kayak down the line, but right now it would just be a frame to hang on the wall for decoration. Does anyone know of any good kayaking documentaries, especially traditional crafts history and construction? I know most of you are kayakers, so maybe you can help convince me there's more to kayaks than cramped legs and dripping water. Bill Mason documentary from the 70's. He's a great canoest and nature lover. Waterwalker chronicles his journeys through remote rivers and lakes in Canada, as well as some of his art and philosophy. http://www.nfb.ca/film/waterwalker More Bill Mason. These are mostly instructional if anyone here wants to learn how to control a canoe (and share a canoe without the fear of divorce). http://www.nfb.ca/explore-all-directors/bill-mason/ A great film documenting the construction of a birch bark canoe. Same guy as the previous video, taking the canoe on a wilderness trip.

Constant abrasion will wear through the skin. I don't mean to be abrasive and I'm not trying to say PL will make an indestructable whitewater boat, only that it could provide more abrasion resistance than paint or varnish alone. If I understand Marvin's posts correctly he wont be taking this in serious whitewater. He said current and some mild rapids. Cedar canvas canoes were used successfully in rivers for a hundred years. Marvin should probably just buy a plastic river kayak, but if he wants to build his own boat maybe one of the more open top recreational designs like the Mess About or the FreeB would be better for a river. A wider bottom with more surface area would reduce the single point contact versus the knife edge keel open water boats. A lightwieght SOF boat would be easier to carry over low water obstacles and gravel, and an open top would make you more likely to jump out of the boat to do it. Excellent point about getting trapped in the boat. Another good reason for a large opening on top

On the topic of abrasion resistance, Dave Gentry has used PL Premium construction adhesive as the skin coating on the high wear areas of his boats. It bonds to polyester and nylon, but it is not UV resistant so it still requires a layer of paint or varnish for protection. I've used it in other wood working projects and is really durable and hard to sand, so it could be good for shallow rivers. The tubes only cost $5 at any hardware store. You just squeeze it out and spread it into the weave. http://forum.woodenboat.com/showthread.php?121817-New-SOF-skin-coating http://www.kayakforum.com/cgi-bin/Building/index.cgi/page/1/md/read/id/208339/sbj/skin-on-frame-durability-of-pl-premium-coating/

DJ, you should be able to get baltic birch pylwood from any Menards in Michigan. You may have to have it shipped to your closest store, but they will get it for you. Also, check around at other lumber suppliers near you. Spend a couple hours making calls and I would bet you can find baltic birch plywood, not birch, "baltic birch" is key. If I can find good plywood in Kansas, and you can't in Michigan, you haven't looked hard enough.

Or just build a couple canoes, and you can make your kids haul all of the gear.

Jeff, the green guideboat is from one of your customers. I came across it over at the wooden boat forum. I talked to Brian at Cape Falcon Kayaks who has built a few SOF guideboats. Here is what he had to say about the hollows: "The lines are usually only hollow in one plane. Fore to aft the lines are straight, meaning that they conform a lot better than you'd think, a few spots just barely don't touch. Water pressure takes care of that though." so I think it can be pulled off without too much deviation from the historic lines.

Thanks for the replies Jeff. It will be a challenging design, especially for my first SOF. I really should start with one of your designs, but I already have a canoe in the works and I have never liked kayaks (blasphemy around here, I know). The issue with skinning the hollow cheeks was going to be another question of mine, but I was planning on asking somewhere else where they have made SOF guideboats before. I like your method of framing so thats why I asked that here. Here are some links to other SOF guideboats where they managed to skin the hollows. http://s1229.photobucket.com/user/guideboat/media/26Done.jpg.html?sort=3&o=3 http://www.capefalconkayak.com/adirondackguideboat.html Also, thanks for answering questions about a design you aren't affiliated with. Maybe after the kinks are all worked out, and I have a more complete set of plans we can put them in the next book "How Many More Fuselage Frame Boats Do You Need?". Your second book should be arriving at my house soon, so I will have much more reading to do, and I might just end up making your rowboat first to get the hang of things. I can always tell my girlfriend that I made it for her. Whatever I find out about the hollows I will forward here in case anyone is interested.

Hello all. New to the forum. A little background, I'm finishing up a kevlar and glass canoe, but it is too cold for epoxy work, so I'm just waiting until spring. The kevlar canoe has been a fun build, but it has taken longer than I thought and I'm also realizing that epoxy work is a PITA. I bought Jeff's first book last spring and read through it, but originally didn't think it was my thing. Well after mold making and epoxy I've changed my mind and my guideboat will be SOF. My question is about frame spacing and plywood thickness. I originally transfered the measurements from the book "Building An Adirondack Guideboat" into a CAD file planning to make another Kevlar boat, so I have 16 stations spaced ~10" apart. The boat is 16 feet long. Using the method outlined in Jeff's book I assume I could throw out half of those stations and make 8 frames spaced ~20" apart made of 3/4" baltic birch. So the question is should I do 8 3/4" frames or stick with the original plan and use 16 3/8" frames? Which method do you all think would be most structurally sound? Should I go even thinner (I have access to any thickness of BB)? etc. Extra cutting and lashing time would not be an issue for me. As a side note for Woodman, I am also in the KC area and I called Metro Hardwoods in Independence and they have a wide selection of baltic birch plywood in 5x5s and 4x8s. I don't know if they will be cheaper than Liberty Hardwoods though. I'll post a picture of my plans here, and if anyone is interested I can send you digital copies that can be printed on a plotter. Thanks.