Major delamination & foam core options

Discussion in 'Boat Design' started by Will001, May 28, 2019.

  1. fallguy
    Joined: Dec 2016
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    fallguy Senior Member

    My boat is 2" wide on the bottom and has no stringers. Hard chines, bulkheads, knees, beaching keel, vee forward develop stiffness.

    Bulkheads are tabbed to floor in mine.

    How wide is the hull bottom? And what shape?
     
  2. Will001
    Joined: May 2019
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    Location: Lake Macquarie

    Will001 Junior Member

    The general hull shape is a steep V with a flat bottom and a fair bit of rocker (all polycore).
    The bottom sides flare outwards down low maybe 5 to 10cm outside the polycore. This is the foam core which has delaminated.
    The flat section is around 50cm at the widest point on the outside with rounded foam edges. It tapers back to 38cm at the transom. Inside, the bottom of the V is around 35cm near the widest point.
    It's an interesting shape. I guess it gives a lot of bouyancy down low and lift from the flat bottom. 20190530_212509.jpg
     
    Last edited: May 30, 2019
  3. fallguy
    Joined: Dec 2016
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    fallguy Senior Member

    I'm confused. Why would you expect stringers? Isn't it hard chines?

    My guess is the boat had/has insufficient ppi and they added the foam in a desperate attempt to keep her up higher in the water.

    A lot of buoyancy is an oxymoron it seems.
     
  4. Will001
    Joined: May 2019
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    Location: Lake Macquarie

    Will001 Junior Member

    In regards to stringers I'm just checking what is normal. I know 18ft skiffs have a pretty substantial stringer down the middle.

    The boat does sit pretty high in the water. Not sure how it would be without the foam. But it would have very square corners.
    post-21383-094447300 1337345376.jpg
     
  5. JamesG123
    Joined: Mar 2015
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    JamesG123 Senior Member

    They almost look like the anti-torpedo baffles they put on battleships during the inter- World Wars period. lol
     
  6. fallguy
    Joined: Dec 2016
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    fallguy Senior Member

    Yeah, not really going to help adding stringers and my hypothesis is probably correct. The hull shape lacked enough ppi for the rigging and crew. Square corners wouldn't hurt a thing.

    Easy to fix with vacuum.

    But y not just remove the offender and epoxy it all closed if dry?

    If they were unhappy about ppi; you'll know before you bother to paint.
     
  7. Will001
    Joined: May 2019
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    Location: Lake Macquarie

    Will001 Junior Member

    Thanks for all the replies. Looks like you guys were right. Extra floatation added to the original hull. It all came off in a couple hrs.
    I contacted the original owner and he said it was slow to tack so he added the floaties, which were an improvement. Ill give it a run and see how it goes.
    Glad i removed it because it was just holding a lot of water which was causing everything under there to deteriorate.
    20190601_132523.jpg
     

  8. fallguy
    Joined: Dec 2016
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    fallguy Senior Member

    Never heard of dealing with a tack issue by adding sponsons.
     
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