88 Ozark Deck Boat Rebuild

Discussion in 'Boatbuilding' started by FishinKnot, Nov 19, 2012.

  1. FishinKnot
    Joined: Nov 2012
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    Location: Middle-Of-Nowhere, OH

    FishinKnot New Member

    Recently acquired this 88 Ozark DB-20 (much the same as phil32 has in his thread. I've already picked up on some very good ideas from reading his thread, and plan on implementing them!

    My issues are about the same, but I'm starting from manufacturer's scratch instead of a rebuild of someone else's work. I will be documenting my progress here, along with asking some VERY newb questions. Thanks in advance for any help!
     

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  2. FishinKnot
    Joined: Nov 2012
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    Location: Middle-Of-Nowhere, OH

    FishinKnot New Member

    This past weekend had good weather, so was able to get started:
    [​IMG]

    Everything that is not a main stringer is a 1x6 or 1x3. Additionally, did not find a single screw in anything - everything was stapled together, including the deck (did make tearing up the deck easier, tho)... Thinking I will replacing this with the setup that PAR and phil32 discussed in his thread...

    Looks like every cross member is like this (which is why I'm replacing them), but don't know why. At first I thought it was due to being banged real hard, and each cross piece is like this, but there's no damage to any of the support pieces or the hull...Possible green wood splitting after years of use? Checked the transom and main stringers for rot, and they all test drilled fine.
    [​IMG]

    Finally, during tear down, was taking a look and am now thinking about possibly moving the console to the center and back so that the "couch" will be the helm seat. This frees up a lot of space, but I am a little concerned about the weight distribution - the console will be moved 2 feet back, and 2 feet towards the center. Anyone have any thoughts as far as weight distribution? Took this picture during tear down to see what it would look like:
    [​IMG]
     
  3. Oscar002
    Joined: Dec 2016
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    Location: SW Missouri

    Oscar002 New Member

    Did you finish this project? I have a similar boat that needs the same repairs. Looking for tips.
     

  4. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    The previous thread (link above) offers a fair bit of information. Spend 5 minutes and read it through, for a better idea what's involved.

    To answer your questions, moving the helm aft a little isn't going to upset the boat, as it was designed to handle folks sitting on the aft seat anyway. The console doesn't weigh enough to be overly concerned about and on the centerline is better balanced, so unless you plan on three 400 pounders in the aft seat, you'll be fine.

    The images aren't clear enough to tell what's going on, but one thing is obvious, the structural framing is too widely spaced to be effective. No gussets, stringer and support bonding directly to the hull shell and likely a lousy fastener schedule of dubious type, all contributed to movement between the hull shell and the wooden elements of the structure. This movement slowly, but surely caused the fasteners to pull out and work loose in their holes, introducing more movement and localized load tasking took place, which just breaks stuff. You see, the idea with this type of structure is to have all the parts, bits and pieces help share and transmit loads, so no one or two pieces, have to do all the work. This permits smaller (read lighter and less costly) structures to be installed, but if the structure develops weak points, because of fastener and bond break down, surrounding structural elements have to accept, the now dramatically increased load transmissions (read crap breaks).

    Those athwart supports look to be on 48" centers, which is way too much. Decrease this to 24". The longitudinal stringers appear to be on 16" centers and this is also a bit wide, assuming they used skinny plywood (3/8") for the decking. You can use 16", but evenly space them across the beam AND use slightly thicker plywood for the decking. If weight is an issue, use a 12" - 14" spacing (again evenly) and the same thickness plywood as previously employed. It's usually lighter to use a slightly more closely spaced support system (stringers and athwart braces) than to use thicker plywood.

    If using Lowe's/Depot plywood for the decking, use two layers of 1/4" underlayment, instead of 3/8". You'll glue and screw this together, staggering the seams, as you go. The reason for this is the quality of this type of plywood (big box stuff) isn't great, so you can increase the veneer count by doubling up the decking, making a stiffer sole (what the plywood actually is).

    Lastly, use screws to hold the decking and structural elements together, not nails or staples. Stainless is the way to go and yeah they do cost a good bit more, but they'll be buried in the boat, where you can't get at them, without tearing things up again. Technically, if you use good epoxy procedures, you don't need the fasteners, but if you're a belt and suspenders guy, toss in some screws or through bolts.
     
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