Screwed Up my Rudder! Ideas for fixes?

Discussion in 'Boatbuilding' started by CatBuilder, Sep 1, 2011.

  1. CatBuilder

    CatBuilder Previous Member

    This one is kind of heart breaking - to me anyway.

    My rudder is made up of composite sections grafted onto a steel shaft. The
    sections are airfoil type sections.

    Each section is slightly different from the other and they go in an order from
    largest to smallest.

    I painstakingly make all the parts to perfection. Perfect curves, perfect laser
    alignment on the shaft. Perfect laminate quality, etc...


    I reversed the two top ones, which are so close in size, it is possible to mix
    them up. They are, however, quite different, so the guide to the foil shape
    (these composite sections) is ruined.

    Any ideas on how I can fix this blunder?

    My options seem to be:

    1) Try to somehow graft on some additions to the "too small" composite foil
    section and also grind off part of the "too large" composite section.

    2) Grind days and days worth of work off the rudder stock and start over.

    3) Possibly some other 3rd idea someone comes up with.

    Thanks to anyone who has any ideas on the best way to fix this big mistake.
    Joined: Apr 2010
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    Location: USA

    BATAAN Senior Member

    I doubt it will make ANY measurable difference in the final result and my advice is to proceed as if it never happened.
  3. Quatsino Boater
    Joined: Feb 2011
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    Location: Port alice BC

    Quatsino Boater Junior Member

    I like your option # 2. If you are like me, and by the way you described the carefull steps you took thus far then you are a bit of a perfectionist. No matter what creative or work around solutions you might come up with in your heart you know that something isn't quite right and it will always bug you. Resign to the fact that it will take days to re grind and fix it. You will enjoy the fact that all your hard work is not mearly a cover up but the true intended peice of precise foil rudder that you wanted.

    break out that grinder and dig in :)
  4. rberrey
    Joined: Oct 2010
    Posts: 527
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    Location: AL gulf coast

    rberrey Senior Member

    I,m not sure what you did but I would try to grind and fill first. If I am pictureing it right you have put two frames on your rudder form running the short distance in the wrong order. If so a body file or long board should fair it in ok after you grind it. It wont be the last time you patch up your rudder. Rick
  5. tunnels

    tunnels Previous Member

    You know what has to be done so do it !!:mad:
  6. CatBuilder

    CatBuilder Previous Member

    There is some tough love on here! :D

    All the advice is taken. Before I go and grind things off, here is a picture of how the rudder is made.


    What I have done is reversed "composite ear" number 1 and "composite ear" number 2 (out of 4 total on my rudder). These are the top two in the diagram, but my particular one has only 4 total "composite ears."

    So, these are basically like stations. They are very VERY permanently attached, but the sizes are wrong. Maybe I could add more to the one that is too small and grind some off of the one that is too big? :confused:

    I do have full size print outs of these "composite ears" for each size. Maybe I could use the print outs to figure out exactly how much more foam/glass to add to the short ear and how much to grind off the ear that is too large?

    I'm making another rudder tomorrow (catamaran) and I'll try not to screw it up this time! ha ha ha So there is time for those of you that are mulling it over. It doesn't need to be fixed until this weekend.

    PS: I only have what is pictured in these diagrams. I have not yet infilled with foam or put an outer skin on. Just the "skeleton."

    Attached Files:

  7. rberrey
    Joined: Oct 2010
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    Location: AL gulf coast

    rberrey Senior Member

    The fix for the big one is easy , grind it to the right size. Cut out another large one out of thin glass, slide it over your shaft use it for a pattern to fair the small one to the right size. rick
  8. TeddyDiver
    Joined: Dec 2007
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    Location: Finland/Norway

    TeddyDiver Gollywobbler

    How far did you get with them? Epoxied on the tube and guides? If so grind a bit and just warm the pipes and release the parts, a bit of fix and back they go on the right places..

  9. CatBuilder

    CatBuilder Previous Member

    Finished the bad one to the point in the drawing.

    There is a ton of biaxial on the coves and the ears slide onto the glassed shaft sequentially. They are going nowhere without destroying the part.

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