Curved Portlights

Discussion in 'Boat Design' started by seanprokopec, Oct 18, 2016.

  1. seanprokopec
    Joined: Nov 2015
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    seanprokopec Junior Member

    Hi, I'm trying to fit a portlight to a curved section of a aluminum hull and was hoping that someone might know of a manufacturer that has a portlight design that can accept a radius instead of a flat surface for mounting.

    Anything would be helpful!

  2. daiquiri
    Joined: May 2004
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    Location: Italy (Garda Lake) and Croatia (Istria)

    daiquiri Engineering and Design

    Hi Sean,
    I am not aware of any producer with curved portlights in their catalogue. It is too boat-specific (there are no standard values for the radius of curvature of hulls) and hence has to be designed from scratch for your specific boat.
    Usually it works the other way round, in order to minimize costs - one choses an off-the-shelf portlight design which he likes and then welds a suitably shaped seat or insert to the hull. This insert is the interface between the flat porthole and curved hull.
    An example:

  3. Rurudyne
    Joined: Mar 2014
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    Rurudyne Senior Member

    Please note: the following is offered because you asked about portlights, not portals.

    If you are willing to use plexiglass you can actually mold your own from good quality sheet stock of proper thickness.

    Also, for the hardware, there many be two options depending on how large the port lights you want.

    First, many lower cost CNC gantry systems (including pretty inexpensive home build systems like OpenBuild's C-Beam, which can be customized) will work well with non-ferrous materials like aluminum or brass and there are inexpensive /free work paths for controlling them that start with modelers like SketchUp then to software to determine tool paths and finally continuing to the gCode driver.

    Second is to use a 3D printer to make a plastic "part" which you can then coat with plaster, melt out the plastic, and you've basically got a lost wax mold for casting with non-ferrous metals. There's even ways to recover and reuse the plastic.
  4. TANSL
    Joined: Sep 2011
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    TANSL Senior Member

    I believe that the existing regulations in many countries require that the framework of portlights is metal (often steel) and the plexiglas is not recommended for the transparent element in many areas of the hull. But I do not know what is regulatory in your country.
    In practice, portlights are so small than they do not need to be bent.

  5. Rurudyne
    Joined: Mar 2014
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    Location: North Texas

    Rurudyne Senior Member

    The last was pretty much my understanding.

    But the OP may "want" something even if not needed.

    As I said, of proper thickness and quality plexiglass. Hardware store bought stuff might work for a low speed cruiser that will never see the ocean; but, who knows where someone may someday take a boat it wasn't designed and built for?

    Also, the sort of CNC machines mentioned can work steel (though some extra structural bracing for the gantry may be needed) ... but the feed rates go down.
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