Joe, is this wishful thinking, or would one be more likely to get a response
with the backing of the marina ? Just curious.

FWIW, I installed a galvanic isolator, and my zincs do seem to last longer.
To my feeble mind -- electrically speaking -- that is one answer to this
problem, right ?

"Joe" wrote in message
oups.com...
On Oct 11, 8:13 am, richard wrote:
On Oct 11, 7:33 am, "Roger Long" wrote:
Snip




give him a bill for the
haulout and zincs

On Oct 11, 7:46 pm, "Garland Gray II" wrote:
Joe, is this wishful thinking, or would one be more likely to get a response
with the backing of the marina ? Just curious.

Sure, I've seen boats so bad the the zincs were boiling.. No marina
want's that kind of problem around. And most people are clueless that
they have a short to ground, or could care less..ignorance is bliss.
Now it may be a different story if it's the marina's stray
voltage...maybe.

FWIW, I installed a galvanic isolator, and my zincs do seem to last longer.
To my feeble mind -- electrically speaking -- that is one answer to this
problem, right ?


Wrong!

First... you want your zincs to waste away, that's what they are for.
You want approx 1% of your metal surface area to be zinced, and you
want 75% of that to waste away about every 4 yrs. Better the zincs
than anything else. If your zincs are always like new.. you are going
to have a serious problem down the road.

Many think galvanic isolators cause many more problems then they
solve. I have a brand spanking new one in a box I'll be happy to sell
you. Haven't had time to put it on e-bay.

Joe

"Joe" wrote in message

oups.com... On Oct 11, 8:13 am, richard wrote:
On Oct 11, 7:33 am, "Roger Long" wrote:
Snip

give him a bill for the



haulout and zincs- Hide quoted text -

- Show quoted text -

On Thu, 11 Oct 2007 01:15:37 -0700, richard
wrote:

Same boat, same marina for 5 years-slightly different slip this year.
Boat stays in water 8 months out of the year (Boston harbor). always
have mechanic change zincs when winterizing (he says he did so this
year). discovered the prop had been destroyed by electrolysis as well
as damage to engine trims. never seen anything like this before
pulled boat our and had mechanic put new zincs on. Cost for haul,
wash, new zincs, labor and put back in water-$500 plus the cost of
replacing the prop. mechanic and I decided not to wait on engine trims
can anyone tell me more about what to do about the electrolysis? does
anyone think that this is something that could be covered by
insurance. have never made a claim on any of my boats over the year so
have no clue
thanks

You could ask?
Sounds like the new slip picked up some current going the wrong way.
Too bad! It only takes a volt more negative than the prop in the
surrounding water to eat your lunch. Your prop anyway.

Brian Whatcott Altus OK

"Roger Long" wrote in message
...
Joe got the the reply first and I heartily endorse the part where he says,
"NO, NO,NO".

I didn't think from your first post that you are on shorepower. If you
are, you should turn your shorepower on and off as well. The problem
could be something that has changed in your boat.

Given you apparent level of knowledge (no slight intended), I'm not sure
you should be hooking anything up to the marina electrical system guided
only by a newgroup, despite Joe's level of knowledge. That's why I
suggested a marine electrician.

Look in your boat for large green wires connecting all the metal parts
that touch salt water. Hook the fish to anything that is connected
directly to something that the green wires tie together. The engine
should be tied into this system so you can also just find a good
connection to the block as Joe suggests.

Since you might be able to get compensation from a defective boat as Joe
suggests, I would get a professional in. Nobody is going to believe you.

--
Roger Long

Another tale of woe involving electrolysis.

Our boat was equipped with an expensive folding prop made of bronze (Volvo).
The prop is made with a rubber shock absorber and is electrically isolated
from the rest of the boat and equipped with 3 small zincs.
The zincs would sometimes last 3 months - sometimes much less. The boat hull
also has a large zinc protecting the bronze thru-hulls. We are hooked up to
shorepower with a galvanic isolater. We had a marine electrician check out
the boat for stray voltage - and he did not find any around our boat.

The boat's previous owner had neglected to replace the 3 prop zinzs and when
we bought the boat some damage had been done to the prop with some pink
showing due to elctrolysis - we had the prop reconditioned and it lasted 4
years before it failed.

However, in spite of our best efforts - the prop eventually failed. Because
of our bad experience we decided to replace the folding bronze prop with a
Volvo aluminum prop.

On Fri, 12 Oct 2007 19:44:01 -0700, "claus"
wrote:

However, in spite of our best efforts - the prop eventually failed. Because
of our bad experience we decided to replace the folding bronze prop with a
Volvo aluminum prop.

So you feel that a aluminum prop will be less subject to corrosion
than bronze?

Casady

"Richard Casady" wrote in message
...
On Fri, 12 Oct 2007 19:44:01 -0700, "claus"
wrote:

However, in spite of our best efforts - the prop eventually failed.
Because
of our bad experience we decided to replace the folding bronze prop with a
Volvo aluminum prop.

So you feel that a aluminum prop will be less subject to corrosion
than bronze?

Casady
Yes - and it is also less costly to replace ($200. vs $2,500). On the other
hand, I will lose some speed under sail but since I don't race I can live
with that :-)

Walking down the dock one day and heard a buzzing sound coming from
one of the electrical boxes. This box had a typical yeller cord going to
a sailboat. But, the loop in the cordwas a foot underwater and covered
with boo coo growth. Used a wooden stick to lift the cord out of the
water and tied it off so it couldn't go back in. Buzzing stopped
immediately.
Gordon

On 2007-10-13 11:15:53 -0400, "claus" said:

"Richard Casady" wrote in message
...
On Fri, 12 Oct 2007 19:44:01 -0700, "claus"
wrote:

However, in spite of our best efforts - the prop eventually failed.
Because of our bad experience we decided to replace the folding bronze
prop with a Volvo aluminum prop.

So you feel that a aluminum prop will be less subject to corrosion than bronze?

Casady
Yes - and it is also less costly to replace ($200. vs $2,500). On the
other hand, I will lose some speed under sail but since I don't race I
can live with that :-)

The aluminum prop will disappear more quickly, sad to say.

We found that a feathering prop doesn't so much give us better speed as
*some* speed in lower wind strengths. We often pass our motoring dock
mates as we all head home, particularly when we're flying the kite.

Though I agree with the others that say that it's probably another
boat's problems at your dock, it's possible that the problem may be on
your boat. A dock mate mixed up two leads as he reinstalled his
alternator and nearly lost the boat thereby. The charging system
worked, but it accidently caused galvanic corrosion. A "hot" lead to
the bilge pump sitting in the water could do the same if the insulation
were compromised.

--
Jere Lull
Tanzer 28 #4 out of Tolchester, MD
Xan's new pages: http://web.mac.com/jerelull/iWeb/Xan/
Our BVI pages: http://homepage.mac.com/jerelull/BVI/

"Jere Lull" wrote in message
news:2007101318225116807-jerelull@maccom...
On 2007-10-13 11:15:53 -0400, "claus" said:

"Richard Casady" wrote in message
...
On Fri, 12 Oct 2007 19:44:01 -0700, "claus"
wrote:

However, in spite of our best efforts - the prop eventually failed.
Because of our bad experience we decided to replace the folding bronze
prop with a Volvo aluminum prop.

So you feel that a aluminum prop will be less subject to corrosion than
bronze?

Casady
Yes - and it is also less costly to replace ($200. vs $2,500). On the
other hand, I will lose some speed under sail but since I don't race I
can live with that :-)

The aluminum prop will disappear more quickly, sad to say.

Well, in that case the Volvo sail drive housing - mado of aluminum - should
have disappeared long ago - however it is like new after some 5 years....

Also, considering that savings by not having a diver replace the 3 small
zincs on the Volvo bronze folding prop (appproximately 4 times a year x
$100.) it is still less costly to replace the aluminum prop say once a year
if needed.