Buy or make hatches????

Discussion in 'Boat Yard Basics' started by pgmelton, Jun 9, 2011.

  1. pgmelton

    pgmelton I Love microskiff.com!

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    I started cutting out the foam for my 13ft, 2in skiff and I having a dilemma. This being my first project I am a bit over my head in certain areas, hatches being one of those areas. Buying hatches would run about $270-$300. Hinges, glass, closures and paint would cost about half. The problem is I have never made a hatch.

    Trolling through these threads I have noticed that there needs to be a lip on the under side of the deck to support the hatch. I am not sure how to make that. Also, where do I get and how do I install the black rubber gasket to make the hatch water resistant?

    Thanks in advance for your help.
     
  2. firecat1981

    firecat1981 BBA Counselor

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    $300? how many hatches are you buying? I chose to buy mine this go around as building them last time was a pain and mine weren't water resistant at all. Yes there needs to be a lip if you build them, as well as a drain to channel away the water.
     

  3. Brett

    Brett > PRO STAFF <

    Building a hatch is not difficult, making it water resistant is the real trick.
    Be it constructed from wood or fiberglass, planning is everything.
    Length, width, height, reinforcing, splash lip, gutter, drain and hinge locations
    all have to be planned in advance for it to function properly.
    If the shapes don't match, the weather stripping won't stop the water.
    The deeper the gutter and taller the splash lip the less chance there is of water inflow.
    I've never had a truly water tight hatch on any of my hulls over the years.
    All of the through deck, store bought hatches, leaked sooner or later
    due to dirt in the o-ring, sealant separation between flange and deck,
    or distortion/cracking caused by temperature differentials or load.
    My solution to preventing through deck leaks was simple,
    don't make any holes through the deck, only through the bulkheads.
     
  4. pgmelton

    pgmelton I Love microskiff.com!

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    Hello,


    Firecat, I went to several places in person plus searched online average prices are as follows:

    13 X 24 @ $95.00
    13 X 17 @ $80.00
    11 X 15 @ $60.00 (2 each)

    Grand total $295.00.

    I could probably eliminate the two 11x15 and just leave an open entry (located on the bulkhead that supports the seat facing the bow). If I do eliminate those two I may end up buying them (only 175.00).

    Brett, I PM'ed you.

    Thanks!
     
  5. Gramps

    Gramps Living &amp; Dying in 3/4 Time

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    A few tips I picked up, note that I've never done it myself but it looks good!

    "Here's rough cross-sectional sketch on how my hatches are made. It was a very time consuming process, but they work well and look like professional hatches. All of the surfaces have 6 oz. plain weave (laid on a bias) to mostly protect the exposed foam on the lip.

    The decks are super strong because of the plywood/foam core sandwich needed to create the drain trough.

    The hatch lip has a drip edge***(see detailed explanation below) made of biax fiberglass tape and bonded to the non-radius-ed edge. A fillet is then built up on the inside edge and allowed to cure. Finally the outside hatch edge is rounded over with a router bit. The inside fillet is essentially holding the drip edge in place. The gap is 3/16" and weather stripping fills the space to make it water tight.

    If you bought your hatch hinges already, then you can play around with the dimensions to get nuts holding the hinge to be either inside of the trough or outside so they don't interfere with the lip & weather stripping seal. I missed by about an 1/8" on mine design because I didn't have the hardware at the time I made the trough and lip.



    *** I measured the outside circumference of the hatch edge plus 1 foot for waste. I cut 3 layers of 10 oz. biax tape and laid them out on a piece of plywood that had an area covered with clear packaging tape as a release surface. I laminated the 3 layers of tape together and allowed the epoxy to semi-harden (rubbery, not sticky). I split the laminated tape down the center so I had 2 ribbons - one for each hatch edge. With the ribbons still green and not fully cured, I wrapped them around the hatch edges to allow them to cure to the shape of the hatch circumference. Once fully cured, I trimmed them to fit the hatch edges, epoxied them to the hatch edge, and then used an epoxy/woodflour fillet on the interior side of the hatch to hold them in place. Allow all of this to cure and then finally round over the outside, top edge of the hatch with a router bit. Any slight imperfections were corrected with quick fair. The resulting hatches are pretty much indistinguishable from a production hatch.

    The 3/4" Corecell foam I used was pretty much identical to Divinycell. I had some Corecell from another project, so that's what I used."

    Credit goes to forum member Bob.

    [​IMG]
     
  6. Brett

    Brett > PRO STAFF <

    The driest hatch I had was molded into the deck
    with the gutter feeding direct to the cockpit bulkhead.
    The splash lip curled back away from the hatch opening
    to redirect water away from the weather stripping.
     
  7. Brett

    Brett > PRO STAFF <

    The sides of the hatch channeled water to the bulkhead overlap.
     
  8. Brett

    Brett > PRO STAFF <

    The area of greatest concern is the hinge side
    where the lip of the hatch has to swing clear of the splash lip
    otherwise it'll jam when opening. The other worry
    is keeping the gap between the hatch and deck small
    so objects don't fall in and jam it.
     
  9. Brett

    Brett > PRO STAFF <

    Hatch molds are not difficult to fabricate.
    Some 1x2's, plywood, zip screws make the body of the mold.
    Automotive bondo is used to fillet the corners, then sand smooth.
    Heavy coating of mold release wax all over the interior of the mold
    and you're ready to lay-up a fiberglass hatch.
    After laying up the body of the hatch, the core material is bonded in place.
    The core material, to reinforce the hatch, is beveled back
    so a layer of glass can overlay it and bond/seal it in place.
    After curing, sand smooth, trim off the excess glass and remove from the mold.
    Finish with desired top coat. Not hard, just time consuming.

    If the hatch sticks in the mold, it's easy enough to unscrew the 1x2's.
    once the 1x2's are off, the hatch will peel away from the rest of the mold.

    Yellow is fiberglass, green is the waxed surface of the mold.
     
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