Hatch Cover Material

Discussion in 'Boat Design' started by MJT, Aug 5, 2018.

  1. MJT
    Joined: Jul 2012
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    Location: North Kingstown, RI

    MJT Junior Member

    I'm building new main (companionway) and secondary (deck) hatches, and I'm at the point where I need to choose the tops. Here are three possibilites:

    (1) Tinted polycarbonate sheet is the natural choice, as that would match the original hatches. Strong and transparent, but not non-skid underfoot.

    (2) Marine ply covered with two layers of biaxial glass, painted white and nonskid. Strong, easy, but totally opaque.

    (3) Fiberglass (more than two layers) with no ply substrate. Strong, more glasswork, and translucent.

    I'd like to go with (1), but the cost is a factor. I need two 24"x24" pieces and one 36"x31" piece.

    Is there a serious drawback to not being able to see through the hatches?

    Thanks in advance for any thoughts.
     
  2. Wavewacker
    Joined: Aug 2010
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    Location: Springfield, Mo.

    Wavewacker Senior Member

    What do the hatches go to or where are they located? In the long run I'd go for ply and glass. If you need to see out why does the poly sheet need to be full size, why not smaller in a ply and glass hatch?
     
  3. MJT
    Joined: Jul 2012
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    Location: North Kingstown, RI

    MJT Junior Member

    There are two deck hatches and one sliding companionway hatch. The boat in the image is similar to mine and shows two deck hatches that appear to have a tinted glass/plexi/polycarbonate insert. All have to be strong enough to be stepped on.

    I'm not sure I need to see out, but, on the other hand, it might be convenient to be able to glance up and be able to look skyward.


    [​IMG]
     
  4. JamesG123
    Joined: Mar 2015
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    Location: Columbus, GA

    JamesG123 Senior Member

    Its more than just convenient to be able to check the sails when below and foreward.

    I like tinted carbonate hatches because you can see thru them and they can be simple to fabricate if you're doing a slick modern "frameless" install. Opaque is classical, translucent is like the middle ground, but it can be hard to not have the naked fiberglass look "cheap". Half framed like in the above pic is a better compromise, but expensive. I guess it all depends on what kind of "look" you are looking for in your boat.
     
    fallguy likes this.
  5. Wavewacker
    Joined: Aug 2010
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    Location: Springfield, Mo.

    Wavewacker Senior Member

    I take it back, a boat like that deserves proper hatches, might do one poly and build a fitting teak inlaid hatch and make it pretty....
     
  6. MJT
    Joined: Jul 2012
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    Location: North Kingstown, RI

    MJT Junior Member

    There's a hatch on the aft deck (under the mizzen boom) that does not need to be transparent. That one will be done in teak for sure. Thanks for the thoughts.
     
  7. Squidly-Diddly
    Joined: Sep 2007
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    Location: SF bay

    Squidly-Diddly Senior Member

    I'm pretty sure you can scratch some traction into poly. Just use 1/16" thicker and go nuts.

    You could even get creative and custom scratch a pattern that provides non-slip but also a pattern of clear view. It would look sorta like those old time wooden grate covers you see on old sailing ships. Probably look cool inside with shafts of light in a pattern, while the rest provides nice defused light.

    I bet you'd be getting requests if other boat owners see it, especially the inside effect.

    Maybe a pattern other than simple grate.

    Not sure what best way to create traction on poly. Maybe 20grit (and how used?), maybe high powered soldering iron, maybe heating up something to press into poly (and how hot to heat to soften but not stick or burn)?

    I'm thinking "take some old gear rings about 1.5" wide and about .75 tooth pitch and foot diameter and heat in oven at 350F for 20 minutes, then with heavy duty oven mitts roll on poly. Don't be afraid to make 2nd pass offset from first if .75" too big. Use beveled gear ring and reverse for cross thatch"
     
  8. fallguy
    Joined: Dec 2016
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    Location: usa

    fallguy Senior Member

    Can you expound on the simple frameless bit?

    I need to build two sliding hatches, but they have to be waterproof, so not understanding how they could be frameless. Would you then see slide hardware or is this without hardware, etc.

    I was going to offer to the OP to use the poly, but in a glass or foam frame and you sort of exploded my vision.

    And this can help me, too.
     

  9. JamesG123
    Joined: Mar 2015
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    Location: Columbus, GA

    JamesG123 Senior Member

    Not simple and not really frameless, just that it is polycarbonate bolted to an underlying track and seal assembly that rides on the hatch frame. Its used on a couple of high end and custom boats, but my google-fu is weak today. I guess vertical hatches/companion way doors can be nothing but poly sheet with the hinges and latches mounted directly to it and the seals in the door frame, the stuff is that strong.
     
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