Transom repair with honeycomb

Discussion in 'Fiberglass and Composite Boat Building' started by Canracer, Dec 11, 2012.

  1. Canracer
    Joined: Aug 2009
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    Likes: 9, Points: 18, Legacy Rep: 47
    Location: Florida

    Canracer Senior Member

    This is the 15 foot sailboat I am restoring. The aft sections are a little soft and I would love to replace the transom at the same time.

    Here is a link to the restoration. http://plasticclassicforum.com/forum/viewtopic.php?f=37&t=4744&start=150

    I have not worked with cored panels, but would like to get into it.

    Is a transom like this OK to replace with a cored panel?

    [​IMG]
     
  2. alan white
    Joined: Mar 2007
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    Location: maine

    alan white Senior Member

    I imagine that a novice would be challenged to use a lightweight core that depends upon skin strength to do its job. It's a much better idea to use the most popular and practical of cores---- namely one to several layers of plywood as no doubt the boat originally has.
    Nowadays this repair is so common that there is no end of discussion here on the forum in the archives.
    The builder of your boat probably did not laminate and seal the transom with epoxy but it's likely that you wouldn't be up against a repair now if they had. now you can improve on the original construction by a ply/epoxy job.
     
  3. gonzo
    Joined: Aug 2002
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    Location: Milwaukee, WI

    gonzo Senior Member

    If you are using this project as a learning experience, then it makes sense. Otherwise it is a big expense and a lot of extra labor, compared to plywood, without any benefits.
     
  4. Canracer
    Joined: Aug 2009
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    Location: Florida

    Canracer Senior Member

    I understand that a 4 by 8 panel can be expensive (800 bucks maybe.) Also, I guess that actual honeycomb has not been popular for many years.

    The planing sections of the hull need stiffening, so I imagined that the transom and the stringers could be made from the same material. But the transom has hardware and stringers do not.

    Gonzo: The benefit over plywood would be a few pounds (in theory,) and the experience.

    That being said. Where do I start cutting? :)
     
  5. SamSam
    Joined: Feb 2005
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    Location: Coastal Georgia

    SamSam Senior Member

    Stringers from honeycomb? How would you go about that?
     
  6. Canracer
    Joined: Aug 2009
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    Location: Florida

    Canracer Senior Member

    Cut strips, and glass them down.
     
  7. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Honeycomb stringers would have to be stacked, other wise the cell orientation would be wrong (90 degrees off). It wouldn't make a lot of sense to use honeycomb cores in stringers, when foam is available and much easier to work with.

    As to your transom, plywood is the obvious choice for several reasons, though honeycomb could work, but as mentioned, wouldn't be the most novice friendly material to work with.

    The only time you can truly justify these exotic core materials, is when you have a significant weight savings, that can translate into performance. If foam stringers and honeycomb transom are combined with a cored hull and deck, you might save enough weight to improve her performance envelope, justifying the cost and effort of the materials and methods. If not, then you'd be best advised to use conventional materials and methods.
     
  8. Canracer
    Joined: Aug 2009
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    Location: Florida

    Canracer Senior Member

    The deck and the stringers in this boat are foam. Only problem is that they were constructed resin starved. Maybe they thought that was the right way to go.

    I also have to put in bulkheads. They are positioned under the chain plates, and tie in the centerboard trunk.

    The panels add up, and I am concerned about weight.

    This image was shared with me by another C15 owner.
    [​IMG]
     

  9. Canracer
    Joined: Aug 2009
    Posts: 621
    Likes: 9, Points: 18, Legacy Rep: 47
    Location: Florida

    Canracer Senior Member

    Maybe the major surgery will wait till after Christmas. I found no softness in any of the fastener holes. And, it's starting to look to good.

    [​IMG]
     
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