thompson 240 structural repair

Discussion in 'Boatbuilding' started by gitchedrewme, May 5, 2011.

  1. gitchedrewme
    Joined: May 2011
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    Location: Marquette Michigan

    gitchedrewme Junior Member

    I am repairing my Thompson, stringers, transom, deck, fuel tank. I have many questions. I am replacing the fuel tank, among other items. The space for the tank would allow for a larger tank, in height, than the original. Also the tank I took out is shaped like a belly tank with a flat bottom and angles to the sides, questions;
    is this the shape tank that Thompson installed?
    allowing for fittings, can I put in a taller tank?
    is it OK to install a flat bottom tank?
    6" forward of the bulkhead that is in front of the engine bay there is another bulkhead, the fuel tank was attached to it. Is this original construction? I would like to eliminate this bulkhead to permit a longer tank, but only if I can verify that the factory engineers designed it this way. The two bulkheads so close seems redundant. Thanks for any comments and advice.
     
  2. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    It would be helpful to list the year and model Thomson, plus post some photos, so we know what you're looking at.

    Most factories put in what ever stock shaped tank they can get to fit in the space they have available.

    Without a year and some photos, we'd be guessing at the rest of your questions, but trust me, manufactures don't install things (bulkheads for example) when they don't need to, so consider it structural, possably to absorb bottom loading.

    Welcome to the forum.
     
  3. gitchedrewme
    Joined: May 2011
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    Location: Marquette Michigan

    gitchedrewme Junior Member

    I don't want to change anything unless I am absolutely certain, after my experience as an aircraft mechanic, civillian and Marine Corps, I know the value of being certain. Thanks for your reply, I will have some pics as soon as I can figure out how to load them.
     
  4. gitchedrewme
    Joined: May 2011
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    Location: Marquette Michigan

    gitchedrewme Junior Member

    Here are some pics, the boat is a 1989 Thompson Fisherman 240, 24' long.
     

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  5. gonzo
    Joined: Aug 2002
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    Location: Milwaukee, WI

    gonzo Senior Member

    A flat bottom tank will have less capacity. Also, the fuel will slosh around more which will force you to have a larger unuseable reserve. Even if you make it longer, you'll end up with less capacity. Why don't you like a tank with a slanted bottom?
     
  6. gitchedrewme
    Joined: May 2011
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    Location: Marquette Michigan

    gitchedrewme Junior Member

    Thanks for the info, I see how the slanted bottom will keep fuel at the pickup. The area for the tank is flat. Is the slanted shape to allow the tank to conform to the hull? There is more room in height, allowing for fittings, for a taller tank, 17 more gallons.
     
  7. gitchedrewme
    Joined: May 2011
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    Location: Marquette Michigan

    gitchedrewme Junior Member

    Does anyone recommend any fuel tank fabricators? I have found a few online, Thanks
     

  8. gitchedrewme
    Joined: May 2011
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    Location: Marquette Michigan

    gitchedrewme Junior Member

    Another question, the old filler hose had a low spot, it went from the filler cap to the hull and back up about a foot to the tank. Is this necessary? I would like it to be downhill from the cap to the tank. When the fuel was winterized the treatmentwould go just to the lowest spot in the hose and not to the tank. Thanks.
     
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