Coronado 15 Repair Help

Discussion in 'Boatbuilding' started by multivariablespace, Aug 1, 2017.

  1. multivariablespace
    Joined: Aug 2017
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    Location: Moses Lake

    multivariablespace Junior Member

    I've got to give them credit, if it had bonded better at the bottom the foam roll under epoxy would have been pretty solid, as it is though the foam didn't bond so the whole thing comes loose. Some cross section pictures below.

    I had some leftover teak oil from another project, fun to dress up the wood trim a bit, also in one of the pictures.
     

    Attached Files:

    Canracer likes this.
  2. Canracer
    Joined: Aug 2009
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    Location: Florida

    Canracer Senior Member

    Oh man...that bulkhead. I think that's spray foam insulation and Bondo. Just a guess.
     
  3. Canracer
    Joined: Aug 2009
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    Canracer Senior Member

    A new bulkhead will be a nice upgrade.
     
  4. 5monkeys
    Joined: Oct 2015
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    Location: Herndon,VA

    5monkeys Senior Member

    Oh My! Look at that foam... I agree a new bulkhead will be a huge upgrade. Keep up the good work.
     
  5. multivariablespace
    Joined: Aug 2017
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    Location: Moses Lake

    multivariablespace Junior Member

    I think I'm about done with the mast support. I ran a cedar board from the centerboard slot up into the bow. On top of that I ran two parallel fir boards from the centerboard slot to the hatch. The mast plate is screwed into the fir boards (that's why they are spaced instead of being together, so they catch the screws). I glued in triangular strips of wood to fillet the corners between the deck and bottom of the boat and the mast support, then used cheap fiberglass resin to fillet the cedar board the rest of the way. Then I put down about three layers of fiberglass to hold the mast support boards in place against the top and bottom of the boat, and against the centerboard slot. Then I put some extra fiberglass over the top of all the wood to keep it from getting wet.

    The main problem I had is the epoxy I think was too thin and it would drain from the fiberglass leaving less than saturated fiberglass on the vertical surfaces and a puddle below. I plan to paint a coat of thickened epoxy over the whole thing, but I think it's too late for proper saturation.

    The other problem I had was the fiberglass not staying where I wanted it and rising up a bit. This would create "bubbles" of air under the glass. I got a syringe and "horse needle" from the vet supply store and have been syringing epoxy to fill the bubble. Not ideal, but it will at least keep water out.

    It's sure ugly, but I think it will work. What do you think, ready to try stepping the mast? IMG_20180916_165930415.jpg IMG_20180916_165939552.jpg IMG_20180916_170017650.jpg IMG_20180916_170023446.jpg IMG_20180916_170034691.jpg IMG_20180916_170041983.jpg IMG_20180916_170235948.jpg IMG_20180916_170237820.jpg IMG_20180916_170239736.jpg



    IMG_20180916_165930415.jpg
     
  6. multivariablespace
    Joined: Aug 2017
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    Location: Moses Lake

    multivariablespace Junior Member

    Any suggestions where to get an inexpensive jib sail? The boat didn't come with one. I was playing with the idea of trying to sew one up myself, but not sure if that would be too much work or not.
     
  7. 5monkeys
    Joined: Oct 2015
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    Location: Herndon,VA

    5monkeys Senior Member

    The insides look strong, that's what matters. I wouldn't be affraid to step the mast. Even if it's not perfect it has to be stronger than what you had.
    If you are interested in making your own.. Sailrite has a Kit, looks like it's $234. I've heard good things about their product but haven't tried it myself.
     
  8. Canracer
    Joined: Aug 2009
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    Location: Florida

    Canracer Senior Member

    It's impossible to do perfect epoxy work when you're hanging upside-down, in partial darkness, and stuffed into a tiny hatch. That cedar board you installed from the trunk to the bow looks pretty good. Check out the bulkhead that 5monkeys installed. Something like this should probably be installed before you put the rig up and head out for a sail.

    If you visit and join the C15 group on Yahoo Groups, there is usually someone there that can sell you a used jib.
     
  9. 5monkeys
    Joined: Oct 2015
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    Location: Herndon,VA

    5monkeys Senior Member

    :oops: oh yeah, a bulkhead, didn't notice that was missing in the photo's. I wouldn't sail without that.
     
  10. Canracer
    Joined: Aug 2009
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    Location: Florida

    Canracer Senior Member

    This is 5monkeys bulkhead install. I think it's birch plywood and epoxy. The cedar board that you installed will stiffen up the hull fore and aft, but there's very little preventing the hull from collapsing in the side to side direction. When the sails are up and full of wind, the base of the mast pushes the top of the compression post to the side and down. And the windward side-stay will be pulling the bottom of the compression post in the opposite direction (to the other side and up.) When the hull was new the wooden structural pieces (that you just replaced) were solid, but eventually they got wet and turned to mush. The constant unchecked side to side flexing is what tore the original bulkheads away from your hull.

    bulkhead glassed.jpg
    The center bulkheads look to be slightly more forward than the side "tank" bulkheads. The center bulkheads should be as close to under the mast as possible. The tank bulkheads were installed under the side-stay mounting hardware (the wooden backing plates are visible.) Many people also install a steel strap with bolts that tie the side-stay directly into the bulkhead. A super strong design.

    I sail with a heavy crew, and often in heavy winds with bigger seas. And so I didn't want to worry about damaging anything when the boat was capsized and someone had to climb out onto the centerboard to flip the hull back upright. I installed extra support where the lateral forces of the centerboard are transferred into the hull. (Ignore the black arrow and text.) With thickened epoxy, I installed plywood plates along the sides of the forward part of the trunk. (It looks like I thickened my epoxy with the red fairing filler (micro balloons) but that's not true. It's thickened with West System 406 colloidal silica. I did mix in a small amount of the fairing filler because I thought it helped to distribute the clumpy silica. That red color goes a long way.)

    cbtrunk2.jpg

    Then the plate was tied into the hull and cockpit.
    frames4.jpg

    And framed in. This might be a little too much. I was going for as much strength as possible.
    cockpit3.jpg

    Maybe don't do it like this; but the idea is to box everything in and tie everything together. No one part should handle all the stresses. It's best if the forces are distributed. (In the upper left and right corners you can see some black epoxy. This is also colloidal silica but with a small amount of graphite added. The idea; that it would help to mix the silica into the epoxy.)
    frames1.jpg
     
  11. Canracer
    Joined: Aug 2009
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    Location: Florida

    Canracer Senior Member

    Here's a video of a guy that climbs out on the centerboard. Remember that these conditions are "flat," and with light wind. Add wind and waves, and much more weight would have been required way out on the end of the board. It imparts a serious twisting force into the centerboard truck.

     
    Last edited: Sep 19, 2018
  12. Canracer
    Joined: Aug 2009
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    Location: Florida

    Canracer Senior Member

    Again: No waves and light winds.
    capsized1.jpg
     
  13. Canracer
    Joined: Aug 2009
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    Location: Florida

    Canracer Senior Member

    This is a quick video I put together on my youtube channel to discuss hull flex.

     
  14. Canracer
    Joined: Aug 2009
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    Location: Florida

    Canracer Senior Member

    Check this one out too. Just some basic ideas about sailboat stuff.

     
    Last edited: Sep 19, 2018

  15. multivariablespace
    Joined: Aug 2017
    Posts: 23
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    Location: Moses Lake

    multivariablespace Junior Member

    Good stuff. That bulkhead is a work of art and those boxes under the seat look solid. I'm thinking I should take it out on a light wind day and just make sure their aren't any leaks in it before sealing in the back with a bulkhead. I haven't gotten it in the water yet and I'd hate to find something that needs work on after putting in a wall. Thanks for the info. I'll take some pictures if I get it out.
     
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