16' Steel Jon Boat

Discussion in 'Metal Boat Building' started by bholly, May 4, 2015.

  1. bholly
    Joined: May 2015
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    bholly Junior Member

    Well I have 0 boat building knowledge but have welding experience and a welder at home. I'd like to make this out of 1/8 mild steel (if possible). I'm not sure where to begin so I'll let you guys know what I need and maybe y'all can help me out. Is 1/8" fine to use or to heavy? What will increase my weight capacity (wider, taller)? I'd like to at least have a 25hp outboard. I really don't know what I should be finding out so I'll just start with that and y'all can come in. All help is appreciated. Btw aluminum is not an option. Steel is provided for me.
     
  2. gonzo
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    gonzo Senior Member

    It will be a beast, but will float and demolish anything on its path. What is the cargo capacity you are looking for?
     
  3. bholly
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    bholly Junior Member

    Between 600-800 lbs. Including engine. Enough for 3 people gas and equipment. Would it be more wise to use 14-16 gauge?
     
  4. Mr Efficiency
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    Mr Efficiency Senior Member

    Have you ever seen one made from steel ? If not, why do you think that might be ? :D
     
  5. gonzo
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    gonzo Senior Member

    I've seen them on workboats for bridges and seawalls where they take a lot of abuse. Steel is about 2.3 times denser than aluminum, but is also stiffer. I would estimate (roughly) that the steel boat will be somewhat less than twice the weight of an aluminum one. If you use 10 gauge it will need a few frames for reinforcement.
     
  6. WindRaf
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    WindRaf Senior Member



    16 - 18 ft, with gauge 10, the load only of the hull will be, about, 700 lb, + engine + people + fuel + equipment.
     
  7. bholly
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    bholly Junior Member

    So too much weight to float? Like I said, I'm completely inexperienced in boat building. Am I expecting too much out of a steel boat? Would needs to be done to make it work?
     
  8. Mr Efficiency
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    Mr Efficiency Senior Member

    1/8 inch of steel is like an inch of plywood, weight-wise. 3/8 inch of ply would be quite adequate. Thinner steel leaves you little leeway before rust pitting turns into perforations.
     
  9. TANSL
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    TANSL Senior Member

    Whatever the most suitable material for your boat, you should ask the advice is backed by something specific. The "experience" can be very ethereal. Request you examples to "helpers", comparing existing ships, or minimum calculations.
     
    Last edited: May 5, 2015
  10. Mr Efficiency
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    Mr Efficiency Senior Member

    There's another possibility, concrete ! Maybe not.
     
  11. waikikin
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    waikikin Senior Member

    Hi bholly,

    Sounds good, shouln't be much harder than making a lowish/wide/16' rubbish skip.... it will be strong, I'd be using as many folded corners as possible, the swim end will need some careful thought as lots of punt style boats sit bow down.... It will be a beast;) but smart like tractor.
    Some generous buoyancy chambers would be a very good idea- these could form longtitudinal seating also acting as framing/stringers......

    All the best from Jeff
     
  12. Mr Efficiency
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    Mr Efficiency Senior Member

    Certainly tough, there was a flood near me recently and some industrial waste bins were swept miles down the creek. Barely a ding in them, they'd have hit plenty of trees and obstacles before upending.
     
  13. WindRaf
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    WindRaf Senior Member


    No, is not a problem, but must design the boat.
    And for design the boat need first to know what kind of boat you really want, and if you really want to build it.
     
  14. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    Welcome to the forum.

    Steel is certainly a possibility and often used, though usually in a gauge that's reasonable for it's use. 1/8" plate is a bit much as Mr. E has noted, though 16 gauge over some modest longitudinals and a frame or two will do. If it's a simple pleasure boat, you'll want to keep it as light as you can, which is why you don't see a lot of small steel boats. If you have a specific need for a particularly tough boat, steel is an option, but finding plans will be tough. It's possible you could convert an aluminum design to steel, though adjustments would probably need to be made to accommodate the weight differences between the two materials.
     

  15. yofish

    yofish Previous Member

    How good of a welder are you, as in experience? Your machine(s) is (are) what?
     
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