Looking for Cat plans. Suggestions?

Discussion in 'Boat Design' started by Tropical Sailor, Jun 4, 2014.

  1. Tropical Sailor
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    Tropical Sailor Junior Member

    Great site. I had downloaded some simple skiff plans from a UN FAO site before, but I´ve never seen these.

    Thanks,

    Andy
     
  2. Petros
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    Petros Senior Member

    I guess you do not know what I am used to. on many trips I am sleeping in the back of a car in a sleeping bag. Anywhere that is safe to stay would be fine with me, it would be better if I did not have to bring a tent and sleeping bag (more room for tools and boat building supplies in the luggage). I do not particularly care for hotels, a spare bedroom or even a couch is fine with me. I already checked the round trip fare from Seattle to Cancun, only about $600-700. It would be 5 day drive if I wanted to drive it.

    This is actually starting to sound like an interesting challenge. I am an engineer by profession, but have designed and built 20 or more small boats, many of them skin on frame. If we can get use of the plans for a boat the size you want, I can design a skin-on-frame structure that is suitable for the intended use. It appears you have suitable lumber on hand (or can have it cut to the size we want), I just need to find out the properties of the type of wood you have available, and I can design you a strong and safe structure. The Amatasi 27 is a good design for building with local materials, it also looks more like a "native" or tropical type boat design, so it would be suitable for giving tourists sailboat rides in with appropriate seating. And it would still be suitable for fishing and light cargo delivery as well. It might be a bit heavy for hauling up on a beach, we could scale it down to 20 to 24 ft. We would also want a rig design that can be made with locally available materials, no need for fancy Harkin hardware on this boat.

    Perhaps Richard Woods could give use some lines and a sail plan for a good catamaran, and I can design the structure and details suitable for "primitive" construction methods (basically hand tools, lashings and simple fasteners, no adhesives, no tooling or molds). I will be seeing Richard in Port Townsend in September.

    Are stainless or silicone bronze screws available in your area? Any type of heavy woven fabric 12 to 20 oz/sq yd would work, but polyester or nylon is the best. there is a local supplier here in Bellingham, I will see if he can give us a price break. If I drive I can bring some of the materials with me, like a roll or two of fabric and suitable fasteners.

    what wood working tools do you have available? It seems most could be purchased in Cancun. Are prices higher there than here? I can get used wood working tools cheap here.

    It also occurred to me that if we can work up a budget, conceptual plans, etc. this might be the kind of project suitable for crowd funding as a charity project. if we put a proposal together with nice pictures, a rough business plan for the locals, and a reasonable budget, this is the kind of charitable project that might inspire many people to donate money for costs and materials. I do not mind volunteering my time, if I can get some of my out of pockets costs covered too than this would be very workable.

    what is the best time of year to visit your area? (I do not mind rain, but extreme heat and humidity are not exactly fun, though I have spent much time in Austin TX with my daughter in July, so I know how to deal with it). What is the nearest town to you? What is local transportation like? Would drive a car there be useful for also having local transportation? to get tools and supplies.

    If I drive I thought about buying a used car for the trip, to bring materials with, and than sell it there and fly home. that way I can also perhaps gather up wood working tools here and leave them behind. Is that a reasonable thing to do? what are the regulations about selling a US registered car there to a local?
     
  3. Petros
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    Petros Senior Member

    I happened by Bellingham this afternoon and the fabric supplier happened to be in late today so I got to talk with him about what he has available.

    he has some odd 10 oz polyester he would sell a 100 yard roll of for only $300 (that is really low cost), he wants to unload it. it is odd because it has different weight threads going in the different directions, so it is stronger one direction than the other, but it could work. I got a sample to play with. 100 yards is enough to make six large beach cats! Shipping a whole roll to you would likely cost more than the fabric, though I could bring it in the back of a car if I drive.

    He also has some really tough 14 oz polyester he will sell at a great price of $9/yard, shipping enough for one catamaran to Mexico would only cost about $40. So this fabric skin could be shipped to you for about $200 for enough fabric for one catamaran. Or I can bring it in my luggage.

    The 10 oz fabric would be a good weight for a smaller hull, 20 ft or less, but would likely have to be replaced more often, like every 3 to 5 years of use. the 14 oz fabric would last a very long time and be very tough and durable, I suspect a service life of perhaps 8 to 10 years or more with a fresh coat of sealant every year.

    Both of these come in 72 inch width, so a center seam is not necessary.

    See what you can find locally. Polyester or nylon, uncoated (any color) are the best choice, heavy cotton duck or canvas can also work well but will have less service life.
     
  4. messabout
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    messabout Senior Member

    Petros and Tropical Sailor, you have a really great deal going there. This has all the elements of high adventure along with an equally, or even more, important service to some of the indigenous people.

    Aside commentary and questions...I do not mean to derail an exceptionally worthwhile thread. Petros, the SOF super booster, has gotten me to thinking seriously about the method. For lightweight and overall cost, it has few, if any, rivals.

    Questions..............................Does standard dacron (terylene if you are a Brit) sail cloth qualify as a suitable skin material? Please tell me what is "ballistic" nylon. We are learning here are we not? There may very well be a lot of tired and retired sails that could be gotten for free.....just thinking about possibilities and economics.

    My Spanish vocabulary is limited, consisting mostly of profane words that the mischievous kids taught me when I grew up in Ybor City, the main Hispanic part of Tampa. I would entertain the thought of participating as a grunt boat builder/helper in a project like this. I am, a pretty good craftsman who has built a slew of boats. But never a SOF except a Mead kit kayak way back in the dark ages., like in the 50s when I was a mere tad.
     
  5. Petros
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    Petros Senior Member

    I have thought about old sail cloth, and it could be made two work, but it does have disavantages. It is already sealed with a coating, the fabric weight is not very high, and worst of all it was designed not to have much stretch so getting over a hull without too many puckers or wrinkles will not be easy (but it can be done with extra seams and darts).

    I am not sure I have seen Dacron (polyester) sail cloth much heavier than about 4 to 6 oz, certainly not as heavy as 12 to 14 oz. So durability would be a problem, but I can make it work if we get one for free. However, it might be better to use an old sail as a sail, rather than a hull covering. If we have to palm tree fibers could be woven into a tight mat or fabric and than seal it up with tar. It can be collected off the beach and melted in a pot and brushed on. The Irish did this on their canvas currahs, which they used in the north sea.

    Balistics nylon is just like nylon pack cloth, but with a much heavier weave. Very tough and druable, now used in soft luggage. It could work well as a hull skin but the size of the weave will make the surface rough unless you put a lot of layers of paint on it to fill the weave.

    Several advantage to skin-on-frame, one is minimal amount of materials used for the hull, and the other is massive labor savings, and much lower carpentry skill required, to make the hull water tight. Consider the amount of labor and skill it takes to created a plank on frame hull water tight. this problem goes away when you are just covering the whole hull with heavy fabric that gets sealed, not unlike fiberglass and resin.
     
  6. upchurchmr
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    upchurchmr Senior Member

    Messabout,

    Sail cloth is already "heat set" to insure it does not stretch out of position, in addition to be coated like Petros said.
    Normally Dacron is used un heat set so you can use heat to shrink out any wrinkles.
     
  7. messabout
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    messabout Senior Member

    Got it. We need to have the ability to shrink the skin before sealing.

    The heat process for sailcloth and some other textiles is called "calendering". Ballistic nylon turns out to be what I have called By another name. I have a roll of the stuff up there on a high shelf along with some nice new 8 ounce sail fabric. The nylon has a water resistant finish on one side, so that is not the right stuff.

    ( for several years I operated a substantial sewing factory that produced luggage, handbags, backpacks and such. We used Sunbrella, leather, vinyls, sail cloth and a variety of other fabrics. thats where those fabrics came from)

    Oh well, never mind. I will get the right stuff if I discover that I am compelled to build a small SOF dinghy.

    I am looking at all those bent ribs in a conventional SOF. Looks like a lot of steaming, burnt fingers, and language not fit for Sunday school to me. That makes me wonder whether the Platt Montford geodesic scheme has sufficient merit.
     
  8. upchurchmr
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    upchurchmr Senior Member

    Messabout,

    The books, videos I have seen about steaming the ribs all suggest that it takes a little to set up a system, but after you understand it and have everything ready, steaming and positioning takes very little time.
    The alternative of course is to go to yostwerks.com or gentrycustomboat.com and use a lot fewer bulkheads of marine ply, with heavier stringers.

    I keep thinking about doing the steamed/ bent rib type construction, but haven't taken the plunge. If you do please post your learned methods. So it is not so hard for me!
     
  9. Tropical Sailor
    Joined: Sep 2013
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    Location: Yucatán, Mexico

    Tropical Sailor Junior Member

    Petros,
    Sorry I couldn´t respond faster, but I went to Merida (the state capital) this past weekend to visit some friends. I wish I had seen your post before I left because Merida would be the best place to check on prices of cloth. (And probably hardware too) I really didn´t understand the SOF process until I read these last posts. I thought the cloth had to be some special cloth made for this purpose. I didn´t know it could be regular cotton cloth for jeans or whatever. I suppose old fashioned canvas would work. It’s tough and heavy. Merida used to be an important textile producer. The fiber and products made of henequen used to be exported all over the world from Progresso. I have a guayabera shirt made from its fibers. It is coarser than cotton or linen. It used to be used to make rope, like jute. There are still many ancient henequen plantations (Haciendas) here in Yucatan. Maybe we could find a source of coarse cloth cheaply, as it is a local product. But, I´m still not sure about the treatment or sealing process. What do you use to seal the cloth? It can´t just be paint can it?

    Andy
     
  10. Tropical Sailor
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    Tropical Sailor Junior Member

    Messabout,
    Thank you for your offer and you are more than welcome to come. As is anyone who would like to contribute to this project. I foresee myself working on this for the next 2 years at least, so anyone who wishes to come and help out would be welcomed.
     
  11. Petros
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    Petros Senior Member

    Great to hear from you again, I figured you were occupied for a few days.

    I know of many people that drive through mexico, and down to countries south of Mexico, I was only thinking of driving if it would save money to bring materials and tools with me, but that does not sound necessary. if we can get suitable bronze screws, and that local fabric, I think we may have everything we need. Lashing cord I can fit in a suitcase. That local fabric sounds very interesting, and very well suited for this kind of project. It is just as well we use as many locally supplied materials so they can keep building these kind of boats after we go home. A table saw is really useful for ripping stringers and making battens, but a good circular saw mounted to a the bottom of a plank of wood on two saw horses makes a workable table saw.

    I do not want to complicate the trip if selling a used car there can result in legal complications. I have funded other trips by buying a fixer, repairing it and than driving it cross country, and selling the car at a profit when I was done with it. But I do not want to risk getting an extended stay in "the big house" while the local authorities are calculating how much they can shake me down. There was a local guy visiting his daughter and son in law in Arizona, and they went across the border for a day, Granpa spent almost 3 months in several jails because he was naive and ignorant enough not to realize they were just looking for a little "tip" to release him, the family spent some $20,000 with equally crooked Mexican lawyers, who were also benefiting the longer the locals keep grandpa in jail. It was all over the local news, I wanted to call them and tell them this could have been over that first day if they just gave the locals their "bite".

    This sounds like a fun "working" vacation, winter would be good for me anyway. It is cold, wet, dark and sometimes slushy/snowy around here in November and December, and my business is slow than anyway. So spending 2 or even 3 weeks down there actually is sounding very nice. I also asked by wife, and no way is she going to let me go without her coming along. She actually once taught English as a second language to immigrant groups when we used to live in the Los Angeles area. Her Spanish is rather rusty by now, but I am sure we can find something for her to do while we do "guy stuff", like butchering wood, and building boats and similar stuff. There is no better way to waste time than messing about with boats, you can actually fool yourself into thinking you are actually doing something useful. In this case we actually may be.

    There are a number of ways to seal the fabric, collecting tar off the beach, heating it and paint it on the fabric. Any tough oil based paint works well, it has to be recoated every season, cheap and avilable. I have also used Acrylic paint, cheap and easy clean up, but it does not have a lot of abrastion resistance so it has to be kept off the sand, or you retouch it once a week or so, but it works and it is cheap. there are a number of two part resins that also work, but they are toxic and expensive, I would go with what ever water proof coatings we can find locally. Usually you prep the fabric by cleaning it with water and let it dry out good in the sun (where I live, in the winter, that means heat lamps), and than thin the first few coats to get good penetration, than up to 5 or 6 more coats at full strength. that will make a tough, flexible and durable finish that is easy to apply additional coats as needed. with oil based paints you also can get nice bright colors too.

    Also, about the sailing rig? Do we have sail cloth available? Used sails perhaps? I have seen those crab claw rigs but do not know how well they work. I have experimented with a simple, modified junk rigs and have been real impressed with how easy it is to make an efficient and controllable rig. the forces on it are low so low tech materials work well too, minimal amount of hardware and rigging required as well.

    The tahiti wayfarer would be a perfect size, with a single crab claw or modified junk, it would be a great project that we could build in about 2 weeks of daily effort using skin on frame. Particularly if we can have all the lumber cut to size (stringers and gunwale stock, etc) before we arrive.
     
  12. SamSam
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    SamSam Senior Member

    I'm not sure what you're looking for-the posts are too long to read and the basic idea seems to shift around.

    I don't know if these plans were put forth or even if they are pertinent to the discussion.

    I think there were two other books by the same organization, flat bottom boats and bigger trawler type fishing boats, but as per usual with a top heavy publicly funded bureaucracy, good look finding them.

    http://www.fao.org/docrep/007/y5649e/y5649e00.HTM

    Never mind the witty sarcasm, I found a few of the sites...

    https://archive.org/details/fishingboatdesig034778mbp

    https://archive.org/details/fishingboatdesig034823mbp

    Here's a thread that goes with it, where the plans are modified for different build methods...

    http://forum.woodenboat.com/showthread.php?80503-FAO-Fisheries-boat-designs-%F8yvind-Gulbrandsen

    Here's the organization with contacts, sales offices, etc...

    http://www.fao.org/docrep/018/i3436e/i3436e.pdf

    Here's what you want, various third world outrigger canoe
    and catamaran plans (on pages 3 +4) but they won't open for me, you might have better luck...

    http://www.spc.int/coastfish/en/publications/technical-manuals/boats-a-safety/boat-plans.html

    Part way down the page here is a vague description of a 16' catamaran from India...

    http://www.nzdl.org/gsdlmod?e=d-000...0&cl=CL1.6&d=HASHfc8d613128f6e253a7fd93.4&x=1

    I believe there are a number of resources for assisting third world people doing what they have to do, including building boats etc. and utilizing what they have on hand, which is not much. I'll bet even Mexico has some, you should hunt up a humanitarian organization there and ask them.
     
  13. Tropical Sailor
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    Tropical Sailor Junior Member

    Thanks, SamSam

    Thanks, SamSam.

    Sorry it´s taken so long to respond. Yes, I have seen fao boat plans. Actually I downloaded all the pacific Island boat plans. Even those that are not cat or proas. I´ve also downloaded many of their (fao) documents dating back to the 60's talking about the need for sail powered fishing and transport craft and some programs financed by charitable organizations to help teach these skills to the locals.

    You said, “I'm not sure what you're looking for-the posts are too long to read …” Yeah, sorry about that. Then you said, “… and the basic idea seems to shift around.” No it hasn´t. Petros was extolling the benefits of Skin on frame contruction. I doubted its practicality for off shore sailing and fishing. He insisted it was a perfect construction method for my project, so I said to him in jest he should come down and build one as a seminar for these young people and prove it. To which he agreed. But that hasn´t changed the focus of the project at all. I´m currently awaiting Richard Woods reply to see if he will provide the plans needed. If not I have made some slight modifications to some of the FAO fishing cat plans that might work.

    Thanks,

    Andy
     
  14. Petros
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    Petros Senior Member

    Nice to see you back on the forum Andy,

    Another idea occured to me if you are willing to give this a try. If I can colaborate with Richard or any other compatent catamaran designer to get some hull lines and a sail plan, I can work out the structural details here and than actually do a test build first. Than I can give it a good shake down here, work out sequence and resolve details and get an accurate bill of materials worked out. And once I get it on the water I can also see how it all works together and work out any design changes. Always with any new design/build/experimental project there are always details you would do differently if you build it again. This would allow me to sort it out here and give it some good shake down trials long before I show up there.

    It would not cost me too much to build a 21 ft long x 10 ft beam skin on frame catamaran, I can use a plastic tarp or tyvek for a test sail (I think I can do with local materials for about $300-400). If it works out well, and I do not want to keep it, than I can always sell it for more than my materials cost. I think this is a good size for your crew because it will give enough room for perhaps six passengers (tourists) plus crew, or a fair amount of cargo on the 5' x 15' deck. This size can also be hauled out up on a beach or ramp with 4 healthy crew members without a trailer or a lift, and without taking it apart. The larger size you were considering, no matter what construction method you use, would not be practical to muscle out of the water without taking it all apart first.

    Doing the build here would allow me to know exactly what tools and materials we will need, and get a better feel for how long it will take to build. I am reasonably certain, with some willing assistants, we can get it built and sailing in under two weeks. I can do the test build in the fall, and than send you detailed materials lists for you to accumulate locally there, and than I was thinking January would be a good time to come there and show you all how to build a durable, seaworthy skin-on-frame "native" catamaran. The weather should be agreeable and my own business here is usually pretty slow until March anyway, it is the perfect time for me to take off for a few weeks.

    how does that sound for build plan and time table?
     

  15. Tropical Sailor
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    Tropical Sailor Junior Member

    Hey Petros,

    It´s good to hear from you. Your plan sounds great. I really appreciate all the work and time you´re willing to invest in this project. It kind of restores your faith in humanity to see someone who cares about people less fortunate, even though you´ve never met them. If you want to speak to Richard or any other designer, that´s fine by me. I just heard back from Richard today and it looks like my “plan” budget is going to be occupied with plans for the Gypsy. Richard says his Acorn and Janus are not appropriate for building with strip planks. And he also says they would not carry the needed load of 6-8 passengers for a water taxi or day charter. Perhaps the Acorn would be appropriate for SOF because of its light design. But, I don´t think Richard would endorse “skin on frame” for his designs. Maybe I´m wrong. But if he doesn´t, we could build your project (use whatever plans you feel are most appropriate) with the boys first and it would be great practice for them. After that I could work with them on the Gypsy project. Who knows, after your demonstration we all might become SOF converts. :)
    Andy

    P.S. Can you recomend a web site I can look at that describes in detail the process of SOF building? I haven´t been able to find one yet. General info, yes, but fotos with details, no.
     
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