Chain locker materials

Discussion in 'Metal Boat Building' started by Steelboat, Feb 15, 2023.

  1. Steelboat
    Joined: Feb 2022
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    Steelboat Junior Member

    Time for a chain box re-design and build. I am considering 5052 5mm (3/16) aluminum plate welded up to make the box. Cheaper materials option would be 12mm (1/2") ply with about 200gm (6oz) epoxy glass and fillets. *Its a steel boat so I need a box.

    I think aluminum faster to build and more durable, but ply quieter underway.

    Any opinions before I start cutting?
     
  2. bajansailor
    Joined: Oct 2007
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    bajansailor Marine Surveyor

    For an aluminium box you could perhaps line it with heavy duty rubber sheeting to make it less noisy?
    I presume that it will have a drain on it as well, so you can wash it out?
     
  3. Steelboat
    Joined: Feb 2022
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    Steelboat Junior Member

    I could but thinking that would lead to nasty poultice corrosion...
     
  4. Rumars
    Joined: Mar 2013
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    Rumars Senior Member

    Any reason why you didn't considered steel? Either normal or stainless?
    If you want to use ply you should use far more glass to coat it, impact and abrasion resistance beeing the problem.
    There are also other options, solid glass and HDPE coming to mind. With fiberglass either a molded piece or by using sheet material (polyester based is cheaper then the epoxy based G10). HDPE can be welded or assembled with screws.
     
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  5. Steelboat
    Joined: Feb 2022
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    Steelboat Junior Member

    I could but thinking that would lead to nasty poultice corrosion...
    Good ideas, thanks. I have to get this big box up the ladder barely fits through the big foredeck hatch and into place, so weight is something to consider. Mild steel is difficult to control rust when in impact situations. Stainless or solid GRP I will look at.

    I had a "welded" water tank fabricated from plastic a few years ago, I think material was HDPE. This might be the best solution for weight and durability over time.
     
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  6. comfisherman
    Joined: Apr 2009
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    comfisherman Senior Member

    Even the best marine aluminum will corrode miserably when placed below deck and set up against chain and the stuff that comes aboard with it. I'd take even a poor grade stainless like a 304 or a glass or poly option over aluminum.
     
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  7. rangebowdrie
    Joined: Nov 2009
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    rangebowdrie Senior Member

    I take it that the space available is probably some weird shape?
    Perhaps another option is a "formed" tank, generally used for water/sewage on boats.
    Ronco plastics can "Rotomold" all kinds of shapes, and you can send them a drawing of what you need if a stock shape will not suffice.
    With such a tank you just cut-out the top to have an open "bin", as it were, the resulting form/shape making a form-fitted plastic liner for your space.
    Download the "Marine Catalog"

    Products – Ronco Plastics (ronco-plastics.com)
     
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  8. Steelboat
    Joined: Feb 2022
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    Location: Seattle

    Steelboat Junior Member

    Great solution thanks. I did not know roto molding was an option for custom shapes. It seems would be much stronger than a "welded" PE tank.
     
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