Wrong way to open a glass rudder?

Discussion in 'Fiberglass and Composite Boat Building' started by Nick10009, Sep 17, 2023.

  1. Nick10009
    Joined: Sep 2023
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    Location: Alameda

    Nick10009 New Member

    Hello, apologies in advance if this is the wrong subforum, or doesn't even belong on this site at all!

    A friend of mine acquired a C&C Landfall 43 and has it on the hard getting ready for cruising. He drilled holes in the rudder and after a week it was still weeping, so he decided to cut it open.

    I incorrectly assumed he was going to cut along the edge of the rudder and split it into two halves. My logic being the rudder was formed from two molded halves(?) with the original glue line being on the edge, and that this would allow him to inspect the post. Instead, he cut a panel from the side skin, which I'm guessing compromises the structure of the rudder? Any comments on whether this is OK or not?

    If not, what's the remedy? I'm thinking he still needs to open it by cutting along the edge and then glass the cutout from the inside, then maybe sheath it from the outside? Any comments would be appreciated!

    IMG_20230917_093605.jpg IMG_20230917_093558.jpg IMG_20230917_093554.jpg
    Last edited: Sep 17, 2023
  2. BlueBell
    Joined: May 2017
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    BlueBell . . . _ _ _ . . . _ _ _

    It doesn't really matter how you cut it, you need a new rudder.

    Welcome to the Forum.

    Which Alameda are you from, USA?
    You might want to show that, this is a World Wid Web we're on.
    comfisherman likes this.
  3. kapnD
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    kapnD Senior Member

    “In for a penny, in for a pound”
    Now that it’s open, revealing the rusting armature, it is known that it’s time to replace the whole rudder, or at least strip everything off the metal in order to sandblast and paint.
    I think drilling holes top and bottom , then applying suction to remove what water would come out would have been wiser, then reseal the outside to buy some time.
  4. Nick10009
    Joined: Sep 2023
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    Nick10009 New Member

    Thanks for the replies. To be clear, I'm just asking to satisfy my own curiosity. When I mentioned my thinking to the owner of the boat he simply replied "Hahaha." I think he plans to fill it with pour foam and glass over the outside. He also seems resistant to the idea of pulling the 40 year old chain plates for inspection. If he were a close friend I'd push him on these things, but in this case I think it's going to be "f*** around and find out."

    I had assumed the rudder skins would be fine, assuming you could remove them without damage. Then it would be removal of the water logged foam, new rudder post with tangs and a bunch of thickened epoxy or epoxy foam to glue everything back together. Sounds like that's not the case...

    Also, to answer Bluebell's question I'm in Alameda, California
    Last edited: Sep 17, 2023
  5. wet feet
    Joined: Nov 2004
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    wet feet Senior Member

    Lots of GRP rudders fill up with water and quite often they have a hole drilled in the bottom so the water can escape when ashore.The holes get filled before launching-rinse and repeat.I haven't seen the metal structure get quite that bad and it raises questions about the material selection or whether the builder's metal storage rack was being correctly filled.

    A complete new rudder will be rather expensive and will take a fair amount of time to create.The owner may not find that as funny as the prospect of going sailing soon.Had he split the moulded surface along the centreline,there might have been a good chance of salvaging the skin of the rudder.
  6. BlueBell
    Joined: May 2017
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    BlueBell . . . _ _ _ . . . _ _ _


    Perhaps it could be rebuilt using the existing parts.
    It depends how bad all the parts are, I can't tell from here.

    As to your question, it wasn't the best Idea for your friend to cut into it the way he did, but it can be repaired, it'll just be heavier.
    It may have worked fine for years the way it was before cutting it open, but, again, really hard to know from here.

    All the best, let us know how it turns out.
    bajansailor likes this.
  7. bajansailor
    Joined: Oct 2007
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    bajansailor Marine Surveyor

    Nick, can you find out if your friend has since scraped away enough foam such that he can inspect the condition of the rudder stock within the rudder, and also the condition of the metal tangs that are welded to the stock?
    I think I can see a tang in the photos of the rudder after it was cut open? If the stock and the tangs (and especially the welds attaching the tangs to the stock) appear to be ok, then it should be viable (for now) to fill it with foam again.
    If the outer skin was cut off carefully in one piece, then it might be possible to glue it back on with epoxy, along with some epoxy and glass over the joint?
    We had a survey in March on a 70's Gulfstar sailing yacht - everybody was worried about the rudder, so one side was cut open in similar fashion to what you did above, and the stock and the tangs were found to be in reasonable condition, so then it was patched up and the boat splashed.
    BlueBell likes this.
  8. fallguy
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    fallguy Senior Member

    You can decore and build flanges; then taper grind and glass it all back to same dimension; minor weight penalty.
  9. Tops
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    Tops Senior Member

    bajansailor likes this.
  10. gonzo
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    gonzo Senior Member

    Unless there is extensive corrosion and/or cracks, there is no problem with the structure. The metal only needs to be cleaned. Poured foam comes in different densities. The higher the better for this application.

  11. Nick10009
    Joined: Sep 2023
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    Nick10009 New Member

    Thanks for the replies. Again, the owner of the boat just seems interested in getting the water out of the rudder and glassing it back together. Beyond that and the pictures I don't know anything else, and I haven't seen it in person. I will share the link to this thread with him and leave it at that.
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