On Wed, 08 Sep 2004 08:17:40 -0400, Jonathan wrote:
Because of a miscommunication with the yard, my Alberg 35 was relaunched
after a haulout for bottom painting without replacing the zinc. I had
taken the old one off (not much left).
Years ago I had a friend drop a fish shaped zinc overboard every time he
came back to his slip. It was supported on a line for the weight, and a
wire from the zinc to....actually I don't remember what it was to, but I
think it was the green wire grounding system on the boat.
If I adopt a similar plan, attaching a wire to the zinc that did not get
mounted and attaching the other end to engine block or shaft, will this
suffice sufficiently until my next haul out? which will not be until
2006 probably....
I believe that the effectiveness of a zinc diminishes somewhat as distance
from the protected metal increases. So you probably want to hang the zinc
pretty close to the prop. I'd use galvanized steel wire to suspend the
zinc. Above the water line, you can switch to copper wire, but make sure
you have a good connection at the junction. Don't let the junction get
wet, and inspect it periodically. Either way, inside the boat, connect the
wire directly to your prop shaft if you can, or some part of the
transmission which is electrically connected to the prop shaft if you
can't. Again, make sure you have a good connection, and try to keep it
dry.
Of course, if your prop is a different metal than your shaft, this may not
be a great idea, either, because it will guarantee that you have current
flowing through the prop/shaft junction. Even so, I think the zinc will
protect the prop. And really, it's no different than mounting the zinc
directly on the prop shaft anyway.
I am concerned as the boat had been in since August 2002, and the zinc
on it was almost completely gone. The boat spends May thru October on a
mooring then November through the end of April at the dock for the
winter.
Thanks,
Jonathan
As others have suggested, your best bet is definitely to get a diver to
install the zinc. I have installed shaft zincs under water before,
although I did it in nice clean, warm, clear water. ;-)
As a side note, theoretically, you can pretty much neutralize your slip by
running a heavy gauge wire around the sides of it, and running a short
pigtail into the water at all four corners. The pigtail should be
galvanized steel wire connected to a reasonable sized zinc at the end. The
pigtail should be long enough that it either almost touches bottom, or is
much deeper than the draft of your boat. This will short circuit any
electric field which might otherwise try to exist in the water near your
slip. You can tell which way the fields go, if they are DC fields, by
seeing which zincs wear out faster.
Note that I've never tried this, but I would like to. If I ever have a
boat again I probably will, just for kicks. I'll still put a zinc on the
prop shaft, though.
--Mac
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