Various Questions

Discussion in 'Metal Boat Building' started by KI4NCW, Dec 17, 2006.

  1. KI4NCW
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    KI4NCW Junior Member

    Ok Now i have what is probably a stupid question? How do i check the hull for leaks? Fill it up with water?
     
  2. KI4NCW
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    KI4NCW Junior Member

    yes to check for leaks as its built.
     
  3. rayk
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    rayk Senior Member

    [​IMG]
    Voyager 20
    20' (6.1m) 'deep V' cruiser for outboard motors.
    For construction in plywood or as a mould for grp/frp.
    Beam 7'11". Engines 60 to 300hp.

    If you intend to build this boat, you are going to need a little more faith in your abilities.
    The designer, design, construction technique, and materials have been proven over many, many years.

    :!: This boat is a big project and a lot of money.
    Maybe you should consider buying a second hand boat to start with, and getting a bit of experience. Please take a Coastgaurd course before casting off.
    If you really must build something, try a very small dinghy, and launch it in a knee deep pond.
     
  4. KI4NCW
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    KI4NCW Junior Member

    I think u missed my point. I have been a welder for many years and have seen welds that were perfect to the eye that leaked.
     
  5. Poida
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    Poida Senior Member

    KI
    I work for a sheet metal company and I am fairly sure they use something like kerosene sprayed on the joints for testing. As it is lighter than water it penetrates easier and will pick up leaks that water will not as the surface tension of water will prevent it penetrating the hole.

    Also as I understand it does not create a problem when you grind out and reweld, water would create steam so you would have to spend time drying it out before rewelding it, kero would evaporate easier.

    It is not a stupid question because as you said a weld that looks good can leak, however most companies doing that sort of work would rely on the paint job to seal any holes.

    People who say they don't do crap work probably don't test it.
     
  6. SamSam
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    SamSam Senior Member

    Well, I don't think you should rely on paint to seal the leaks. To fill the boat with water could be a disaster. They are designed to be full of air and sit in water, not to be full of water sitting in air. A friend had a small aluminum boat on a trailer and wanted to put some water in it to keep it from blowing away in a hurricane. He stuck the hose in it and forgot, came back to find his boat bent out of shape, the trailer axle and frame bent, springs broke. Just do good work, put the boat in the water before all the interior stuff blocks access, pull the boat and fix any leaks. Sam
     
  7. timgoz
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    timgoz Senior Member

    K,

    The Voyager 20 is not a steel design. My apologies if you already realized that.

    TGoz
     
  8. rayk
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    rayk Senior Member

    Dead right Poida ;)
    If unfamiliar with a new building technique or materials, practise on test pieces, then a small cheap project next.
    Confidence, skill, and experience gained will eliminate the need for a testing regime, when you start building The Big One.
    In a nutshell, 'test' something cheap and small.

    All construction techniques break down into basic steps that follow one after the other, to produce a leak proof join.
    Practise it over and over with scrap material or small projects until it is second nature.
    Then build the boat of your dreams :)
     
  9. KI4NCW
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    KI4NCW Junior Member

    I know the voyager 20 is not a steel design. Hartley is sending me the changes to the plans to build with steel. As far as the welding goes it wont be a problem, I have been a certified welder for years, have welded high pressure pipe and vessels. I just thought testing may have been one of the steps to follow.
     
  10. george allard
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    george allard Junior Member

    I checked the Hartley plans and it seems that you could purchase a used aluminum or glass boat, ready to go, for less then the cost of building the Hartley.
     
  11. KI4NCW
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    KI4NCW Junior Member

    Probably could. What would the challenge and reward be in that?
     
  12. Gilbert
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    Gilbert Senior Member

    Someone can correct me if I am wrong but no one has mentioned this. It is standard practice of the steel boat builders I know to backgouge their plate welds and run another bead. I realize this may not completely eliminate the possibility of a leak but it should come pretty close. I also realize the plate for a 20 foot steel boat will be very light; perhaps so light that backgouging might be troublesome.
     
  13. Poida
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    Poida Senior Member

    And I am probably more wrong in the fact that a 20ft boat is too small for steel construction in that the minimum steel thickness you need for suitable welding is 3mm 1/8" making a 20 foot boat too heavy for it's size.
     
  14. george allard
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    george allard Junior Member

    To turn the boat over, lower one side to the ground. Any 5 ton crane, with a good operator, could hook to the raised side and turn it up. Let it rest on one side and rehook to both sides to level it for the stands. It works for us all the time.
     

  15. KI4NCW
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    KI4NCW Junior Member

    Starting

    Well I finally got my plans for the 20' Voyager. Will begin the Jig tomorrow, I will show pictures as the building progresses. Ribs & Frame are to be 2" X 1/4" flat bar and the hull plated with 3MM steel. I'll keep yall posted.
     
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