a Novice asking Advice on Adding Gunwhales

Discussion in 'Wooden Boat Building and Restoration' started by jhoward114, Jun 22, 2011.

  1. jhoward114
    Joined: Jun 2011
    Posts: 4
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Wyoming

    jhoward114 New Member

    I've got a beautiful wooden sailboat that I helped a guy build 30 years ago. He designed it based on a Portuguese fishing boat he used in Portugal. I sailed it extensively as a kid, until its one major design flaw became too irritating. It has no gunwhale, (or is strake a better word?) so when the boat is heeled over, the existing gunwhale would be below water level, which was just fine as long as speed was maintained, as the design would deflect water from flowing into the hull. I loved it as it made passengers nervous, but in lake sailing with intermittent winds, it would lead to occasional trouble.

    The boat sat for 30 years in storage of varying and dubious quality, and so now, besides the design flaw, it needs some repairs, especially around the daggerboard column.

    My intentions are to redesign and improved the entire deck/strake construction, strenghen the daggerboard column design, and then refiberglass the exterior hull. For the gunwhale, I'm thinking of using elbows out of 1/2 plywood or solid wood, extending perhaps 6" from the hull inward, tapering back to 3 inches at the stern.

    The key questions I have are:
    • The only ribs in the hull (made of 3/8 redwood strips) are "invisible" fiberglass ribs, faintly visible in the attached photos.
      Can I seat the vertical plane of the rib/hull contact on a wider (perhaps 1 1/4 inch) base, and then screw that base from the outside of the hull?
      How many (spacing) should I have to support a gunwhale I can sit on? Is 1/4 inch plywood thick enough for sitting?
      Would it be better to have a stouter coaming and just support that than having multiple screw intrusions through the hull?

    Re the hull: Generally, except for right around the daggerboard column and along the keel, the fiberglass is in good shape, though I think moisture got inside and there is some mold underneath. Should I still sand it all off and start from scratch? And are there better ways to seal up the daggerboard column?

    My skills with wood related primarily to framing houses and a little bit of cabinet making, and my knowledge of sailing terminology is limited, so I'm open to anybody's thoughts on this process!

    Thanks:
    Jim


    https://picasaweb.google.com/113792...hkey=Gv1sRgCPjK7uCJkr7MSg#5619931417456051138

    https://picasaweb.google.com/lh/photo/PKW28IAGbZXonEoSprKCnFMA3Ir8ZMC2AZxXpXdbKQA?feat=directlink

    https://picasaweb.google.com/lh/photo/FrE-S60CM3ggAcDvSuLJkFMA3Ir8ZMC2AZxXpXdbKQA?feat=directlink



    https://picasaweb.google.com/lh/photo/Xea-MaNtEzIawZwxD2UJU1MA3Ir8ZMC2AZxXpXdbKQA?feat=directlink
     
  2. jhoward114
    Joined: Jun 2011
    Posts: 4
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Wyoming

    jhoward114 New Member

  3. jhoward114
    Joined: Jun 2011
    Posts: 4
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Wyoming

    jhoward114 New Member

    Pictures of Wyoming boat, third attempt

    Wyoming Sailboat photos attached. Looking for expert advice.:)
     

    Attached Files:

  4. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 473, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    That boat looks to be strip planked and internal frames shouldn't be necessary. The top of the daggerboard case appears to have been previously supported by an athwartship thwart (seat), which has been removed. This type of support is perfectly acceptable and the common way of handling the issue in a stiff, but light weight fashion.

    I'm not sure what you're attempting to seal, but I'll assume you mean the daggerboard case to hull shell interface is where your concerns are. Having screws from the outside of the hull, will just introduce dozens of new potential leak points and I wouldn't recommend this method. The photo of her with the thwart, foredeck and inwale in place, show a well thought out arrangement and no additional support would be necessary in my view.

    This said you should approach each issue with the same technique, which is epoxy and fabric reinforcements. An example is the breached sheathing along the keel and daggerboard case exit, under the boat. This should be ground back until you get to well attached sheathing, then new fabric, bonded in place to replace what you've had to grind away. On the inside of the boat, where the case meets the hull shell you should additionally reinforce the case to shell contact areas with a few layers of biax, set in epoxy, over a healthy structural fillet.

    The inwale and sheer clamp arrangement is fine as designed, but possably needs to be replaced. Build it as it was, but glue each piece with thickened epoxy and remove any temporary fasteners that might be needed during assembly, after the epoxy cures. Naturally you'll fill these holes afterward. The deck is the same deal, make it as it was, but bond every thing down with epoxy, using temporary fasteners if necessary, then fill the holes left after they're removed.

    If your desire is to make wider side decks then you'll need some "hanging knees" filleted to the hull shell to support a person sitting on the rail. Space the knees at every other inwale spacer, or every third spacer, depending on how big a knee you use. The simple way to do this is to fillet some 1/4" plywood to the hull shell with a 1x2 glued to the top edge, which will receive the 1/4" decking (also glued down). If you do this you can move the inwale location to the inboard end of these hanging knees and ignore the spacers all together. Yes, the 1/4" ply (if 5 ply, marine grade) will be strong enough, assuming it's well epoxied to the 1x2's on the knees and the new inwale (which actually becomes a deck opening carlin now). Additionally a small coming will help keep the cockpit dry, though don't make it very tall (3/4" to 1.25") along the side of the boat (attached to the deck carlin), because it will dig into the back of your legs when you sit on the side decks, if very tall.

    Personally, I wouldn't go to the trouble of installing side decks on such a small boat. If you do, 6" wide side decks will be more then enough for the average butt, though these will substantially cut into the interior space available when seated normally.

    Log onto westsystem.com and systemthree.com and download their user's guides as research to epoxy use and the various techniques and products available. This will get you started.
     
  5. jhoward114
    Joined: Jun 2011
    Posts: 4
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Wyoming

    jhoward114 New Member

    PAR, thanks so much for your kind response. I understand the concept of the 1/4 plywood knees, with the 1X2 glued to the top edge. What is the ideal process to attach this knee to the hull edge? Do I understand you that I should avoid screws anywhere I can? Can I simply glue it to the hull, and if so should I first get down through the fiberglass to raw wood?

    Learning some definitions here, but is the deck carlin a fore-aft bearing beam?

    Maybe 4 inches of side deck would be a good compromise. Six inches will certainly reduce inboard space, but my experience with the boat says I need something.

    I'll attach more detailed photo's of the daggerboard case condition when I get home.
     

  6. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 473, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    The knees would be attached with a fillet on each side, gluing it to the hull shell. If the 'glass is well attached, you can glue directly to it. It's also important to figure out what the resin is on the 'glass work. After 30 years, it may well be polyester, which will prove a contentious trouble source. It might be more advantageous to remove the polyester bonded 'glass and do it again with epoxy.
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.