[RESOURCES] Building a Wooden Hull

Discussion in 'Construction' started by NickMyers, Apr 23, 2012.

  1. Anvil_x

    Anvil_x Well-Known Member

    Joined:
    Nov 4, 2017
    Posts:
    1,438
    Location:
    Park Falls, WI
    Hey. Speaking of flared bows and such.

    I'm over here in flat-deck "My scratch-built boats look like scary lunch ladies" land and have never really laid out in my head how you guys get your bow flares.

    Are you guys Kerfing the underside of your subdecks? if so, how deep are your kerfs? Once you have the right shape and the hull is glued together, you epoxy over the kerfs and just call it good from there, right?

    I'm gonna hang out in non-flared-deck Lunch Lady Land for a while longer, but it'd be really cool to see how you guys do flared wooden hulls.

    Pics and step-by-steps would be an amazing resource for posterity
     
  2. Iunnrais

    Iunnrais Active Member

    Joined:
    Jul 11, 2009
    Posts:
    178
    Location:
    Texas
    Build boards are great for this. Take a couple of 2x4s or other scrap lumber and cut the sheer line into them upside down. Connect them together with a couple of other 2x4s and take a piece of plywood and screw that to the frame. You'll have a build surface now with the sheer built in. Take your subdeck assembly and attach it to the board with some wax paper separating it from the board (nails with large heads work great here, nail alongside the subdeck and let the heads overlap the subdeck and pull it down.) Build the framework upside down. After all the ribs and the keel are epoxied in place, you can remove it from the board and it'll maintain the sheer. No real need for kerfs this way.
     
  3. Kotori87

    Kotori87 Well-Known Member

    Joined:
    Nov 8, 2006
    Posts:
    3,162
    Flared bows are a bit of a trick, you've got several options.
    1) Kerf the subdeck. I've seen people do this with a dremel after the subdeck is cut out, but you've gotta have real steady hands to avoid cutting all the way through. The best method I saw was to trace out the subdeck pattern onto a nice big sheet of wood and draw 1" layout lines over the whole thing. The guy I saw do this used some nice 1/4" thick baltic birch, and he used a very thin blade on a table saw to cut about 2/3 of the way through the subdeck in the sections that needed a kerf. After he made the relief cuts, he cut out the subdeck shape on the bandsaw. Very flexible, still very strong, looked very nice. Unfortunately I don't have pictures.
    2) simplify the shape. Rather than trying to do a nice smoothly rising curve section, draw a straight line from the tip of the bow to the point where the upward curve begins. Then you do two subdeck sections, one for the flat part and one for the rising section. The bow ends up at the right height, your main turrets end up at the right height, and you basically draw a straight line in between. Doesn't look quite as good, but at least you don't have to worry about how to make the deck sit right.
    3) build boards like lunnrais suggested can also work, but if you just force the subdeck into position without relief cuts it will leave a lot of stress in the hull. That requires the rest of the structure to be extremely rigid, usually with very thick keels. That's fine for sailboats with a nice round hull and no need for a water channel for damage control, but the few times I've seen combat builders try it, the hull always ended up warping or breaking. If not immediately, then one or two years down the line. I've had to repair a number of hulls like that, one set of four small hulls that I botched and several larger hulls that other builders screwed up.
     
    Last edited: Aug 28, 2020