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Thread: Zinc Grounding

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  1. #1
    Chris Warfel Guest

    Zinc Grounding

    Can you tell me if there is a grounding zinc anode on the Ariel. I can't find one in the electrical one line. Thanks for any help.

  2. #2
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    None to my knowledge.

  3. #3
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    Sep 2001
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    Rockville MD./boat kept at Annapolis MD.
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    Zinc

    Every thing on Sirocco is grounded to the engine and the shaft has a zinc on it.I have to replace it every year.I dont know how the outboard models are grounded.
    Last edited by S.Airing; 05-13-2002 at 06:49 PM.

  4. #4
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    Your question, as I understand it is actually two questions. The first question is whether there is a ground plate on the Ariel. If that is the question, then yes, the company issue ground is the water intake on the starboard side and it appears to be bronze. You will find a wire screwed to it.

    If you are asking is there is a sacrificial zink anode for corrosion/electrolosis control, the answer is no. The sacrificial zinc plate on my boat is on the motor. The motor is connected to the boat ground because the motor has a generator. But for the generator and its connection to the battery, there would be no direct electrical connection between the hull ground and the sacrificial zinc plate.

    As for the concept of a sacrificial plate, what happened is the bronze filter plate over the water inlet was eaten away over time and had to be replaced. Now, I have installed a 6"X18" copper plate to the bottom of the boat which is the hull ground to protect against lightning strikes but should not be sacrificial (I hope).

  5. #5
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    speaking of zincs, for you outboard ariel/commanders :
    who has zincs? where do you put them without a prop shaft?
    do you just have one on the O/B and leave it in the drink?
    who has an O/B and has shorepower?
    much grass,
    -km
    aka, "sell out"
    S/V Beyond the Sea
    C&C 35 mkIII

  6. #6
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    I have a zinc attached to the rudder shoe and I attach a cut jumper cable to the tiller head fitting with a zinc on the other end and drop it into the water. The ob is kept below when not motoring, but the Mercury does come with a zinc fitting.

    The rudder shoe zinc lasts about four years. Ditto for the one attached to the tiller head fitting. I have shore power.

  7. #7
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    So does the Yamaha 4/8.
    Has a rectangular zinc french fitted under the cavitation plate.

  8. #8
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    rudder zinc

    so how are the zincs on the rudder shoe or the one you temporarily attach to the tiller head electrically connected to the negative of the battery (12V system) or the grounding wire of the AC? are they connected?

    and is the zinc on the rudder shoe or the ruddershoe electrically connected to the upper rudder shaft and the tiller head and temporary zinc?

    side bar: the rudder shoe, is there fiberglass between the rudder shoe and the inside of the boat, or does the rudder shoe form the pressure hull/watertight barrier?

    how is it attached (i only ask if it isn't in the manual, which i will check after this...)

    much grass to all.....
    -km
    aka, "sell out"
    S/V Beyond the Sea
    C&C 35 mkIII

  9. #9
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    The zinc on the rudder shoe is there to protect it and the lower rudder shaft. Has nothing to do with the boat's electrical system. The zinc on the cable attached below the tillerhead fitting is to protect the upper rudder shaft.

    As far as I can tell, the shoe is isolated by the fiberglass. It is bolted to the hull, but Ebb can give you a better idea since he has removed and replaced the one on #388

  10. #10
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    Bill:

    I sure am no expert in electrolysis, and don't have as much of a problem here that you salt water sailors do. But I don't know why you would want a sacrificial plate on the upper and lower ends of the rudder. Not being connected to anything/electrically isolated from everything, would there would be any voltage differential on the shoe that would create electrolysis?

    In fact, having dissimilar metals (the lower rudder shaft and the zinc plate) are you not creating electrolysis where there was none to start with? I understand that the shafts are a mixture of metals, but still question whether there is an electrolysis issue.

    The zinc plate for the upper rudder shaft might create the same problem?
    Last edited by Theis; 04-06-2003 at 06:58 AM.

  11. #11
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    Peter,

    The rudder shoes and upper rudder shafts of us salt water sailors have experienced failure from electrolysis, probably due to stray electrical current in marinas. Since the rudder shaft is in two sections, a zinc on both ends is required.

  12. #12
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    As I said, I am not a seasoned salt on the electrolysis issue. Assuming the sacrificial plates on the rudder have helped (has this been shown to be so?), then perhaps the sacrificial plates prevent leaching of one of the metals in the bronze/monel shafts.

    The issue is that, without an electical connection, i.e. the shafts being isolated, how can there be currents, even at the dock? Perhaps this is just showing my ignorance of the electrolysis issue. Something to work on next year.

    With other items, there is a "loop" that can conduct the electricity/corrosion (like the outboard motor).

  13. #13
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    This stuff is reallly out of my area, but check out discussions elsewhere about "hot" marinas. Your "loop" is with the dock's source of electricity.

  14. #14
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    Bill:

    I can share with you the perspective that this issue is of my area. At least we are analyzing this thing from a common standpoint. This commonality should be the basis for an enlightening and energetic dialog. Ignorance is so neat because you don't have to concern yourself with reality.

  15. #15
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    Theis,

    About four years ago I replaced a rudder on a Cal 25 three boats down from my existing slip. The stainless steel rudder shaft was completely eaten through near the water line right where the shaft passed through the fiberglass hull. The rudder was fiberglass, and the tiller was wood. The shaft and tiller head fitting were metal, but they were completely isolated from any metal on the rest of the boat. We discovered the problem when we lost control of the boat at sea on a light wind day. We discoverd that the rudder had failed when we notice the rudder floating off the lee side with a sea gull standing on it.

    That ain't a harbor. It's a giant battery.
    Scott

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