Inflatable boat construction

Discussion in 'Boatbuilding' started by odysseus, Jun 8, 2006.

  1. odysseus
    Joined: Jun 2006
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    odysseus Junior Member

    Good advice, I hadn't thought about the stretch. You are right about the seam tape, not only for the wicking of air because the polyester fabric is not "wetted" by the urethane. Also, wherever the edge is exposed water can get in. I see two risks due to this: Water freezing to ice, and salt crystal growth (which has a similar effect as ice, but requires repeated exposure to salt water followed by complete drying in many cycles). Thus, seam tape seems necessary at least on the outside.

    Any recommendation where to get it from?
     
  2. Sealion
    Joined: Apr 2003
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    Location: Northumberland U.K.

    Sealion Glue Sniffer

    Yes, check the stretch carefully. For example,the fabric I generally use will stretch aprox 0.6% along the weft and at the same time shrink by 0.1% along the warp when inflated to working pressure (2.5 - 3.0 psi)

    With the size of tubes you intend to build, and the width of your fabric, you can cut all your seam tapes from the edge of the roll. It is advisable to cut the selvedges off any way as these edges cannot be guaranteed to be straight. For seam tapes that do not require tensile strength (i.e inside tapes over overlapping joints) I cut strips off a sheet of 1mm neoprene without a textile backing. This gives a very stretchy tape ideal for sealing the cut edges around the insides of tailcones etc. As E Hanson has said. some fabrics are prone to wicking air through the textile backing.
    One tip- before you apply solvent or adhesive to tapes without a textile backing, stick them down onto masking tape or they are liable to curl up.
     
  3. Sealion
    Joined: Apr 2003
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    Location: Northumberland U.K.

    Sealion Glue Sniffer

    Baffled?

    The baffles between compartments should not be tight, but allow for differing pressures in adjacent compartments to be equalized, by moving one way or the other. I use cone shaped baffles as they are easy to construct and fit. The baffle has to be glued on both sides, otherwise it will peel away from the inside of the tube if the pressure is greater on the unglued side. I will attach some sketches and photos to show how I make and fit baffles. I use a fibreglass former, but for a one-off you could shape one from foam and cover with polyester bodyfiller. Alternatively, A 5" wide hoop made from thin plywood would do.


    More diagrams in a minute
     

    Attached Files:

  4. marrio
    Joined: Jun 2006
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    Location: bulgaria

    marrio New Member

    to SEALION Hi, I by chance fell under this forum, and saw that you are a very good in the make of inflatable boats. I am from bulgaria-sofia and invite you to excuse me for my poor english. Started Make a boat from pvc I to do size numbers 4,50-2,20, a diameter of the tube balloon-41-centimeter, and to inflate the two Long It makes the balloon but I now have problems with pattern the curvatures (turn) Her bow of the sea boat. Long Make parts Be 3,30 лю. Pray A help -plans. Thanks. marrio@data.bg
     
  5. joakimhansson
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    joakimhansson Junior Member

  6. Customtech
    Joined: Jul 2006
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    Location: Salem, Or

    Customtech New Member

    Sealion

    In your opinion: I have a 11' inflatable that I wanted to make 4' longer. Would it be worth it? I have done extensive glue and fitting in making Tarps for Flatbed trucks.

    The bottom has come off and will need to be reglued. My thought was to make a 4 1/2' extension and fit it between the front chamber and the rear. Would it need an inside chamber?

    Your thoughts would be greatly appreciated.
     
  7. marrio
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    marrio New Member

    some pictures-under construction:)
     

    Attached Files:

  8. marrio
    Joined: Jun 2006
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    marrio New Member

    1 boat
     

    Attached Files:

  9. wet-foot
    Joined: Sep 2003
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    Location: canada

    wet-foot Senior Member

    Video Class

    SeaLion, you should put together a video on DVD teaching construction techniques. Would be great to work at my own pace to develope the required skills. Set yourself up a PayPal account, I'll be your first customer. Man I thought I was bad when I consrtucted things in the basement, but the living room, wow!!!!!!!! MRS. Mario must be some kind of woman:D :D :D
     
  10. AShley5031
    Joined: Aug 2010
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    Location: Brazil

    AShley5031 Junior Member

    Weird idea for an inflatable boat

    Here is a weird idea.....I live in Brazil and the inflatable boats here are ridiculously expensive. I need a tender for my sailboat. How about taking a really large truck inner tube and inflating it around a fixed base made of some rigid material like fibreglass? Then the tube would take the form of the base. Could this work?

    Ashley
     
  11. Roofdoggie
    Joined: Mar 2011
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    Location: Redmond WA

    Roofdoggie New Member

    Home made inflatable pontoon barge

    I am adding to a 5 year old thread
    Hope it's still alive !

    I am planning to make an inflatable barge for recreation (to haul gear & use as a play platform)
    I am a roofing contractor & frequesntly use PVC roofing membrane & have the tools to heat weld it.
    There are unlimited ways to go w the design- but Im thinking to base it on 2 or 3 big pontoons which will be easy to weld up. I don't know where to get fill valves - or if they could be heat welded to roof grade PVC.

    Anybody out there w some hints ???
    Bob
    Redmond, WA
     
  12. Roofdoggie
    Joined: Mar 2011
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    Roofdoggie New Member

    Roof doggie

    Thats the kind of thing that I would try. A truck innertube is designed to be in the shape of a truck tire. If you fiddle with that shape you compromise the strength & thickness of the rubber. It would probably sort-of work but I don't think it would be reliable. (this is just my opinion) It wouldd be fun to experiment with
     
  13. 8chenuu
    Joined: May 2011
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    8chenuu New Member


    Try these Halkey Roberts valves. They are used for Dinghy Dogs and should be what you need.
     
  14. Roofdoggie
    Joined: Mar 2011
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    Location: Redmond WA

    Roofdoggie New Member

    Thank you !
     

  15. corsarul
    Joined: Feb 2012
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    Location: ploiesti romania

    corsarul New Member

    Hello! ... are in Romania, and will present about how we worked RIB tubes that it's built.
    I found your forum very interesting, and I want to learn a lot from here with you.
    The tubes you see in the pictures (are PVC 900g \ m), unfortunately, I broke because I used a UV often NOT resisted.
    Please indicate to me a quality often leads to do the job! Thank you!
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