"Roger Long" wrote in message
...
Can anyone out there give me some informed and real world (yeah, I know
this is a newsgroup but, hope springs eternal) insight as to how
vulnerable raw water cooled engines are to damage from freezing?


My Volvo is designed for sea water cooling and each cylinder jacket,
manifold and the OEM "water lift muffler" has a drain cock. Seems like a lot
to remember each fall but these drain every drop of water from the block. To
prevent these cast iron surfaces from rusting over the winter, I have
three-way sea cock that allows me to pump anti freeze into the system. I
don't actually do this, here in PacNW, since the temp never get that cold in
my boat (heater) and I like to have the option to go out for you sail when
the winter weather is nice.

Check the location of your drain cocks on you Yanmar, see if they drain all
the lowest points.

I happen to have a small Volvo MD7A here with a cracked exhaust manifold
because this model didn't have a drain cock and it must have frozen the
standing water. Such a drain cock would have saved this nice little engine.

Now I'm rambling. Sorry.

Steve
s/v Good Intentions

Sorry but 'drying' a cast iron engine will greatly shorten the service
life. What happens is that the cast iron begins to form 'slab rust'
..... huge plateletts of ferric rust that propagates between the natural
'laps' of the casting. Cast iron, due to the way it cools when molded
is similar to an 'onion' ... and the ferric corrosion (usual severe
rust) will rapidly develop between the 'laps' and form ferric rust ,
develop extreme pressure between the natural 'laps' and begin to
destroy the casting. If you keep the engine 'wet' (using such things
as antifreeze with rust inhibiters0 this process is greatly retarded.
Cast iron is a good metal vs. sea water as the high operating
temperature produces 'ferrous' rust ... a blue/black oxide that
actually protects against ferric rust.

The moral of this story is dont 'air-dry' your engine by draining all
the water out ..... put in a mixture of water and antifreeze - and
this will keep the protective 'ferrous' layer intact. Otherwise,
expect to develop pin holes and leaks in short order.

hope this helps.

In article , Steve
wrote:

"Roger Long" wrote in message
...
Can anyone out there give me some informed and real world (yeah, I know
this is a newsgroup but, hope springs eternal) insight as to how
vulnerable raw water cooled engines are to damage from freezing?


My Volvo is designed for sea water cooling and each cylinder jacket,
manifold and the OEM "water lift muffler" has a drain cock. Seems like a lot
to remember each fall but these drain every drop of water from the block. To
prevent these cast iron surfaces from rusting over the winter, I have
three-way sea cock that allows me to pump anti freeze into the system. I
don't actually do this, here in PacNW, since the temp never get that cold in
my boat (heater) and I like to have the option to go out for you sail when
the winter weather is nice.

Check the location of your drain cocks on you Yanmar, see if they drain all
the lowest points.

I happen to have a small Volvo MD7A here with a cracked exhaust manifold
because this model didn't have a drain cock and it must have frozen the
standing water. Such a drain cock would have saved this nice little engine.

Now I'm rambling. Sorry.

Steve
s/v Good Intentions

I agree and don't drain my engine unless I plan to lay it up with
anti-freeze.

As I mentioned in my reply to Richard, I have provisions for pumping
anti-freeze into the cooling jacket, if I were in a colder climate or didn't
keep a heater going in the winter.

Steve
s/v Good Intentions


"Rich Hampel" wrote in message
...
Sorry but 'drying' a cast iron engine will greatly shorten the service
life. What happens is that the cast iron begins to form 'slab rust'
.... huge plateletts of ferric rust that propagates between the natural
'laps' of the casting. Cast iron, due to the way it cools when molded
is similar to an 'onion' ... and the ferric corrosion (usual severe
rust) will rapidly develop between the 'laps' and form ferric rust ,
develop extreme pressure between the natural 'laps' and begin to
destroy the casting. If you keep the engine 'wet' (using such things
as antifreeze with rust inhibiters0 this process is greatly retarded.
Cast iron is a good metal vs. sea water as the high operating
temperature produces 'ferrous' rust ... a blue/black oxide that
actually protects against ferric rust.

The moral of this story is dont 'air-dry' your engine by draining all
the water out ..... put in a mixture of water and antifreeze - and
this will keep the protective 'ferrous' layer intact. Otherwise,
expect to develop pin holes and leaks in short order.

hope this helps.

I used to have a raw water cooled engine, and used to winterize by
pumping antifreeze through it, and closing the cocks. Let the engine
run to temperature so you circulate the antifreeze. Inboards tend to
stay a little warmer since they are closer to the water, which tends to
retain temperature, and protected in some way from the elements. I
would doubt that the first night or two in high 20s will cause it to
crack, but why strain it? I'd plumb a second connection to the
raw-water intake so you can easily and quickly pump some antifreeze
through it, easily enough to do it every time you get back from a trip.
You may also consider a "block heater" type device--I used one in my
car, which did not have an integral one, in -40 degrees. That one was
magnetic, designed for lawn-mower sized equipment, but it worked well
enough: plugged it in, and it attached magnetically to the engine. I
don't know how well it would work against freezing, and I doubt that
you can find one that is appropriate for marine use, so take that for
what you paid for it.

mickey

Simple answer to that is to add valved tee connectionIn to the intake
line and drain cocks teed to a common. Just drain the raw to the
bilge, saving if antifreeze into a bucket. simply, suck the antifreeze
back in when shutting down.


article , Steve
wrote:

I agree and don't drain my engine unless I plan to lay it up with
anti-freeze.

As I mentioned in my reply to Richard, I have provisions for pumping
anti-freeze into the cooling jacket, if I were in a colder climate or didn't
keep a heater going in the winter.

Steve
s/v Good Intentions


"Rich Hampel" wrote in message
...
Sorry but 'drying' a cast iron engine will greatly shorten the service
life. What happens is that the cast iron begins to form 'slab rust'
.... huge plateletts of ferric rust that propagates between the natural
'laps' of the casting. Cast iron, due to the way it cools when molded
is similar to an 'onion' ... and the ferric corrosion (usual severe
rust) will rapidly develop between the 'laps' and form ferric rust ,
develop extreme pressure between the natural 'laps' and begin to
destroy the casting. If you keep the engine 'wet' (using such things
as antifreeze with rust inhibiters0 this process is greatly retarded.
Cast iron is a good metal vs. sea water as the high operating
temperature produces 'ferrous' rust ... a blue/black oxide that
actually protects against ferric rust.

The moral of this story is dont 'air-dry' your engine by draining all
the water out ..... put in a mixture of water and antifreeze - and
this will keep the protective 'ferrous' layer intact. Otherwise,
expect to develop pin holes and leaks in short order.

hope this helps.

Steve,
I'd be curious to see how cold it gets near the engine in a sailboat
sitting in Hood Canal in winter. I doubt the temperature of the salt water
gets below 40 F and if the boat is sitting in it, the boat should stay that
temp. Also seawater freezing temp is about 28.4 F .
I can't see a block freezing and breaking in those conditions,
Now if the boat is on the hard, different story.
Gordon

"Steve" wrote in message
...

"Roger Long" wrote in message
...
Can anyone out there give me some informed and real world (yeah, I know
this is a newsgroup but, hope springs eternal) insight as to how
vulnerable raw water cooled engines are to damage from freezing?


My Volvo is designed for sea water cooling and each cylinder jacket,
manifold and the OEM "water lift muffler" has a drain cock. Seems like a
lot
to remember each fall but these drain every drop of water from the block.
To
prevent these cast iron surfaces from rusting over the winter, I have
three-way sea cock that allows me to pump anti freeze into the system. I
don't actually do this, here in PacNW, since the temp never get that cold
in
my boat (heater) and I like to have the option to go out for you sail when
the winter weather is nice.

Check the location of your drain cocks on you Yanmar, see if they drain
all
the lowest points.

I happen to have a small Volvo MD7A here with a cracked exhaust manifold
because this model didn't have a drain cock and it must have frozen the
standing water. Such a drain cock would have saved this nice little
engine.

Now I'm rambling. Sorry.

Steve
s/v Good Intentions

I've seen a light crust of ice on the surface on a calm winter morning. Even
though the sea water temp might get down into the high 30s or 40s, it is the
outside air temp coming in through the ventilators that could freeze an
engine. My engine room is about 80% insulated, down to just above bilge
level, if outside air comes through the vents (always open), it could get
down to freezing.

Since I'm at the dock and paying a flat rate of $60 a month for electric. I
keep a heater going along with a dehumidifier. I maintain a temp. of about
50-60 degrees in the cabin and engine room (door open). This is recommended
to get the dehumidifier to work efficiently. I should mention, it get about
two quarts of water a week even with the boat closed all week. I would guess
about half comes from the air that I let in when I open the hatch and the
remainder through the cabin and engine room vents. I should mention that I
still have some main cabin hull left to insulate, however almost all of my
lockers are now insulated and lined.

Since I started using the humidifier, I haven't had any problem with mold on
books, clothing or bedding.


--
My experience and opinion, FWIW
--
Steve
s/v Good Intentions


"Gordon" wrote in message
...
Steve,
I'd be curious to see how cold it gets near the engine in a sailboat
sitting in Hood Canal in winter. I doubt the temperature of the salt water
gets below 40 F and if the boat is sitting in it, the boat should stay
that
temp. Also seawater freezing temp is about 28.4 F .
I can't see a block freezing and breaking in those conditions,
Now if the boat is on the hard, different story.
Gordon

"Steve" wrote in message
...

"Roger Long" wrote in message
...
Can anyone out there give me some informed and real world (yeah, I know
this is a newsgroup but, hope springs eternal) insight as to how
vulnerable raw water cooled engines are to damage from freezing?


My Volvo is designed for sea water cooling and each cylinder jacket,
manifold and the OEM "water lift muffler" has a drain cock. Seems like a
lot
to remember each fall but these drain every drop of water from the block.
To
prevent these cast iron surfaces from rusting over the winter, I have
three-way sea cock that allows me to pump anti freeze into the system. I
don't actually do this, here in PacNW, since the temp never get that cold
in
my boat (heater) and I like to have the option to go out for you sail
when
the winter weather is nice.

Check the location of your drain cocks on you Yanmar, see if they drain
all
the lowest points.

I happen to have a small Volvo MD7A here with a cracked exhaust manifold
because this model didn't have a drain cock and it must have frozen the
standing water. Such a drain cock would have saved this nice little
engine.

Now I'm rambling. Sorry.

Steve
s/v Good Intentions

That crust of ice is probably fresh water lying on top of the salt water.
Is there a creek or river entering the canal near your moorage? I've seen
that inside the marina at Pt Angeles.
Gordon
"Steve" wrote in message
...
I've seen a light crust of ice on the surface on a calm winter morning.
Even
though the sea water temp might get down into the high 30s or 40s, it is
the
outside air temp coming in through the ventilators that could freeze an
engine. My engine room is about 80% insulated, down to just above bilge
level, if outside air comes through the vents (always open), it could get
down to freezing.

Since I'm at the dock and paying a flat rate of $60 a month for electric.
I
keep a heater going along with a dehumidifier. I maintain a temp. of about
50-60 degrees in the cabin and engine room (door open). This is
recommended
to get the dehumidifier to work efficiently. I should mention, it get
about
two quarts of water a week even with the boat closed all week. I would
guess
about half comes from the air that I let in when I open the hatch and the
remainder through the cabin and engine room vents. I should mention that I
still have some main cabin hull left to insulate, however almost all of my
lockers are now insulated and lined.

Since I started using the humidifier, I haven't had any problem with mold
on
books, clothing or bedding.


--
My experience and opinion, FWIW
--
Steve
s/v Good Intentions


"Gordon" wrote in message
...
Steve,
I'd be curious to see how cold it gets near the engine in a sailboat
sitting in Hood Canal in winter. I doubt the temperature of the salt
water
gets below 40 F and if the boat is sitting in it, the boat should stay
that
temp. Also seawater freezing temp is about 28.4 F .
I can't see a block freezing and breaking in those conditions,
Now if the boat is on the hard, different story.
Gordon

"Steve" wrote in message
...

"Roger Long" wrote in message
...
Can anyone out there give me some informed and real world (yeah, I
know
this is a newsgroup but, hope springs eternal) insight as to how
vulnerable raw water cooled engines are to damage from freezing?


My Volvo is designed for sea water cooling and each cylinder jacket,
manifold and the OEM "water lift muffler" has a drain cock. Seems like
a
lot
to remember each fall but these drain every drop of water from the
block.
To
prevent these cast iron surfaces from rusting over the winter, I have
three-way sea cock that allows me to pump anti freeze into the system.
I
don't actually do this, here in PacNW, since the temp never get that
cold
in
my boat (heater) and I like to have the option to go out for you sail
when
the winter weather is nice.

Check the location of your drain cocks on you Yanmar, see if they drain
all
the lowest points.

I happen to have a small Volvo MD7A here with a cracked exhaust
manifold
because this model didn't have a drain cock and it must have frozen the
standing water. Such a drain cock would have saved this nice little
engine.

Now I'm rambling. Sorry.

Steve
s/v Good Intentions

Could be fresh water, however the entire canal shore line will have this
thin crust. I often drive the So. Shore (SR106)early in the morning and see
this when the air temp is down in the 20s. Once the sun comes up and the
shadow of the have been eliminated, the ice goes away.

Steve
s/v Good Intentions


"Gordon" wrote in message
...
That crust of ice is probably fresh water lying on top of the salt
water.
Is there a creek or river entering the canal near your moorage? I've seen
that inside the marina at Pt Angeles.
Gordon