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  1. Thanks @lattenkracher and @andy00! The paddle I also made by myself after this and this instructions. andy, I have to admit that I only bought one now, but it will be part of the basic gear in the future!
  2. On Saturday I finally launched my Curlew, after a build time of a little more than year. Here are some pictures!
  3. That is indeed a much smarter way to install the coaming in a watertight fashion. Filing groves to accommodate the rolled fabric on the front and back seems so obvious now! I'll link to your post from the coaming part. You have a beautiful boat! Did you add these two extra frames in the cockpit to have shorter floorboards, or is this already like that on the original plan? On the curlew the floorboards are quite a bit longer than necessary.
  4. Link to this post EDIT: I have now also added a build log, scroll down it is below the materials. Hello, I have now almost finished my Curlew Kayak from Jeff Horton's book Fuselage Frame Boats. I had some time to go through the notes I build, and I realized that a large part of time was used by finding suitable materials. I am located in Austria (Europe!). Wood I bought from local timber dealers. Most other items I bought from web stores in Germany, but they ship to most places in Europe for a slightly higher shipping fee. Therefore there might be some German words in the post below, apologizes for that but it makes it easier to identify it or search for similar items. So here is an overview of which materials I have used including links and price. I also added some notes on what I learned about it, how I choose it or some general hints. Another sometimes challenging part was the conversion from the imperial measured used in the book to the metric system. Hope it is of use to some future builds and saves somebody the time to do it. As these links to the articles will probably stop working (actually some already did, because stores change their articles), I tried to include as much information and key words as possible. That should help find something similar. Plywood for Frames: I have used this here . It is 12mm(being the closest to Jeff's suggested 1/2" thickness) birch plywood of good quality. I used it for the the frames and the coaming, but since the smallest amount sold was 3m x 1.5m for 56€, I still have enough for another boat. Article name was: Sperrplatte Birke BB/BB 9-fach EN314-2/KL3 If you are looking for plywood, make sure it is of class 3 (KL3, former AW100) which is rated for unprotected outdoor use, according to this website. BB/BB refers to the quality, or how many and how large knots or branches are allowed. I am not sure if this only refers to the outermost layers, as sometimes it looked like there branches on the inner layers. Considering that, I think one could get away with somewhat lower quality, as it is quite unlikely that all 9 layers have a branch in the same location. It is quite heavy with a density of 700kg/m3 (or 8.4kg/m2). I saw others have used Okoume Plywood (also sometimes named marine ply), which is lighter and has a better rot resistance, but I couldn't find any close to me. Here is are timber dealer that seem to sell it, ask for Bootsbausperrholz in German. Sometimes it has inner layer of poplar (deutsch: Pappel), and I not sure of this is suitable. Holz-HRAD Ges.m.b.H.; Haböckgasse 5; Austria-1230 Wien Holzfachmarkt HOLZWURM 2700 Wiener Neustadt - Zehnergürtel 110 Kurt Wolf & CO KG ::  1050 Wien ::  Margaretenstraße 124 Here are some more thoughts about plywood selection. I also used this plywood to make the floorboards. To save some weight, I drilled some large diameter holes into it. Here is a picture of one of the frames to give you an idea how the plywood looks like: Strongback and Brackets: I had a timber beam from a recent construction left over which I used, so the cost was 0€. I put it on top of saw horses that I had at home. Also the brackets for the keel I made from some scrap pieces that were lying around. Set up, it looked like this: Timber for Gunwales/Stringers: In most American builds Western Red Cedar is used, as it is light, rot resistant, and has little knots. I could not find it in my area. First I considered to use fir, but it was not available in the quality I needed in the local timber dealer. Forget hardware stores like OBI or Bauhaus for this, all the pre cut wood laths are too short and expensive for what it is. It took me a while to figure out the proper terms in the timber dealer world, but once you know it is easy. For the German speakers: ask for Wertholz Tischlerware. In my case it meant planks sawn from the lowest and widest part of the tree, which is straight and has little knots. On the receipt it said: 57427/0133 FICHTE TISCHLERWARE "UNBESÄUMT" KD PLUS 700€/m3 KD stands for chamber dried, not sure if that is a good or a bad thing for the intended use. I had no problems bending it though. After explaining that I plan to rip cut it into thin strips and sorting through a stack of these plates, the friendly man gave me one that had a few light cracks from improper drying (doesn't matter if you scarf some things anyway) for a small price. It looked like this, unfortunately I did not take any better pictures: The plank was a little more than 4m long, 4cm thick, roughly 30cm and 40cm wide on the ends, and still had the bark on the sides. This was enough for all stringers and gunwales, and I still had enough to replace one of my gunwales because it had a strange tension and cause a corkscrew twist in the frame after taking it from the strongback. This can be avoided by matching opposing stringers and gunwales such that they need an equal force to be bent into shape. . Here is an explanation about it. Having similar grain orientation in the cross sections helps. Using a quarter sawn plank (deutsch: wagenschott) to cut the stringers from would probably be smart next time. It cost only 22€, that I then ripped on a tablesaw with the help of another person into 15mmX25mm keel/stringers and 15mmX38mm gunwales. Lately I realized there are some dealers specialized in special woods around. However they are quite far away and it is much more expensive. Here is one in Austria: Mühlbauer Holz GmbH Franz-Lehn-Gasse 7, 2325 Himberg Here is one in Germany: Holz-Henkel GmbH & Co.KG Hannoversche Straße 41; 37075 Göttingen Also an interesting option is Paulownia wood, which is started to be grown in plantations in Spain and Italy. It is very light (0.26kg/m3, compared to my spruce with 0.46kg/m3), rot resistant (unlike my spruce), grows straight with little knots. The two stores above seem to have it as well. It is also sold online, but I asked out of interested and the shipping was quoted with 85€. ipaulownia.com and paulownia-baumschule.de are examples. Glue for Scarfs: I had Ponal Wasserfest Holzleim at home, and that's what I used. However I read that it is only rated for moist environments like bathrooms ( or outside), but not for submergence. Probably not going to be a problem as long as I make sure the boat dries properly after use (which has to be done anyway). But next time I would use a polyurethan based wood glue, which is truly water resitant. Gorilla Glue is an example for this. Wood Finish for the Frame: Some people report problems with boiled linseed oil, so I decided to use Tung Oil. It seemed to be quite similiar to the former, so I think "Leinölfirnis" would be fine as well. The Tung Oil was 18.9€, shipping was free. Don't use any finish that seals the wood. Any small defect is a entry point for water, but it can't dry off anymore! On the other hand, yostwerks seems to cover the frame on epoxy. Some discussion is here. Lashing Material, Artificial Sinew: I used this one on the recommendation of the user lattenkracher. Article name was: Wachsgarn Kunstsehne braun teilbar, 22,57€ incl shipping, for 120m Curlew has 63 lashings, so it roughly needs 63*1.2m= 75m. I ended up needing to spools because I put a few more turns than recommended in the book to be sure, and also when troubleshooting corkscrew twisted frame I opened and redid quite a few lashings. Without that, one spool would have been more than plenty. Shops Impressum: Ledermacher.de; Molkereistr. 8; 86681 Fünfstetten; Deutschland If you don't lashings, you can also glue the frame together with epoxy. Keep on mind however, that lashings can be undone easily. For me it was a major advantage, as I had to replace a gunwales because it caused the boat to corkscrew twist. Fabric for Skinning: This part was very hard and took a lot of time to figure out. Jeff is suggesting to use uncoated polyester with a grammage/weight/strength/thickness of 8oz/yd^2 (=271g/m2). Convert to metric using 1oz/yd2 = 33.9 g/m2 or use this online converter here. I ruled out nylon because I don't want to have a saggy skin on my boat when, which tend to happen to nylon as it gets wet. Uncoated polyester proved to be impossible to find in fabric stores. Apparently it is used in industrial filter facilities, but it is only sold on roles with 100m, which is maybe a bit much if you build just one boat. The next best thing I found is polyester which is coated on one side (german: beschichtet) with PU (polyurethan). One side feels smoother than the other, that is the one that is coated. You might know it from backbags, where the the fabric on the inside feels a bit smoother than the outside. The important thing for skinning is that the fabric can be pulled and twisted without wrinkles getting created. E.g. take a tshirt and pull the fabric to a square between your hands with thumbs facing up. You can twist/rotate it (rotate one thumbnail towards your toes) and you can pull it diagonally (moving one hand further away from yourself, toward your front) and if you pull apart hard enough no wrinkles are formed. Now try the same with a sheet of paper, and you should notices the differences. The paper will start to warp. This disqualifies, at least in my opinion, PVC coated fabrics (they will behave like the paper), as it will not neatly fit around the frame and it will look a bit baggy. It can be done however, Tom Yost from yostwerks is doing it that way. Actually plain PVC is used there, but it probably behaves in a same manner. The advantage is that you don't need to paint it though. Dozens of this fabric can be found at extremtextil.de . Back to the polyurethane coated fabric. Compared to uncoated fabric is has one more advantage: it can be cut with scissors instead of a hot knife, as the fibers of the fabric are held together by the coating. Here is an example of this fabric in use. Article Name: Polyester Oxford 600D Wasserdicht Outdoor Stoff Segeltuch Abdeckplane With 600g/lfm=375g/m2=11 oz/yd2 it is on the thick side. It seemed a bit thick to me, so I ended up using this one, Article Name: Polyester Oxford 250D - Wasserabweisend, Winddicht, Outdoor Stoff, Gartenmöbel Stoff (Saphir) With 250g/lfm=156g/m2=4.6 oz/yd2 it is on the rather thin side, but I plan to use it on a flat, deep, open lake. Keep in mind that some stores give the grammage (german: Grammatur) not per square meter, but per running meter (german: lfm für Laufmeter), so in that case it has to be divided by the width to get the g/m2 number (e.g. 300g/lfm at a fabric width of 1.6m would only be 300/1.6=~187g/m2). This has happened to me, so now my fabric is a bit too thin at 250g/lfm=156g/m2=4.6 oz/yd2 I ended up paying 7,49€/lfm, for 6m including shipping I paid 54,84€. Unfortunately it did not shrink at all when applying heat with an iron, but luckily I realized it before sewing. So I made sure to sew it on drumtight already. Another option could be nylon, which can be found here: Article Name: ballistic nylon hochfest rohware 850den 310g qm capfalconkayaks seems to be using something similiar, if you look at this video Keep in mind that nylon and polyester behave differently and require different sewing techniques. Stores that I have found to be useful: extremtextil.de pure-textilien.de stoff123.de String for Sewing: I used this: Handelsminister.com Jalousieschnur Plisseeschnur 100m Zugschnur für Plissee Raffrollo Jalousie Ersatzschnur, Farbe:weiß, Durchmesser:0.8mm It is synthetic so it won't rot, not too thick so it can be still sewed easily, but hold quite a lot of force when I tried to rip it. 15.17€ incl. shipping Thicker or thinner diameters are also available, but it probably does not matter too much. Paint: I have bought this one: Sikkens Rubbol Satura from farbekönig.de This was recommended to me by a boat builder in a facebook group, how has used it on his skin on frame kayak. He also mentioned that using transparent paint does not protect the fabric from UV light as good as coloured paint, and therefore might need a reskinning earlier. I estimated the area of the curlew by modeling it as a cylinder: A=0.3m*pi*4.5m=4.2m2 Using the calculator on the website I will need a bit more than one liter. Since there are only 0.5l, 1l, and 2.5l sizes available, I decided to buy 0.5l white as a first layer, and then 1l with the color of my choice. RAL color palette is avaible, from which I choose "RAL 1016 Schwefelgelb" (engl. sulfur yellow) with the reasoning that I would like to be seen even in bad weather conditions. 78,98€ incl shipping Another, probably even more durable option would be a 2 component polyurethan. Here is a discussion about it in German, with some people recommending Coelan. However it seemed quite expensive, and since all this boat project is already complicated enough for me, I thought learning how to use a 2 component paint on a rather large surface was another rather large task. Corey's Goop is also mentioned in this discussions. A third option, at least for nylon, is epoxy resin coating. Capefalconkayaks is using that method. An attentive reader has pointed out to me, that capefalconkayaks actually uses a 2 component polyurethan coating. I tested the white color on a small leftover piece. I realized when using more than 10% thinner, it soaks so much into the fabric that the inside is getting ugly white stains, therefore I will stay with 10%. I also realized that if the "backside" is painted, none of the soaking appears. Therefore this must be the coated side. I have skinned my boat the smooth (coated) side of the fabric on the inside, but in hindsight it might be better to have that side on the outside as it is smoother already. I have not painted my boat yet, as I am waiting until the garage is warm enough. I will update when it is done. Some more discussion on Skin Paint. If you want two colors and wonder which combination will look nice, this color wheel might help. Deck Rigging: Leather strap that I cut into strips for the rigging: Team Beust 120-150 cm x 6 cm Latigo Lederriemen 4-4,5 mm Riemen Gürtelriemen braun - 150 cm; amazon Look for: vegetable tanned leather, latigo leather 30€ incl. shipping Backrest: I use a simple one: Kanu Kajak Boot Stuhl Rückenlehne; aliexpress.com 11,35€ incl. shipping There are many options available, also complete seats. Float Bags: I made float bags from this material: Nylon 210 den einseitig TPU beschichtet 275g qm schweissbar; extremtextil.de Here is some information (in German) about the welding itself, but it also translates well with google translator. For the curlew kayak float bags, I needed 2.5lfm and paid 58.56€. Which I am happy to pay as I want these floatbags to be reliable! Which can be welded at home using an iron for clothes. I took the directions from Cunningham's book. As a airtube for inflation I used this: Glasklarschlauch PVC 12mm; OBI 8,37€ To glue the tube to the bag, i am using this glue: UHU weich spezialkleber transparent, OBI 5,99€ NOTE i am still experimenting with this glue, but so far it looks promising. Here is a picture of the cut out but not yet welded float bags: Footrests: I bought these adjustable footrests from amazon for 26,76€ including shipping: footrests, amazon There are many options available, search for: kayak kanu footrest Some people make their own adjustable footrests from plywood, see here. Here is how it looked assembled into my frame. I had to cut a small piece on the left side, to make it fit: Keel Rub Strip: I plan to use cut this one in middle, using one half for the bow and the other half for the stern: Flachstange Messing 2 mm x 10 mm x 1000 mm; OBI 7,99€ Not sure if I will screw or glue it on though. Bilge Pump: 46cm Kajak Hand Pumpe; aliexpress 13,27€ incl shipping Expenses: Below the expenses for the materials above are listed. Not included are some books that I have bought, some tools that I did not have in my workshop before, and two cans of paint that I used for experimenting. 56€ Plywood 22€ Spruce Timber 18,9€ 1l Tungoil 22,57€ 120m Sinew 54,84€ 6m of Polyester Fabric 15,17€ Sewing String 78,98€ Paint 30€ Leather for Deck Rigging 11,35€ Backrest 58,56€ Floatbags: TPU Nylon Fabric 8,37€ Floatbags: pvc tube 5,9€ Floatbags: glue 26,76€ Footrests 7,99€ Keel Protection 13,27€ Bilge Pump ------------------------------------- 430,66€ SUM Could it be done cheaper? Sure, maybe it can be halved by using cheaper materials e.g. boiled linseed oil insted of tung oil, a cheaper string, a cheaper paint, instead of leather for the rigging use some cheap polyester roper. Omitting the float bags, keel protection, and bilge pump also saves money. Footrests can be made DIY style as linked above. However since I consider this as a hobby project, I don't mind spending some more money here and there to have a nicer boat, which is fully equiped and a bit safer to use . It was also a lot of work for me, so I hope the better paint will make it last a few years more before reskinning is necessary. How many hours did it take? Jeff says in his book, that he needs about 100 hours to finish a boat. I am a first time builder, and so far I am at 160 hours. I still need to paint it and add the deck rigging, but in the end it will be (sparing unforeseen problems) around 170 hours, which seems alright. This is only includes actual working time in the workshop. What I have not logged are the countless hours I spent researching and learning how to do certain tasks that are necessary, sourcing materials online, and thinking about ways how to fix the corkscrew twist problem I encountered. I would only recommend starting to build a boat like this if you have the space available, and the boat can be left there for extended periods of time. Also you shouldn't be in a rush to finish it. Life, as I have came to learn, has a habit of getting in between you and your boat project! Paddle A kayak needs a suitable paddle. From a spruce plank that I bought for 10€ (from the hardware store OBI. I had to sort through all the planks there to find a suitable one with little knots and branches), I made a simple Greenland Paddle using this free instructions here. It only has 800g and took about one day in total to make. Here is a picture of the paddle after treating it with boiled linseed oil. Here are some more links (in no particular order) on how to make a paddle, and how size it for your body: https://www.youtube.com/watch?v=Jk8lsC-rBSU https://kajakkspesialisten.no/e_annet_lageare.php https://gramkajak.com/choose-your-paddle/ https://www.kayarchy.com/html/01equipment/021greenlandpaddles.htm https://tuktupaddles.com/measure_paddle.html https://www.joeopaddles.com/greenland-paddle-sizing Used Books: The main resource for instructions I used was of course this book, which also included the offsets: Fuselage Frame Boats: A guide to building skin kayaks and canoes; by Jeff Horton There is more info available on his website, and some videos on youtube that explain e.g. sewing. Here is an overview of the books I also looked into: More Fuselage Frame by Jeff Horton Building The Greenland Kayak, by Christopher Cunningham Building Skin-On-Frame Boats, by Robert Morris Building a Greenland Kayak, by Mark Starr Kayaks of Greenland: The History and Development of the Greenlandic Hunting Kayak, 1600-2000 by Harvey GOLDEN Canoe Paddles: A Complete Guide to Making Your Own, by Graham Warren Building Strip-Planked Boats, by Nick Schade Used Forums: I linked to some relevant posts on these forums already: messing-about.com forum.woodenboat.com, where Jeff has some build logs seekayakforum.de (german) boote-forum.de kayakforum.com More Boat Builders: http://www.kudzucraft.com/web/ https://www.thomassondesign.com https://guillemot-kayaks.com/ http://www.yostwerks.org/ http://gentrycustomboats.com/ More Ressources: list of books qajak usa bibliography boote-forum.de; all kinds of boat plans, German duckworks - Kayak building plans index, lots of them. there is also a page for canoes Kudzu Curlew Skin-On-Frame Build Log: Below is a build log. The prototype: This video sparked my interested in building a small water craft. As I could not find a broken down tree to take some fibers from as suggested in the video, I used hazelnut branches which are plenty here where I live. I paddled it once, but it was leaking a lot and had a nasty habit of trying to capsize towards the left side. But that did not matter, it was a floating and I paddled it and that's what counted for me! Wrapped it looked like this: How to chose a boat and construction method: I was looking for a building method in the reach of my woodworking abilities, which did not take too much of time, and had little chances of messing up the shape of the hull after my experience with the hazelnut branch kayak. Roughly speaking, I found these different constructions method for this endeavor. Skin On Frame Kayaks with steam bend rips: This method intimidated me, not only because of the steam bending, but it involves a lot of eyeballing the hull to get it symmetric and shape it in the correct way Described in the book Building The Greenland Kayak, by Christopher Cunningham; actually he has detailed explanations on everything, including the eyeballing part Also used by capefalconkayaks.com Stitch and Glue Plywood Kayaks: This seems also like a pretty fool proof way of building a boat. Plywood forms are cut out, and then, as the name implies, stitched together with e.g. copper wire before reinforcing the joints with glue. As the form is given, I think here are not so many chances to mess up the hull shape. Strip Planked Kayaks: Nick Schade is a boat builder using this method, he also wrote a book about it containing good instructions. It results in beautiful wooden boats, and the hull shape is given by the mold. However I felt that I neither had the skills nor the attention span. https://www.thomassondesign.com is also providing many plans for this method Skin On Frame Kayaks with plywood frames: Here are perpendicular plywood frames cut out from either an offset table or full scale plans, which are then connected by longitudinal. This frame is then covered by a fabric. I felt this was the quickest way of building a boat, and the one with the smallest of course Jeff Hortons Kudzu Craft Tom Yost's SOF boats http://gentrycustomboats.com/ Here is an extensive list of probably most kayak plans that can be found online, of all kinds of construction methods. If I had a proper woodworking workshop and some experience with applying fiber glass/epoxy coatings, I might have chosen a strip plank kayak. But since I did not, it was SOF with plywood frame vs stitch and glue. I settled on the Skin On Frame approach, and there on Jeff Horton's book as it contained the whole process in one book that I could walk through, and it seemed tangible to me. I am intending to use my boat to paddle around for some hours at a time or maybe a daytrip on the rather flat and windless lakes in my area. Also I tried to not have a too long boat, as I wanted to be able to fit it on my car without having at hang over the rear for a couple of meters . In the end there were Kudzu's Ravenswood and Curlew fitting this profile. Here is some discussion about the differences. I went with curlew, as it is a tad bit shorter the whole build is described in Jeff's book. Also there are plenty of curlew build logs on the web, which is probably a good sign. Also I discovered the messing-about.com forum, where I could checkout the most encountered problems. Build log examples are: here then there is Jeff's build log here is a video here is a build with a hatch one here in German So it was decided, I will build a Curlew! I read the book cover to cover. Sourcing Materials: This is how this thread started, so go to the top and find it there the extensive list of where to find materials. Stringers and Gunwales: See the material section for some more information on the lumber used. Using a handheld circular saw, I ripped one straight edge onto the plank as it still had the bark on. After that I used a portable table saw ( it was a Bosch GTS-635-216 ) and the help of another person to rip it into stringers and gunwales. In hindsight I should have ripped it first along the middle, of the plank, as there was the former core of the tree. This should result in stringers that have less offrun of fibers. It takes some planning to have somewhat similiar cross sections on all parts. I probably should have spent more time on that part. After ripping I scarfed all of the parts to extend them about one good meter to have them sufficiently long: Next time I scarf I would make sure them "standing", meaning that the diagonal cut of scarf can be seen from top. This ensures that stays in a straight line. Otherwise you might end up with a warped boat, as I did. I let it dry for a day. If you have the possibility, put it through a jointer. After drying for one day, I used a hand router ( I don't have a router table) to put a 5mm radius on all edges. I started to sand it with an electric grinder, but it was too aggressive. I ended up just sanding once along each part with a 120 grid sandpaper. It goes rather quick, as all four sides are sanded when you grip around it. Plywood Frames: Taking the offsets from the book and drawing it in Sketchup on my computer: Then I printed it with the A3 printer I had at hand. For some parts I had to patch the paper together, which I did by placing it on a glass table with a bright light below. That way you can see through the paper and align it accurately. I cut out the forms from the paper roughly with scissors, then applied a temporary spray on glue to the backside. It makes it sticky, like a post-it note, but can be removed easily. After finding and efficient layout on the plywood, I cut it out using a sabre jig saw ( I have this one) with short, narrow, and fine toothed blades. Switch on the lowest setting of sabring (german: pendelhub), as it makes it easier to cut a small radius. It took about a day and 2 packs of blades for the jig saw. The accuracy I could achieve was certainly high enough for this application. However, since I had it the geometry in CAD already anyway, it would have saved quite a lot of effort to find a CNC and cut it there. It is not so hard and not expensive anymore to do this nowadays. Maybe on the next boat. I also made the coaming from plywood, as it seemed the easiest to me and I had plenty of plywood. After rounding the edges with a router and gluing the upper two coaming rings together: Strongback: As described above, I just used a beam I had at home on saw horses. Was a bit wobbly, but did the job. I made the brackets (dimensions are in the book as well) from scrap wood. Using a string, I aligned the brackets: Framing: Plywood and stringers are ready. I oiled them beforehand, as I thought this is easier. I am not sure about decision anymore. Everything was rather slippery and oily when assembling, and I needed quite a bit more oil because the offcut had to be oiled as well. Only advantage to oiling the finished frame is that hidden surfaces (as the plywood where it touches the stringers) is oiled as well. Decide on your own! Once set up, the frame came together so quick I did not even have a chance to take a picture! I used a japanese style saw to cut the stringers to proper length and fit the gunwales to the bow. This small wood plane was also useful to to fit the gunwales and make the stringers' ends a bit rounder. Here is a method how to fit the surface perfectly. Make sure to fit the gunwale on the bow first, and only then trim it at the end. That way you have another chance to make a good fit by just moving the gunwale a bit to the front . Lashing the Frame: Before starting the lashing, I used a water scale to check if everything was level (level your strongback first!): I used a measure tape to ensure all diagonals were equal, re-measure that all frames are in the right position. I hammered a reference nail into the keel in the middle of the cockpit and measured from there. Also I looked from the end towards the front and check for warps, twists. I checked that bow and stern are right-angled and vertical/horizontal. Everything looked good, so it was time to lash it. Here is a video how to lash. After a few clumsy tries, I was happy with how my lashings looked and so I lashed all joints. It may seem like it will take an eternity, but after a couple of finished lashings the pace will pick up. I took the distance from my fingertips to the opposing shoulder as length for the string. If I couldn't get the straight needle behind the lashings for the tensioning, I changed to a curved needle. NOTE: Many hours can be saved by not binding off each lashing separately and starting anew, but continuing straight to the next stringer in the same frame. Jeff explains it here for his short shot model. This is especially true on multichine boats ( they have even more stringers to give the hull a rounder shape). After finishing the lashing, I took it from the strongback. I don't have a FROG picture, but I serve with a Frame-On-Asphalt picture, in the dark: Disaster! The frame is a mess! After being happy that my frame is finished, I realized there was a corkscrew twist in my frame. It was quite obvious, and skinning that frame would have resulted in a boat that was not going straight. Here is a picture of the stern being level, you can see how it twists toward the right: Here is a picture with the bow being vertical, you can see the stern is hanging 10 to 15 degrees to starboard: Here is somebody with a similar problem. Here is the forum thread with all my attempted fixes, if you are in the same position. Other names for this problem are winding and hull twist. Nothing seemed to help and I was desperate. All distances and diagonals were right, the frames symmetrical, applying torque for a couple of weeks did not do much, using brute force by over-twisting the frame the other way did not do anything either. It was hard to find, because the cause for it could have been anywhere. At some point I was close to repurposing the frame as firewood. So I let it by itself for some time. In the end I realized the port side gunwale had a strange knot and the scarf might have had a very slight angle (that's why i said above that next time I'd have it standing when glueing the scarf). Luckily there was still enough lumber to produce a new gunwale, and after installing it, the boat was noticeably straighter. If you also end up in a seemingly unresovable issue, don't despair! Anything can be fixed, it sometimes just takes more time to figure out or is more effort. Such is the life of the boatbuilder?. Go to forums and describe your problem as good as possible, there are always friendly people willing to give advice. Now it seemed to me that the twist reduced to an acceptable level: Floorboards: Somehow, I still don't understand why, I completly skipped the section in the book where it explains how to loft the frames closest to the cockpit in such a way to allow the installation of floorboards. I think because it says canoe on the same doublepage, so I skipped ahead. Anyway, that's part of boatbuilding as I have learned above. Options to fix would have been to either resaw the two frames, or attach the floorboards by some other means. I went with the latter options, as the first would have required to undo lots of lashings which i did not want to risk now that my frame was straight. So I cut the boards, drilled some large holes into it to save some weight. I rounded of the bottom corners as a small safety feature, so in case the lashings break there is a round corner hitting skin: Filed notches into the frame to keep the lashings from sliding towards the middle: As the floorboards are stretching over a rather long disatnce in curlew they seemed to flex a lot to me, so I decided to add reinforcing beams on the bottom. It will be a bit tight with the skin, but it shouldn't touch it. I put glue on it, then added three screws. I put some weight in the middle of the floorboard when installing it, so it is now slight pretensioned upwards: Here is a side view: Footrests: When installing the footrests, I realized I don't have enough space between the two frames, so I had to trim a centimeter of the locking mechanism, but it shouldn't make a difference. For deciding the height, I clamped a board on the outside of the bottom to mimick the skin, sat in, and tried how high it has to be for me. I figured I want the pressure point on the balls of my feet, below the toes. I fitted some stringer cutoff to fit inbetween the gunwales and the lower stringers, and drilled a hole to lash it in place. The front of the footrest is resting on the next frame, to have something to push against. It's important to be attached strongly in the longitudinal directions, as the force when you paddle is transfered to the frame mostly over your feet. Screws are stainless steel: Skinning the Frame: Once I had a proper fabric, the skinning and sewing went pretty smoothly. My fabric was not shrinkable by heat, so I made sure that is already drumtight after the sewing. Started by having the boat keel up and unrolling the skin over it, making sure the weave follows the keel. Clamping it together on the bottom, so in the middle of the deck before turning it back over. Using lots of cloths pins I started tensioning it: Once it took shape I started trimming the excess. It started to look more and more like a boat! Then came the tedious task. Iteratively going trough the fabric from the middle of the boat towards the ends, opening one pin at a time, putting slightly more tension into the skin, clamping it, and going to the next one. I did this a couple of times until the wrinkles were gone. It's also a good idea to go to the ends and get a good grip on the fabric, and then pull. This will move the fabric toward the end, and on the next pass you get more tension in the skin. Sewing the Skin: I started to sew as suggested in the book, starting from the middle and sewed towards the ends of the boat. I made a small frame and practiced my sewing there. Here are some video tutorials. I noticed that I could put even a bit more tension into skin than with the clamps alone, by biting the fabric a couple of millimeters towards the gunwale, and then pullin the thread tight. Pull and move the fabric a lot with your other hand, this will help to pull the fabric together. Did not take picture of the progress, but here is the finished running stich: The bow and the stern is reinforced by sewing backwards again: After trimming the excess to 38mm ( I had a scrap piece of gunwale that seemed to be a good length), I sewed it with whipstitches to a kind of rope. I used a 25mm reference for the stich length, which made it much more consistent looking. A hemostat or a small but strong and pointy clamp can be useful, so you can take your hands of and take a break. Keep the string always under tension, and wiggle the fabric in the direction of the sew, don't be afraid to push it quite much so that the string because tight in the fabric. It looks neat: One more hint when starting and ending a sew. Leave about 10 cm more string after the stopper knot. When the whiplash is sewed, put this leftover on a needle and push it into the fabric roll. Come out a couple of centimeters away from it. Pull it really tight and cut it flush with the fabric. When the cut releases the tension, it pulls the end back inside of the roll and it will stay there. Now the starting and ending of the sewing is invisible! Here is her bottom: Coaming Installation: NOTE: andy00 has found a better way to install a coaming. It is in one of the posts below. Next came the coaming. I had predrilled the comaing in 10cm distances from the lower side. The lower ring was lashed to the frame to keep the position, and with the upper ring I pinched the fabric. I tensioned it while keeping the pinch strong with lots of clamps. One by one I drove in the screws using a mirror and a socket wrench(something like this) with an adapter to a torx bit. Two thoughts on that. It was annoying and a lot of work to screw fromt he bottom, as it is quite tight. I might just screw it from the top next time as it is much quicker. Just use an electric drill and it's done in minutes. It does look nicer that way though! The other thing I have noticed is that the screws did not really pull the rings together, so there is a slight gap between them now. If ater leaks in when rolling the kayak, I have to find a way to close it. Also, the skin is not held by the rings but kind of resting on the screws. My screws had the windings going all the way to the head ( I had them at home), but next time I would use screws like these below. They would pull the rings together. Keep in mind that it's a different story if you are screwing from the top. Because the skin is held by the screws in my case, I did not want to trim the fabric flush, but decided to stable it to the bottom of the coaming to give it some more strength. In the curves it has to be cut radially in order to be able to fold it back of course. You can also see some slight pull stripes where the screws are located, if you look carefully. But it should be covered by the paint anyway. It ended up looking good: Here is the skinned boat, I am pleased with the result: Backrest: I put the straps to the longest position, held the back of the backrest against the back of the coaming (because this is furthest it will go backwards) and screwed the other end of the strap to where it reached furthest. Made sure that the other side is symtrical by measuring the same distance fromt he front middle of the coaming. There are small bungee cords to hold it upright, for which I screwed small hooks (German: Schraubhaken) into the bottom of the coaming. (I don't have a pictureof the hooks, but here it is with a screw:) Coaming Cover: While I am waiting for warmer temperatures for painting, I made a coaming cover from two leftover pieces of fabric, that are sewed together. I took a piece of cardboard and traced the outside of the coaming on it and cut it out. After tracing the cardboard shape onto the fabric, I made dots in distances of 1.5cm form the shape, 2.5cm from the first dot, and 0.5cm from the second dot. Connected the third dotrow and cut the fabric along it. Now folding the second dotrow onto the first one, and temporarily holding the fold in place with needles. Now sew around the dots (can't be seen now, but you can eyeball it). I used a sewing machine, but can also be done by hand of course. Keep a 2cm hole in this created tube (mine is at the bottom, but it does not matter) where you can feed in a string or a bungee cord. Add a stopper and you now have a cockpit cover. Storage under the roof: I needed a place to store the boat when not in use. Somewhere dry, protected from the elements and the sun, and most importantly where it's not in the way. After thinking about it some time I looked up in my temporary boatyard and realized there is just enough clearance to store it there. In the back there is an box shaped bracket: In the front it is L-shaped. It's quite thight, but it can be brought in from the door and then slided stern first over the aluminium bar towards the end, and then lifted onto the bar of the L-bracket: I was a bit worried that it will start to sag in the bow, as it was extending quite far from the L-bracket. So I added a rubber bungee in the very front to take some strain away. Don't have a picture of it though. I stapled some soft scrap fabric to the parts of the ceiling that I was always hitting when moving the boat in and out of the new storage position. Also I realised there is space for about three more boats . Floatation Bags: Floatation bags are highly recommended for SOF boats, in case of capsize or a skin ripping. Decided from where to where the bag should extend. In my case from the frame behind the coaming to the last frame for the one in the back. Then I measured the circumference at these. Repeat for the front bag. It starts further in the front because my legs take space, so it is quite a bit shorter than the rear bag. I cut these trapezial shape first from paper and then from the fabric mentioned in the materials. The height is the distance between the frames, and the high/low side width is half the circumference at that point. I added a 5cm x 5cm flange to glue in the hose later. If it's not symmetrical the shape has to be cut out mirror on the second piece, as only one side of the fabric can be welded (and it has to be this side on both sides of the weld). Absolute accuracy is not important, as it will inflate and a cm difference will not make much of a difference later. The two parts which are welded together to have to fit together though. I still need to glue in the hose and find a way to plug it. If you want it fancy, there are also one way valves available. Painting the Skin: I used 0.5l of white paint(because white is cheaper than the custom mixed color) that I thinned with 10% of paint thinner for the first two layers of color. Then I put two more unthinned layers of yellow color on the boat, which used the whole 1l of paint. It is fine now, but it could have used another layer of paint. Next time I would buy 1l white and 1l of my color choice for a better paintjob. First I was planning to hang it from the ceiling, but that did not work out so well. Since I was expecting to need 4 layers of paint, I didn't want to wait for the hull to be dry until turning it over to paint the deck, as this would double the painting time. I put some plastic wrap around the sawhorses and just turned it over after painting the hull/deck. It left a small mark, so for the last layer I actually waited. After the first layer of white it actually looked quite nice: After the first two layers of white: Unfortunately some strange roughness appeared after saturating the fabric with color. I very carefully sanded it after drying, but it came back after the next layer. First I thought it were fibers of the fabric that stood up due to the paint, but since it came back after the next layer I am not sure about it . Does anybody know what caused this? The skin lost a little bit of tension due to the painting, but it was not too bad. Some wrinkles were visible, but they have disappeared again. Painted: Deck Rigging: I cut the leather strip from the material list into 8mm wide pieces, and treated them with mink oil which is intended for shoe care, because I had it at home. I did this by hammering a razorblade in the end of a board, and clamping another board offset by 8mm on top, where I then pulled the leather strip through to cut of the pieces. Also to make a grip handle at the bow and stern. Of course I forgot to drill the holes for it before skinning, so I will had to eyeball the hole position when drilling them. In the bow I drilled a little behind the first frame, and in the stern a little in front of the last frame, as I figured this is the strongest point. In the front it was easy to feed trough a rather stiff wire: To the wire I then attached a piece of the polyester string used for sewing. I pulled the wire back out and the string was then inside. On the leather strip I cut the end a little bit more pointy, and used a timber hitch to attach the string to the leather strip and pulled it through. Went through smoothly! (It's a picture of the Stern now). On the stern it was a little trickier, as there is a deck beam blocking the line of sight between the holes. I bound a large loop to the polyester string and pushed it in on one side, then used a thin wire with a small hook bend in the end to fish it out again. Took a few minutes of fiddling around, but it was also quite easy. PUT A DRILL COLLAR ON YOUR DRILL! As you can see here, I damaged the fabric on the inside because I had to drill upwards. Toggles: For the toggles I used a 20mm beech plank that I had at home. I cut a 15mm x 80 mm strip, and drilled two 7mm holes with a distance of 50mm between them from the sides. The darker part that can be seen is where the bark was, which was part of the plank. The long edges I broke with a plane, and the ends I cut roughly with the jigsaw and sanded it a bit. Then I applied a layer of tung oil. They look a little rustic, as intended: As described in the book, I had a 20mm nylon strap where I cut 5cm pieces from with a hotknife. Using a hot nail I burned holes in the ends, and when folded over with a washer and a 3x16mm screw it becomes a nice attachtment for the rigging. They can be seen on the pictures with the toggles above. I started on one side and screwed it in at an 45degree angle, down at half the height of the gunwale. The second one is 50mm+40mm=90mm further to the front. Although this is alright, it could have been a bit more of distance so the tensioning is working better. 1.5" is what is recommended in Christopher Cunningham's book. Robert Morris recommends the width of a paddle. For the other side, I measured from the bow. The two ends of the leather strap I bound together using a square knot and added some superglue to make it permanent. Repeated the same behind the coaming. Here is the fully rigged boat: Keel Strip: to be added Maiden Voyage: As Jeff predicted in his book, I want to take the boat to the water badly by now! Here is the launch post. Here is a picture of the finished boat, not rigged yet: NOTE: This is still work in progress, I am updating as I progress. Questions, remarks, and corrections are appreciated.
  5. I know this an old thread, but are there more experiences with Paulownia wood used in skin on frame kayaks? On this website boards can be bought, although the shipping is quite expensive (they quoted my 85€ of shipping for a pack of board with 2.5m(8.2ft) length, so each would only need one scarf): https://www.ipaulownia.com/en/shop/paulownia-boards/ I explained what I intend to use it for, so they offered to already cut it into the right dimension. Might be an option for people without a circular saw. It is started to be grown in plantations in northern Italy as well, so it should be available easily in Europe in the future. This could really be a good alternative here in Europe, as Western Red Cedar is hard to come by. Compared to my spruce stringers, I could save around 4kg(~8.8lbs) compared to spruce on the fuselage, which is significant.
  6. Hi MadBoat, did you figure that out? I am also interested in building a tangerine, but i can't find any pictures of builds online.
  7. So next time I would make sure that all gunwales and stringers have the same grain orientation on the cross section, and also check that both sides have an equal flex. here is a video about kayak wood selection, I linked the part where he talks about the stringers.
  8. Alright this took me a long time to figure, to eventually I decided to just replace the suspect gunwale, and it reduced the twist significantly. It is not gone completely, but I decided to declare it straight enough for skinning. After inspecting the bad gunwale, I realized there is a scarf at the height of the seat, which was not perfectly straight but shifted to a slight angle during glueing. This must also have caused some misalignment to the rest of the frame while it was still on the strongback, at least that would explain the remaining corkscrewing in the frame. So next step is skinning, hope that goes a bit smoother than the frame ?
  9. Hi! Sorry to hear of your troubles. I am struggling also with a twisted frame as well, but I haven't skinned the boat yet. Was the frame straight before you skinned it? If so, I would guess that when tensioning the fabric one side was pulled tighter than the other, did you notice anything like this? What did you use for skinning? Polyester can be tightened with a hot iron. If you think about it where the twist is coming from, maybe you can counteract this force by tightening on the opposite side? There is also this skinning technique, where the skin is tightened with some tightening sews and only then is sewed shut. If you you in with direction to apply the counteracting force, this could be applied? Just thinking out loud, hope it helps Keep us updated.
  10. @labrat: This sums up my thoughts in one sentence, thanks! English is not my first language. If I look carefully at my gunwales, the port side is nice and has straight grain, but the starboard side has a funny pattern in it behinde the cockpit. One week of applying quite some torque did not help at all, did not try with steam though. Today I spent some time trying to figure it out again with a friend. We tried multiple things, e.g. opening the gunwale lashing in certain frames and bending it out (with a shin), but whatever we tried did not match what we predicted. It's kind of tricky, because there is always translation and rotation (=levering) and that in both directions of the change). One more thing worth mentioning maybe, is that most of my scarfs were not good enough. They will hold becaues they have a neat fitting, but the are not as straight as they could be. Also, all these changes did not have a lot of impact on the frame, which is good as it shows the frame design is rather robust. Thanks for the design @Kudzu! In the end I opened the bow gunwale lashes and planed away a bit of the port side gunwale. This helped a little bit, but I did not dare to go any further as it might skew something else. Anyway, as I am out of ideas proclaim my curlew frame as ready for skinning! As I am out of ideas mostly. If it turns out to not track well, I can still add a skeg to make it go straight. What do you guys think?
  11. Today I check all the frame distances between each other and also with respect to a "zero" point, which is a nail in the middle of the keel in the cockpit. Still, all the distances are symetric. Which makes sense, as I double and triplechecked while it was still on the strongback. Also, the gunwales were always level, and also the frames were vertical when checked with a waterscale. When installing the stringers I always tried to match left and right stringer so they needed an equal amount of force to fit to the frame. So my theory is, that one diagonal opposing pair (e.g. top right gunwale and bottom left stringer) is not so well balanced (one is bending inwards too easily, where as the other is resisting this much more). Don't know though how to find it, and also I don't know what I would do with it if it would fit. Anyway, now I put it back on the strongback and level the stern. Then I measured carefully with a waterscale going forward one frame a time and it seemed like most of the twist happens where there is long distance between frames where the cockpit will be. Doublecheck this by leveling the bow and measuring backwards, and voilà, I ended up in the same spot. Now I applied some torque with some improvised levers and bungee cords as shown on the picture, and wait for a few days. @lattenkracher: Doublechecked, was fine. @Kudzu: Thanks Jeff for the hints, this brought me in the right direction. Actually I now think it was the faulty part is one stringer that was not scarf in the straightest way, which is causing the bend. Let's see how it goes, if it does not settle (my garage is about 10°C or 50 degree fahrenheit) I can still try a warmer place, or pour some (hot) water over it. If somebody has a similiar problem, this is what I found: Here it explains how to check and then just use force to straighten it. straightening an old canoe some more discussion This is what I have tried: Are all the distances between frames equal, are the frames vertical (check with a waterscale)? Also check looking from top for symetry of each frame. Did you notice that some stringers took more/less force than others to bend them into shape? Check the scarf joints! Are the extensions straight, or point down/up? Where is most of the torsion happening? More in the front, the back, over the whole boat? Thanks
  12. Hello, the title explains it already pretty well. On the strongback, the frame was level and square. Now I took it out of the strongback and it developed a rotation along the long axis. I took some pictures to show it. I can not really tell what is causing the twist, my guess would be the bow. Stringers are spruce and the weight of the frame is 8.4kg, overall it feels rather flexible. I tried to fixate the bow and rotate the stern clockwise, and it helped a little bit but I think it will go back. Is there a way to fix it? How do I find out what is causing it? Thanks!
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