Questions on building raft (river)

Discussion in 'Boatbuilding' started by youngtrout, Nov 5, 2008.

  1. youngtrout
    Joined: Nov 2008
    Posts: 16
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    Location: anchorage

    youngtrout Junior Member

    Hello, I was looking into building a cateraft. The frame seems simple enough but I'm a bit stumped on the tubes. I have done web searches and just can not come up with any guides, there are alot of custom makers so it cant be something extremely hard to get into. NRS sells pvc but its expensive.

    I'm looking for any help or tips!!! In terms of materials, process, anything
    thanks
     
  2. Petros
    Joined: Oct 2007
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    Location: Arlington, WA-USA

    Petros Senior Member

    there are a number of fabrics that work, you use them with the appropriate solvent type adhesive. To experiment go get old polyester reinforced PVC fabric used in banners and signs, using the correct type of solvent glue they will make fine inflatable chambers.

    I have heard you can go to the banner makers and find ones that were made in error or not picked up and you can use them to make a raft or other inflatable boat. YOu will still need to make a filler stem, you can buy these from suppliers, or salvage them off of cheap inflatable boats from a second hand store, You also can make a workable stem with fabric and glue, you just have to use a wood or rubber stopper. If you fold the stem over and secure with a rubber band or clamp it will hold air okay for testing or a simple float. For rough conditions I highly recommend using secureable filler stems.

    I seem to remember seeing instructions somewhere on the internet how to make float bags for use in a sea kayak. But it is not difficult, experiment with scraps to get good tough seams.

    Good luck
     
  3. toxictom
    Joined: Feb 2006
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    Location: Anchorage, Alaska

    toxictom New Member

    I've been wanting to try to build a cataraft for some time out of a couple of brand new oil containment booms that I picked up in an auction a few years ago. I basically have two 25" tubes 24' long made out of 40oz. polyurethane. I've been stumped on how to make the ends like a typical cataraft but think I've finally figured it out.
    I'm in Anchorage too. Help me out and we can share the boat. Send me a private message and we can talk.
     

  4. Marjamada
    Joined: Jul 2009
    Posts: 2
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    Location: Arizona

    Marjamada New Member

    Making pontoons from PVC Pipe

    I design and build catamaran sailboats using PVC pipe for the pontoons. I invented a way to heat-shape the bows into the same wedge-shaped, wave-piercing bows you see on modern cats. When people go to buy PVC pipe for a raft or boat, they often don't specify what kind of pipe they want, so they are offered pipe that is too thick, too heavy and too expensive. All of my cats are made from PIP grade PVC drain or sewer pipe. It is white, very thin and light and cheap. My latest cat, RebelCat 5, is made from a 40-foot stick of 10" PIP pipe, and it goes really fast. There is a flotation chart at my web site that might help you design your boat or raft with the right amount of flotation, and the right length. Why length? There is a rule that might surprise you: As the hull/pontoon length doubles, the ride becomes 16 times gentler. That's right. If you sail on a 10-foot catamaran, your ride is 16 times more bumpy than on a 20-foot cat. The shorter cat is going up and down with every tiny wave of chop, while the longer one is riding on the crests. If you like rodeo, go for short. If you prefer a gentler ride, go for longer. More info at RebelCat.com. -Martin Adams
     
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