Abrasion Damaged Hobie Cat

Discussion in 'Multihulls' started by CardboardKing, Jul 5, 2013.

  1. CardboardKing
    Joined: Mar 2013
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    Location: Lancaster, California

    CardboardKing Junior Member

    Hello,

    I recently acquired a 17' Hobie Cat sailboat with trailer. It seems to be in fairly good condition, but during the trip home it slipped off the trailer and sustained quite a bit of abrasion damage to the port hull.

    I've been reading up on fiberglass repair, and it seems pretty simple, but it all seems to assume that you can get to the inside of the damaged area, and that you are working with a flat surface. Is there a way to get to the inside of one of these Hobie Cat hulls? And what would be the best way for me to restore that sharp edge that they have?

    Thank you!
     
  2. tunnels

    tunnels Previous Member

    First how about some pictures with detail and lets see what you are talking about ??
     
  3. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    In an ideal world, you'd like to get at the repair from both sides, but it's not the end all of repair strategies.

    The "Cliff's Notes" version would have you grind back the broken and damaged portions of the laminate, until you reach solid, intact mat. Taper all around the damaged area to at least half the thickness of the hull shell. This taper should be shallow, requiring a number of inches from full thickness to half. Next you'd replace the missing 'glass with more of the same. A cardboard backer fitted inside the hole can help hold the new, wet laminate in relative position, until you've got something to work with. Bulk up the area with more material, until it's very close to the original surface. Lastly, you'll apply filler over the area to blend it in. The sharp edge is done in two stages, grinding and shaping from one side, often using a length of tape as a guide. Then going back and doing the other side, up to the line the tape defined. Lastly, once fair, she's ready for paint or gel coat.
     
  4. tunnels

    tunnels Previous Member

    would still like to see the extent of the damage !! so how about some pictures !!
     
  5. PAR
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    PAR Yacht Designer/Builder

  6. CardboardKing
    Joined: Mar 2013
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    CardboardKing Junior Member

    Yeah, I thought that pictures might be a good idea after I posted the thread. Unlike many Americans, however, I haven't had an Internet-ready photographic device surgically implanted, so that means that I actually have to get my camera out, find some batteries for it, take some pictures, get out my card reader and hook it up, etc., etc. etc....

    PAR's response was pretty much exactly what I was looking for. The idea of using cardboard to create a surface to apply the mat had already occurred to me (I am the Cardboard King, after all), but it helps to hear it from somebody else. And I'm glad to hear that the process of repairing fiberglass from the outside seems to be pretty much the same as doing it from the inside.

    Thanks guys! :)

    P.S. I will post some pictures as soon as I can get them.
     
  7. tunnels

    tunnels Previous Member

    We all have priorities in our lives

    I'll bet if you wanted to post pictures of a pretty lady its wouldn't be such a hassle AND YOU'D even have a smile on your face !!
    WHAT you see and how you describe what you see and ,what we read and how we interpret what you have seen are probably completely different things ,a simple picture posted makes short work of getting help quickly and easily ! we will possibly see things that you don't see or don't think of as being important . :D:p
     
  8. CardboardKing
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    CardboardKing Junior Member

    Okay, so the hole is just about a meter long, and it is 4 cm wide at its widest point.

    Looking at the boat from the side, you can barely even tell it was damaged. And, yes, I did finish digging all the rocks out right after I took the picture.
     

    Attached Files:

  9. tunnels

    tunnels Previous Member

    Theres not much thinking going on here people !!

    wow !! how did you do that ??? obviously quite easy !
    Easiest solution I can think of is take a light skin off the other hull same place and use that as a mould to make a completely new piece to cover the hole and re glass it totally from the outside !! That way you get a exact replica of the hull shape and if you do a real good enough job you or anyone will never be able to tell its been damaged !!
    So get into it !!
    card board ??
    for heavens sake ,what are you thinking ??come on people !!
    If you cock up the shape then you have a massive pooh job for hours and unless you make accurate patterns how will you even get the shape right !
    make a new piece and its exactly the same as it was !!:)


    We did the same thing with a 38 foot yacht in Tahiti had more than half of one side stoved in and pulverized on the reef in a storm so just wax up the other side and after it had gelled released it flipped it inside out and clamped it on the damaged side till it cured then feathered all the edges and cut neatly , disposed of the damaged area and glassed it into place and re attached the new interior bulkheads and furniture again by the time it was finished and sanded and re-gel coated the same colour no one could tell the difference . :D
    Now if you had sent pictures earlier you could have it almost finished by now !! :confused:
     
  10. teamvmg
    Joined: May 2008
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    teamvmg Senior Member

    that's a Hobie 16, not a 17
     
  11. CardboardKing
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    CardboardKing Junior Member

    Well, I'd be more inclined to call it a "Hobie 5," seeing as how it is 5 meters long and, unlike most Americans, I actually prefer to think in those terms.

    Okay, so the question then becomes, what do I use to make the mold? And how much of it will I need? I doubt if it's something I'm going to have lying around the house, so I'll have to buy some.

    Now, keeping it mind these hulls are asymmertrical, will I be able to take a mold from the other hull and just flip it around and transplant it? I feel like I would need a mirror image of the shape of the other hull.
     
  12. nimblemotors
    Joined: Jun 2009
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    nimblemotors Senior Member

    I agree this would be the best approach and strong enough, however, you could glass into the hole some sheet that sticks out a bit so the repair contacts a larger area.
    Or you can just use some solid wood and shape it to match before you attach it with some epoxy.

    If you had a 3/4in plywood hull, it would not need repairs. :)

     
  13. tunnels

    tunnels Previous Member

    debate could rage for weeks ! will i or wont i !! make a choice and do it !!

    You are the person on the spot its completely up to you !! nothing will happen till you make it happen !! get on with it !! its just a repair for heaven sake !!! make a choice and go with it . the difference in shape would be so minimal you will never notice it . Any way if had cared more about how you got it home non of this would have happened !! Right ??:confused:
     
  14. Grey Ghost
    Joined: Aug 2012
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    Grey Ghost Senior Member

    I wondered the same, if there was some clever trick to get a mirror image mold.
     

  15. Petros
    Joined: Oct 2007
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    Petros Senior Member

    cut out templates that fit the good side, and use them flipped over to make the opposite side.

    Looks like it slipped off the trailer and was dragged on the road surface.

    You could glue some foam into the hollow area, use flipped over templates you pulled from the good side to shape it in place (less the fiberglass thickness), and than grind out the good fiberglass as Par suggested to get a good bond from existing good hull to repair fiberglass. Use the templates to do the final fill and fairing.
     
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