Multihull Bulkhead Refit Advice

Discussion in 'Multihulls' started by Coastal Ogre, Mar 1, 2021.

  1. fallguy
    Joined: Dec 2016
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    Location: usa

    fallguy Senior Member

    1208 is great for tabbing

    you can wet it all on a table; put it on cardboard and move it to the locations; that is not achievable with no mat tapes; they move too much and must be wetted in place, upside down, etc (pita)

    1208 is, frankly, ideal, for repairs

    no adhesion left in it is sort of a funny way to look at things; a thixotropic bonding material that hardens and is bonded to both sides IS bonded and requires no ability for future bonding
     
  2. Coastal Ogre
    Joined: Jun 2019
    Posts: 41
    Likes: 5, Points: 8
    Location: Florida

    Coastal Ogre Junior Member

    Thank you for the information! The 1208 has been treating me well thus far. Probably why Lagoon told me about it (all these years ago...)

    I'm not sure this 'other' material is/has ever exhibited thixotropic properties. See enclosed picture of both materials. Second frame is after I struck both equally hard with a carpenter's hammer. I wager I will find more of this stuff 'rattling' around the hull during the refit.

    Regards - Ogre
     

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  3. fallguy
    Joined: Dec 2016
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    Location: usa

    fallguy Senior Member

    Some poly bonding putty or some other type that won't heat up when so thick. @ondarvr has seen it all. Gonzo probablu as well. A poly bonding material is about 25% the typ bond strength of epoxy.

    Thixotropic basically means 'thickened and not runny'.
     

  4. Coastal Ogre
    Joined: Jun 2019
    Posts: 41
    Likes: 5, Points: 8
    Location: Florida

    Coastal Ogre Junior Member

    Happy Father's Day to all, from sunny Florida!

    When attaching a plywood bulkhead to a balsa cored hull (and deck) what is the permissible gap between them? I've seen several sketches and drawings on this site, but never any mention of an industry standard, min or max distance to be filled with structural adhesive or epoxy...

    On my girl, I have a fairly uniform 3/4" (19mm) gap between the edge of the ply and the hull structure (see photo). I was planning on mixing up some chopped fiberglass, 406 colloidal silica & epoxy to create a solid connection. However, since this is my mast bulkhead: is 3/4" to much of a gap? Should this be reduced by adding a thin strip of marine ply? And if 3/4" is to large of a distance, what is optimal for the mast bulkhead???

    Of course, I will be reskinning the faces of the bulkheads after this and so the glass will partially be over the thickened epoxy joint further strengthening it.

    Thanks for advise & working knowledge in advance on this question.
     

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