Small Multi-Hull for Beginner

Discussion in 'Multihulls' started by larkinja, Mar 14, 2016.

  1. larkinja
    Joined: Aug 2010
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    larkinja Junior Member

    Hi everyone. I am hoping someone can't give me some suggestions. I am interested in building a multihull. I have never built a boat before, but I have a huge fascination in doing so. I have owned a multitude of boats in my life.

    I am always trying to find projects I can work on that help me learn something new. Since I have never built a boat I would like to do something on the easier side the first time around. I know very little about hull design. I am very handy, and I work on my own boats all the time. I am familiar with wood wood working, fiberglass repair, epoxy, motors, electronics, etc...

    In a search for plans I stumbled across this boat.

    http://www.teamscarab.com.au/5.6cat/design.html

    I have a large CNC router and am wanting to utilize it in this project. Hense I am looking for plans that may have files available to cut the kit. I have been mainly looking at kits that use plywood and epoxy.

    I also do not want to build a sailboat, well at least yet. I know nothing about sailing, so I would like to stick with something I can put an outboard or 2 on.

    My ultimate goal is to find something small and learn from, then move on to something a little bigger down the road. Well, if I find I enjoy it, but I suspect I will.

    So if anyone has any thoughts or references, that would be awesome. Again, looking for a plan I can learn from, not try to design my own...at least not yet. .:)
     
  2. jamez
    Joined: Feb 2007
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    jamez Senior Member

    Looks like one of the Kendricks has already been built as a powerboat (you could always add the rig later) and plans and dxf files are available and cheap. or in a similar size how about.. http://www.ikarus342000.com/ECOmotorboat.htm
     
  3. rael dobkins
    Joined: Jul 2015
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    rael dobkins Senior Member

    Hi, here's pacific Proa WHY NOT? I built him in 5 days and went sailing.
    https://youtu.be/ZEB61zqqfns

    this is how U build him. just youtube films about stitch and glue, then all you need is a jigsaw and a few other bits and bobs.... I got tangled up i a bigger proa for 3 years now... CRYSTAL CLEAR will finally be in her element this summer. BUT what I"M saying is that if I built WHY NOT? long ago, CRYSTAL CLEAR would have been sailing long long ago....
    BOTTOM LINE, the smaller U start the better.
    here's how U build WHY NOT? any questions? just ask.
    https://youtu.be/jACkJPf7yKY
    Good luck
     
  4. larkinja
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    larkinja Junior Member

    That's a neat boat. Any idea if anyone has a build log on it anywhere? The BOM looks fairly basic. Can't be to bad if it fits on one page. :)

    I didn't see anything about DXF files being available. Do you have experience with this person?

    Thank you!
     
  5. larkinja
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    larkinja Junior Member

    That's pretty awesome. On the water in 5 days! This might be a little more simplistic than I am looking for, but thanks for sharing. BTW, how the heck do you steer that thing? :)
     
  6. Richard Woods
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    Richard Woods Woods Designs

  7. larkinja
    Joined: Aug 2010
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    larkinja Junior Member

    I was actually looking at your designs last night! I do like yours as well. I had been looking at the folding hulls. Trying to decide on the complexity of a first build. Would you say your boat is suitable for a first time build? It's really easy for me to get carried away and bite off more than I can chew. It's not really a budget thing, more of an experience thing. I'm not much into small boats these days, but starting with something small seems the best way to learn. I don't really have a use in mind for this boat, it's just more about learning something new, and hoping maybe my son will enjoy doing it with me.

    Do you have DXF files for your plans? Any plans I buy will need to have the files so I can cut on my CNC router. Or at least without spending hours doing it, be able to pull them from an electronic plan. This build is about learning to build the actual boat. I don't want to spend hours with a jigsaw cutting wood. Besides, you can't get more accurate than a CNC machine. I have 63" x 145" of cutable area on my machine so I should be able to cut any piece I need.

    Thank you!
     
  8. Richard Woods
    Joined: Jun 2006
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    Richard Woods Woods Designs

    The Skoota has dxf files for most parts.

    However I would advise against CNC routering anything apart from the bulkheads and initial cuddy "box" because you want all the parts to fit and thus be watertight.

    Generally boatbuilders tolerance is about 2mm (say 1/16in). The CNC machine will cut exactly, so you could potentially have 2mm gaps between the cut parts when you assemble them. Making a 20ft hull to a 1/16in accuracy is pretty impressive even for a professional.

    Of course you can do it by "stitch and glue" and allow the epoxy and tape to fill any gaps. But one problem with that is that the panels then get very hard to man handle. One reason for having ply sheets at 8ft x 4ft is that they are man handle-able. Imagine moving a piece 20ft x 4ft x 1/4in by yourself. I find stitch and glue slower and more expensive than timber framing when making easy joints. I only use it for double bevelled joints.

    As you are a beginner boatbuilder expecting precut hull side panels to fit exactly would seem too ambitious. Better to make the boat to fit the parts already made. That's what I do, but then I am not a boatbuilder.

    The Skoota design is all flat panels, no double curves at all. You can build it all in parts and join it together at the end. We built ours in a 16ft x 18ft garage (which had household "stuff" in it as well). First we built the cuddy, then each hull separately, as they fitted in at an angle. We were able to assemble the whole boat, just, in the garage, the hulls stuck out but by then they were watertight.

    You could start with the cuddy, basically a simple box. If after building it you decide that it is too much for you, or that time is running short you can get a local boatbuilder to make the hulls. In fact that is what we did with our second hull. To save time we got someone 150 miles away to build it for us. He delivered it on the top of his car (!) - not bad for a 20ft hull! See photo here and in the 2010 year review on my site

    I like to build my own boats because then I can iron out all the bugs and more important I know how its built. I don't just supply plans and expect builders to do the experimenting for me.

    Although we used our Skoota 20 for a couple of years cruising in the PNW (longest trip was to Princess Louisa inlet, see videos here https://www.youtube.com/user/WoodsDesigns/videos ) we never really finished it. Hence the grey primer paint and no windows. That was because we had presold it to someone in Belize who wanted a "part finished" look to reduce the import duty.

    He came to pick up the boat with his flat bed trailer on a Tuesday afternoon. We fitted the trailer supports to his trailer on the Wednesday, loaded it that evening and he left first thing Thursday morning. A week later we heard he was at the dock in Florida ready to ship it to Belize.

    I hope that helps, if you want to discuss the design further maybe it would be better to email me direct

    Written on board my Skoota 28 in the Bahamas, hence the delay in replying

    Richard Woods of Woods Designs

    www.sailingcatamarans.com
     

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  9. larkinja
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    larkinja Junior Member

    Working from the Bahamas doesn't sound to bad!

    Well that is kind of a bummer. I was somehow under the impression I could router out the parts and it would all fit together. So I have seen many kits you can purchase that are routed on a CNC machine and come to you with pieces ready to assemble. I would just assume then that these just have more engineering done to them to assure they fit? Maybe mistakenly, I just assumed the plans that come with cut files would be the same.

    We can discuss more over email.
     
  10. Stumble
    Joined: Oct 2008
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    Stumble Senior Member

    Lark,

    Think of it this way, it is possible to build a boat and have things lineup exactly... But it takes a very high degree of wood working skill. About the same as building a house and having every wall exactly plumb. Technically possible, but even a slight variation in one place can mess up something else down the road.

    Building a boat to these exacting demands is even harder than building a house to be perfectly level. By cutting everything out on a CNC machine you eliminate the ability to fudge it a bit. While cutting them by hand allows a bit more freedom to oversize something just a tad to fit the available space. The alternative of course being to rip the structure apart and close the gap by 1/32 of an inch.
     
  11. Richard Woods
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    Richard Woods Woods Designs

    Actually, even for me, cutting and fitting to shape doesn't take long at all. What takes the time is finishing the boat, ie filling and fairing and then painting. Thats why I estimate build times to "ready to paint" condition.

    We built my Duo dinghy in 2 days, but it took much longer to fill/sand/paint. We also built my 14ft sailing dinghy Zest in two days, but I have still to paint it. And I know that will take a lot longer. I hate filling and sanding!

    I find that the glass tape/epoxy joints take much longer to fair/fill than do conventional wood ones. So what you might save in one place you'll lose much more in another.

    Yes there are kit boats available, and have been for decades. But they do tend to be stitch and glue boats, as I said before. For example my Duo, Tryst, Pixie, Quattro 14, 16, Zeta, Stealth, Zest are all stitch and glue and you can indeed CNC router those out. They are all small boats, under 16ft so panel sizes are manageable.

    Richard Woods
     
  12. jamez
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    jamez Senior Member

    I meant the dxf files are available for the Kendrick, which is basically a stitch and tape type, which as Richard points out, is probably more appropriate for a full on CnC. I don't know if Bernd provides them for his designs but you could ask him, he has a forum on yahoo you can link to from his website.
     
  13. larkinja
    Joined: Aug 2010
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    larkinja Junior Member

    Okay so that all makes sense. I think I am going to do some experimenting with vacuum infusion. There are some plans out there that use this method with building some simple molds. I think I am going to mockup a mini version of one and start playing with these methods. I think I can mockup the mold pieces on my CNC and glue them together. Just need to start researching where to get these infusion materials around here. Anyone have any experience building a small power cat using this method?
     

  14. ricardoribeiro
    Joined: Mar 2004
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    Location: Brasil

    ricardoribeiro Junior member

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