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Thread: Norm was right

  1. #1
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    Default Norm was right


  2. #2
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    Default Re: Norm was right

    That looks a mess.
    Tom

  3. #3
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    Default Re: Norm was right

    We didn't put anti-foul on the prop. It really was not supposed to be sitting this long. The barnacles keep the AutoProp blades from finding the correct angle. In consequence, I could not get more than about 800 rpm.

    As Norm predicted, the nut zinc on the end of the prop shaft is gone. A bit surprisingly, the zinc high up on the strut is gone. The shaft zinc is as new.

    We're putting on the leeboards and raising the waterline for this haul.

  4. #4
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    Default Re: Norm was right

    Gonna paint the shaft, too?
    Hope for the best, but plan for the worst.

  5. #5
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    seattle
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    Default Re: Norm was right

    Barnacles on a prop is just a sign the boat isn't used enough.

  6. #6
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    Default Re: Norm was right

    Not used hardly at all. But now we'll get the leeboards on and in a week or so the spars.

    The waterline was probably right - without the masts and 400' of 3/8 BBB in the forepeak she sat down at the stern. And we've reason to think that the waterline was right where she actually floats. Two things about that: The waterline was placed on the plane LFH drew but 2" higher. So, as built she sits down a bit. This may be the extent to which the wanna on the bottom planking plus the larger (over double) water and fuel tankage put her down. I see no problem there. But with a "correct" waterline one always has growth just above the waterline. So in this haul we're going to raise it 3" amidships and some flare at the ends.

  7. #7
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    Default Re: Norm was right

    I'd go back over the sums that sized those zincs, they should last longer than that. May be they are bonded to stuff not included in the calculations or the one on the shaft is not bonded well enough. Now is the time to review that system.
    It really is quite difficult to build an ugly wooden boat.

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  8. #8
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    Default Re: Norm was right

    The shaft nut zinc on these often goes but it appears that there is no damage resulting from just leaving it out. I'm undecided on that as I don't quite see how that happens. The strut zinc is a surprise.

  9. #9
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    Nov 2004
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    Default Re: Norm was right

    Quote Originally Posted by Ian McColgin View Post
    The shaft nut zinc on these often goes but it appears that there is no damage resulting from just leaving it out. I'm undecided on that as I don't quite see how that happens. The strut zinc is a surprise.
    Hate to say I told ya so, Ian, but...

    Well, not to worry.. the prop will clean up just fine.... and as I predicted, you can save $50 each year on buying those useless zincs that cover the securing nut.... they NEVER last. Did you have two conventional zincs on the shaft? I always use two... in a typical year, for my boat, each zinc is about half eaten, after a season... but two provides a bit more security, in case the part of the zinc that holds the screws could erode, and a zinc could fall off.

    Trust me, if you use the spray can prop anti-fouling, the prop will come out of the water VERY clean, next year.... the stuff works amazing well, better than anything I have previously tried.

    ETA: I believe that the special nut zinc erodes very quickly because it's a different alloy, than the ones made for mounting on the shaft.... less noble, or more noble (I forget which). I think Brunton's intention was that the nut zinc would be the only zinc.... but I never had that much faith. Leaving the special zinc off has no effect, based on my 20 years of experience with this kind of prop.
    "Fact is that which enough people believe. Truth is determined by how fervently they believe it."
    --- Charles Pierce







  10. #10
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    Default Re: Norm was right

    I think Norm is additionally right about the nobility of the zinc alloys.
    A boatless inlander, searching for the meaning of life-aground.

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