On Sat, 14 Apr 2007 06:49:46 -0400, Peter Hendra
wrote:

Hi,
I know that this must have been covered before but all the searches I
do seem to concentrate on wintering marine diesels in climates with a
harsh, sub-zero winter. I really should know the answer after cruising
for a while but this is only the second time the boat has been left.
We have lived aboard permanently for 14 years now.

I was about to check the water level in my 7 year old diesel engine
when the cap and the metal surrounding it just lifted off in my hand -
no effort required as the whole thing was just sitting there. The
short vertical tube that holds the cap had neatly parted with the base

It is mounted on top of my aluminium heat exchanger and must have
corroded away nicely whilst I was absent for 10 months. Fortunately I
do not have to remove the entire heat exchanger which is also a water
jacket covering the exhaust manifold, just a 4 inch square held on by
4 bolts.

Before I left, I ensured that the water had been topped up and assumed
that the coolant additive I had added 5 months before was still there.

Could someone please advise as to how one should leave an engine
sitting there in a warm climate. I had thought that draining the
engine of coolant water would allow corrosion to set in and that the
coolant itself was a rust inhibitant.

I was asked for advice the other day by another cruiser who is about
to leave his boat here in Trinidad.

Thanks and cheers
Peter Hendra


Peter,

I suspect that you have electrolysis. You mention an aluminum heat
exchanger and I'm sure that there is some iron in the engine block and
you have a mini battery there. Rust inhibiter may help but probably
won't eliminate the problem. I'd suggest adding a couple of zinc
anodes to the system. Sort of one at one end of the system and one at
the other.

If I had your problem I'd repair the damage; add anodes, replace all
seals in the heat exchanger; flush the fresh water side with rain
water or other source of clean, soft water; put it all back together
and wait for seven more years. In'sha Allah it will be good.

I suggest replacing seals and flushing the fresh water side as
electrolysis would be accelerated if you have leaked a bit of sea
water into the fresh water side.

As for advise on leaving an engine in a tropical climate I can only
say that I overhauled my Perkins 4-107 ten years ago. Filled the
cooling system with fresh water, added some "green stuff", supposed to
be good for the water pump, anti rust -- sort of magic bullet kind of
stuff. Other then blowing a coolant hose going into Rebak Marina 4-5
years ago have never even added water to the system. Sailing Singapore
- Malaysia - Thailand and other then the blown hose and resultant
water refill have never had to add water to the engine.

So, I don't think you done wrong. Excepting that you probably forgot
the libation for Neptune, the three colored scarves for the Sea
Goddess, and the firecrackers to frighten the devils away the last
time you set sail.



Bruce in Bangkok
(brucepaigeatgmaildotcom)

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