Carolina skiff- j16- new floor and need help with leveling/fairing

Discussion in 'Fiberglass and Composite Boat Building' started by CaptTator, May 18, 2024.

  1. CaptTator
    Joined: May 2024
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    Location: Northeast (upper)

    CaptTator Junior Member

    IMG_4374.jpeg IMG_4402.jpeg IMG_4313.jpeg IMG_4402.jpeg IMG_4313.jpeg Hey guys! I don't post much as I love to read the good information (mostly) that you all put out there!

    here's the situation:

    I cut the floor deck out of my J16 because I suspected water in the foam- and boy am I glad I did. I removed 400 pounds of soaked foam (from the transom to about 3/4 of the way to the bow).

    ripped it all out- cleaned it- and decided to go back in with closed cell pour foam and it worked nicely!

    originally I thought I was going to go in with marine grade ply/coosa but now that I've test fit with a piece of standard ply- I'm not sure that's the move. I'm starting to think just glassing over the foam may make more sense . I also left about 1.5-2in of the old deck around the edges to give myself a flange/reference point to where the floor needs to be (also so the wood could lay on top of it)

    As far as the foam- I used a grinder and a planer to get it as even as I can (still have some high spots but can't seem to get it flat) . Is there a tried and true way to get it exact?

    how would I go about evening out the foam to make a good floor to epoxy/glass over?

    or

    could I go with a thin piece of marine ply and use the 1708 biax to create the stiffness?

    My concern with the wood is that it will not lay flat no matter what I try. So even if I try to PL loctite/epoxy it to the foam itself using cinder blocks as weight- it wont adhere right.


    keep in mind this is my first time ever doing something like this (minus the epoxy/glass) and I'm just doing my best but also want to do a good job. It's a duck boat so it doesn't have to be perfect either!
     
    DogCavalry likes this.
  2. fallguy
    Joined: Dec 2016
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    fallguy Senior Member

    Most pour foam is 2 pound density and not considered structural. So, first thing is to recognize your foam does not support the floor and will also crush under foot loads.

    In your photo, there is no way for us to see if there is any stringer or structural elements where you poured foam. Typically, a stringer or transverse frame or floor is where the plywood is meant to bond to…

    Getting the foam nicer is done by pouring into hole cuts after the sole is applied.

    Leaving even closed cell foam with grinds and cuts is not ideal.

    So, were there stringers?
     
  3. fallguy
    Joined: Dec 2016
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    fallguy Senior Member

    It is a good looking boat. Absent stringers, I’d be inclined to lay 12mm or 1/2” ply over the entire sole and bond it down on rough ground glass, not gelcoat. The bonding would be best done with epoxy with cabosil. I’d probably biscuit the edges over the foam to keep it monocoque or minimize movement on the seams.

    Then, I’d glass the bottom with a single layer of 1708 and tab the sides with two layers of 1708 tapes
     
  4. CaptTator
    Joined: May 2024
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    CaptTator Junior Member


    First time I've ever run into this - but it doesn't have stringers. It has a weird rib system
     

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  5. CaptTator
    Joined: May 2024
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    CaptTator Junior Member


    Also just to make sure I have it understood:
    prep/sand the gel coat where my "flange" is,

    -use cabosil (thickened epoxy) and use that to bond the edges essentially,

    -then- cut some pour holes and see if I can pour foam into it so it fills the voids
     
  6. Blueknarr
    Joined: Aug 2017
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    Location: Colorado

    Blueknarr Senior Member

    You missed the opportunity.
    Either remove the foam and start over
    Or
    Don't worry about it.
    As is a sealed sole will last at least a decade before the foam needs to be replaced.

    Removing foam/laying the sole/refoaming. Will earn an extra year or two.

    There is not enough room between the ground foam and sole for a second pour to spread properly.

    I would:

    Use a straight edge (length ot 2x4) sliding along the flange to identify all high spots.

    Use 3/4 marine ply with three coats of epoxy on bottom and edges.

    Thickened epoxy with screws to the flange.

    Remove screws and fill enlarged holes with epoxy.

    Two coats of epoxy on top of sole ply.
    One layer of 1708 with epoxy.

    Paint and non-skid

    Enjoy for nine years
    Sell it for someone else to redo foam.
     
    fallguy likes this.
  7. CaptTator
    Joined: May 2024
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    CaptTator Junior Member

    that sounds like a solid plan!, thank you for helping me think through this!
    One more question:

    for the thickened epoxy- when adding in cabosil- can I also use that to fill the old scupper holes to make them water tight? Or should I use a different thickener?
     
  8. Blueknarr
    Joined: Aug 2017
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    Blueknarr Senior Member

    Cabo will work fine on the suppers.

    Remember
    The ply will start to rot quickly if the epoxy shell is pierced. All fasteners need to be in overbored and filled holes.
     
    fallguy likes this.
  9. fallguy
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    fallguy Senior Member

    You cannot use thickened resin to fill scupper holes. Blueknarr forgot epoxy cannot fill massive holes is all. Epoxy will crack at about 3/4” x 3/4”. You have to fill the scuppers with something like marine foam, cut to fit. You could actually use pour foam and glass over it with maybe two layers of 1708..
     
  10. fallguy
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    fallguy Senior Member

    The ribs or transverse frames or floors, call them what u like, should have been bonded to the sole.
     
  11. CaptTator
    Joined: May 2024
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    CaptTator Junior Member


    Yeah, big mistake on my part. But- the good news is I learned from it!

    as far as plugging the 1in scupper holes-
    Can I get a dowel (soaked in epoxy of course) then fill it with thickened epoxy till flush , then glass over it?

    Instead of wood I actually have decided to change course to that 1/2in nidacell (I think that's how you spell it?, it's the honeycomb stuff) for weight reduction!
     
  12. CaptTator
    Joined: May 2024
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    CaptTator Junior Member

    Here's a picture of what I'm talking about!
     

    Attached Files:

  13. BMcF
    Joined: Mar 2007
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    BMcF Senior Member

    Perfect timing on this thread....I'm considering the options for gutting my own "waterlogged" 16' Carolina skiff. I cut out a "sump" at the transom, so far and core-drilled a 1" drain hole in to that. Just that intrusion drained slowly for weeks. I've resigned myself to cutting the entire deck out, as you have.

    Our offshore island club has had a small fleet of Carolina skiffs for a long time. Some of the earliest ones had a single-skin bottom that would fail over time and the abuse of being a water truck. When Carolina went to the 6" cored (foam filled) bottom, they really didn't do us any favors.
     
  14. CaptTator
    Joined: May 2024
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    CaptTator Junior Member

    thats crazy! ,

    all in all
    -1 day to remove the deck skin.
    -1 day to remove the foam (get a edging shovel (the real narrow one) and cut it down to about 1/2 in from the width of each rib. Made my job 3x easier.

    -1 day to pour all my foam (2lb) - WORK FAST.

    -1/2day to level foam: buy a cheap planer and a grinder floppy disc - super quick work.

    and now were to where you see!

    I love these boats but I just don't see how they thought this was a good idea!
     
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  15. BMcF
    Joined: Mar 2007
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    BMcF Senior Member

    When my 16' was still young, it got on plane nicely with as many as four persons on board, or two with a weekend load of luggage and supplies. 4oHP Honda. Toward the end, she would barely get on plane with just two people on board..nothing else...and the "self-bailing" cockpit drains were no longer above the static waterline. Time for an intervention...
     
    C. Dog likes this.
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