Making yer own fixed portlights

Discussion in 'Fiberglass and Composite Boat Building' started by yorktownie, Jul 11, 2008.

  1. kmorin
    Joined: Apr 2005
    Posts: 185
    Likes: 18, Points: 0, Legacy Rep: 231
    Location: Alaska

    kmorin Senior Member

    Changing the Lower Recess Angle

    yorktownie,

    I use SketchUP (Google) for these simple quicky models as the tool set is less time consuming. I think there is a free version?

    If you want to change the uniform tapered recess design shown so you can increase the pitch of the lower recess wall; I would recommend that you convert the lower two corners to cylinders instead of conic sections. These would be cut from pipe of roughly the same size. This would conserve the concentric reducers needed and pipe is less expensive and the cylinder's lower edge would be parallel to the angle of the lower bar's incline.

    Note: if you follow this geometry the vertical side bar will not have a square end cut, but it will weld the same as the concentric reducer parts.

    If the lower two corners were cylindrical from the inner glass flange to the outer bezel profile the incline of the lower recess well piece would get much more steep. This would drain the water that you've mentioned even with tumblehome in the cabin sides.

    Yes, there are tons of concentric reducers, and the links posted will show more details but until you make a drawing those dimensions don't show up to well.

    I'd look at using the cutouts of the plates to rip into the flat bar? These could be ripped on a bandsaw then Vixen filed to a very straight edge, or belt sanded to clean up the band saw edge resulting in using all the long pieces - at least you'd get the shorter end verticals from the middle of the cutouts? If you start butting bars end to end to make a longer flat bar the labor overcomes the material costs, but some of that material can be ripped to make the recess well sides.

    If you were to tap blocks to weld to the inside of the outer bezel, I'd suggest that you use aluminum thread rod extensions. These hex sided 1" or 2" long tapped bars are already made and used to extend thread rod by joining them together. Bandsaw these into shorter lengths and weld them to the back of the outer bezel.

    I'd cut the entire bezel(s) and glass flange from one piece of plate if possible, but that's just my point of view. Speaking of which, as an old welder that is how I tend to solve most assembly problems; welding.

    if you decide to try this in aluminum I'd try to answer any questions if it will help.

    Cheers,
    kmorin
     

  2. CanQua
    Joined: Jul 2008
    Posts: 15
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Texas, usa

    CanQua Junior Member

    Probably around 0.200" would be what i'd recommend. That should be able to stand up to quite a bit of punishment. Obviously the exact size depends on quite a few variables, so it''s easier to over guess than under.

    e-mail sent your way
     
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