Wa'apa fiberglass question

Discussion in 'Multihulls' started by John Bjorklund, Aug 12, 2025.

  1. John Bjorklund
    Joined: Aug 2025
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    Location: Arlington Virginia

    John Bjorklund Junior Member

    Hello all. First time posting here but been following for a while. Really appreciate all the great opinions and information.

    I have been building a Gary Dierking design Wa'apa outrigger sailing canoe off and on for several years. 16' version.

    My question is, I have two layers of chopped glass and epoxy on the bottom of the hull, and up the sides two inches. Is that enough fiberglass, or should I add a layer of 6oz woven cloth as well? The plywood is 3/16 and there are chines in the interior.

    I understand I should have started with cloth, but for whatever reason did not. My concern is adding additional weight to the boat.
     
  2. waterbear
    Joined: Mar 2016
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    waterbear Senior Member

    What type of 3/16 plywood and where did you get it? How many ounces is the mat?
     
  3. John Bjorklund
    Joined: Aug 2025
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    Location: Arlington Virginia

    John Bjorklund Junior Member

    The plywood is marine grade and a friend of mine got it for me from Hatteras Yachts, where he worked. 3 ply I believe.

    I do not know how many ounces the mat was.
     
  4. John Bjorklund
    Joined: Aug 2025
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    Location: Arlington Virginia

    John Bjorklund Junior Member

    The hull is not sheathed in fiberglass, only the bottom. I'm thinking I may need a sheath the entire outside of the hull.?
     
  5. waterbear
    Joined: Mar 2016
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    waterbear Senior Member

    The design is 6mm marine ply with 6oz glass on the bottom, but not the sides. The glass is likely just for abrasion resistance, not strength

    -Cloth is probably 2 yards x (6oz glass + 6 oz epoxy) = 24oz. So a couple extra pounds - not a huge deal. That said, it might be ok without it.

    -You could also add a few transverse solid strips to stiffen it up and compensate for the thinner ply.

    -You don't need to glass the sides.

    -You can weigh a scrap of mat to find the weight of the mat, that way you can figure out how much is already on there.
     
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  6. John Bjorklund
    Joined: Aug 2025
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    Location: Arlington Virginia

    John Bjorklund Junior Member

  7. Kurtz
    Joined: Apr 2023
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    Location: FNQ Australia

    Kurtz Junior Member

    I'm fully sheathing mine with 240gsm basalt, but it will kept on a swing mooring - so it's there for protection mostly.
    I went two layers of 240 woven on the bottom with multiple coats of white tinted epoxy over the top of them (attempt at a gel coat)

    The white tint is just to show damage easier as the underneath basalt layers are black.
     
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  8. BlueBell
    Joined: May 2017
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    Location: Victoria BC Canada

    BlueBell . . . _ _ _ . . . _ _ _

    John,

    Welcome to the Forum.

    You should stay as close as possible to the design, the plan, the one that's proven and meets your SOR, right?
    Then you'll get what you expected and wanted in the first place, a proven design that meets your SOR, right?

    Don't add any more epoxy to the bottom.

    Pictures? We love pictures.
     
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  9. John Bjorklund
    Joined: Aug 2025
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    Location: Arlington Virginia

    John Bjorklund Junior Member

    So I started this build 10 years ago but had to move from NC to northern VA 8 years ago. Left the boat in a basement for 8 years, but just picked it up last weekend to finally finish. Crazy huh. I will be building it on our small back porch off our town house. Just built racks for storage. Will cover with a tarp.
     

    Attached Files:

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  10. Kurtz
    Joined: Apr 2023
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    Location: FNQ Australia

    Kurtz Junior Member

    Nice!
    What sort of rig are you thinking of?
     
  11. John Bjorklund
    Joined: Aug 2025
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    Location: Arlington Virginia

    John Bjorklund Junior Member

    Hi Kurtz. I am thinking a simple lateen rig. Also going to build a rudder since the steering oar can be troublesome I hear.

    What rig are you going to use?
     
  12. Kurtz
    Joined: Apr 2023
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    Location: FNQ Australia

    Kurtz Junior Member


    I'm going to try a Hobie 16 rig and floats. but I reckon the lateen rig is probably what I need.
    It;s either blowing 20 knots or nothing where I'm at. Easier enough to swap between the two I think?

    When you start on the rudder, post some pics and share please.
     
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  13. John Bjorklund
    Joined: Aug 2025
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    Location: Arlington Virginia

    John Bjorklund Junior Member

  14. Kurtz
    Joined: Apr 2023
    Posts: 28
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    Location: FNQ Australia

    Kurtz Junior Member


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