Inflatable catamaran build help

Discussion in 'Multihulls' started by Dvorocks, May 27, 2012.

  1. Dvorocks
    Joined: May 2012
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    Dvorocks Junior Member

    Im looking for ideas on what material to use to build the deck for a 17 ft inflatable catamaran.. The main deck is going to be 12 ft long and 7 ft wide..
    This boat is going to be portable so I'm lolling to build it really lite wieght
    My first idea is to build it from 2 inch PVC pipe.. Build a things with it and was happy with its strength and was def not to heavy.. Then I want to cover it with marine plywood
    Like to hear some thoughts but don't be to rough on me
     
  2. John Perry
    Joined: Nov 2003
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    John Perry Senior Member

    A deck 12 foot long and 7foot wide does not seem compatable with the concept of a portable inflatable boat! Are you thinking of making it in sections that clip together, or maybe fold up?

    For a light stiff panel like that a good option is carbon fibre reinforced epoxy skins on a core of honeycombe, eg. nomex, or possibly a good structural foam. I dont see how 2inch PVC pipe is going to help you much, but perhaps I dont understand what you have in mind. Marine ply may be an option, but relatively heavy. You would probably want to stiffen it with some longitudinal stiffeners underneath. Intersting trade off between the thickness of the ply and the spacing and section dimensions of the stiffeners, I mean to look at that with FEA for my own current boat design project. Such analysis has certainly been done for metal structures.

    I have seen a commercially produced inflateable catamaran of about that size, it had a trampoline deck and the hulls did not look to have enough bouyancy to replace that with something too much heavier and still maintain bridge deck clearance. In fact, low bridgedeck clearance looked to be a weakness of that particular craft, but perhaps you are building from scratch with more bouyant inflateable hulls?
     
  3. Dvorocks
    Joined: May 2012
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    Dvorocks Junior Member

    Thanks for the reply.. I guess I probably should have been more detailed
    I'm building the boat around a set of dib inflatable hulls that are 17 feet long
    Dib boats are very durable and are used in many military applications
    The plan is to build a 7 ft wide deck but 2 feet on each side will curve over the hulls and will be used to attack bench seats.. Right now I'm planning on framing it with PVC pipe then using either marine plywood or a product called advantech.. I'm very familiar with both and think I can make a sturdy boat on the cheap..
    I'm open to suggestions but not looking to spend a lot of time or money...I want to use it asap. My plan can be built for less than $400 and done in a day or 2
     
  4. spidennis
    Joined: Feb 2007
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    Location: south padre island, texas

    spidennis Chief Sawdust Sweeper

    a white water river raft? a cataraft?
    they use aluminum tubes with bolt together fittings.
    think hand railing components.
     

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  5. Petros
    Joined: Oct 2007
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    Petros Senior Member

    PVC pipe has poor structural properties, do not use it. Simplest thing to use is alumnium tube, has a good strength to weight ratio, but it is pretty costly material.

    If low budget is your motivation go with a light weight wood frame. YOu can laminate doug fir or southern pine (both very strong woods), and create box beams that are held to the hulls with bungee cords. By being clever you can make them easy to assemble/disassemble for transport without too many small parts (screws, etc.).

    Go look at websites with wood catamaran to get an idea how to detail them. Woods Design has some great and simple to build beams and attachment details.

    Good luck
     
  6. Nnnnnnnn
    Joined: May 2012
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    Nnnnnnnn Junior Member

    Check gik.fordak.ru
    You will find all kinds of inflatable catamaran designs, including boat with partial PVC-piped frame.
     
  7. moab_hill
    Joined: Aug 2012
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    Location: Utah

    moab_hill New Member

    I worked with the DIB 17' mini snout for over 10 years....modded a couple of DIB aluminum frames, & the same with their 24' tubes. My experience is using these boats on flat water and whitewater on the Colorado River here in Utah..
    We hung single and twin 60 hp on them.

    An aluminum frame of DIB design is what you need..made out of aluminum sheeting and some square and round stock.

    Just picked up my own mini snout a month ago.:D
     
  8. Roger Six
    Joined: Aug 2012
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    Roger Six Surge Protector

  9. DimitriW
    Joined: Jun 2013
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    DimitriW Junior Member

    I have build an inflatable catamaran with 60 mm aluminium tubes and tubeclamps.
     

  10. Gunnar
    Joined: Jan 2007
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    Gunnar Junior Member

    I'm doing a small catamaran for paddling and rowing.

    May I ask of any of you who have been on this path before can tel me what quality and weight of PVC is suitable for making inflatable hulls in 15-17feet range?

    I have understood density if the weave can also be different.

    Any advice or pointing to good information are greatly appreciated.

    Feel free to respond in my new tread if this one is to old to resurrect :)
    http://www.boatdesign.net/forums/ma...latable-catamaran-hulls-53968.html#post747137

    best regrads Gunnar
     
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