Winter sailing - protecting engine from frost / freezing

[PhillM]

This is the first year I plan to keep the boat in and sail occasionally in the winter. My beta manual says to protect the sea water side of the engine with anti-freeze. But if I want to use the boat, this isn't going to work,. is it? What do you do to keep your engine from risk of freezing but still usable in the winter?

 

[vyv_cox]

The majority of seawater in an indirectly cooled engine will run into the exhaust trap when it stops, assuming you have an anti-siphon vent at the highest point. There will be a small amount in the hose between the pump and the vent, but on many engines this is all rubber, except for the pump itself, and freezing is unlikely to harm it. Draining the exhaust trap will release any significant volume of water into the bilge, where it can be pumped overboard. If you are concerned about the water in the pump you could release the faceplate screws to drain it.

 

[cliff]

Duh, Solent, sea ice? don't think so - salt water does not freeze 'til way below zero - raw water side of the engine will be fine in UK waters - make sure you have sufficient anti freeze in the freshwater side though.
I would be more concerned about the fresh water onboard in your fresh water tank and piping, filters etc - I have had the charcoal filter split due to freezing - raw water cooled engine was fine.
Air temp below 0°C sea temp above 0°C - fresh water tank (moulded against the hull below water line) did not freeze but the filter below the gally sinks did.

 

[l'escargot]

A boat in the water, in the Solent, is unlikely to freeze. When did you last see the sea freeze? You would need quite a few days of sub zero temperatures before you need to be concerned.

 

[PhillM]

Thanks chaps. Looks like I'm taking the manufacturers manual too seriously. I keep a frost heater on all winter and that is next to the engine, so I guess that will be fine.

As for sea ice, point taken. I had not quite seen the conenction.

 

[prv]

They're talking about a boat propped up on sticks in a cold and windswept boatyard. I can believe that a small pocket of seawater might freeze in those conditions. But not a boat that's sat in the sea.

The freshwater side ought to be fine even without your tube heater, as it should be mixed with "antifreeze" for its corrosion-inhibiting properties.

Pete

 

[vyv_cox]

They're talking about a boat propped up on sticks in a cold and windswept boatyard.

I don't think so. He says he plans to leave it in the water.

 

[dylanwinter]

They're talking about a boat propped up on sticks in a cold and windswept boatyard. I can believe that a small pocket of seawater might freeze in those conditions. But not a boat that's sat in the sea.

The freshwater side ought to be fine even without your tube heater, as it should be mixed with "antifreeze" for its corrosion-inhibiting properties.

Pete

the beast in the bowells of the slug was fine for five winters

no worries mate

 

[maby]

Duh, Solent, sea ice? don't think so - salt water does not freeze 'til way below zero - raw water side of the engine will be fine in UK waters - make sure you have sufficient anti freeze in the freshwater side though.
I would be more concerned about the fresh water onboard in your fresh water tank and piping, filters etc - I have had the charcoal filter split due to freezing - raw water cooled engine was fine.
Air temp below 0°C sea temp above 0°C - fresh water tank (moulded against the hull below water line) did not freeze but the filter below the gally sinks did.

The freezing point of sea water is not that low, you know :

"Ocean water with a typical salinity of 35 parts per thousand freezes only at −1.8°C (28.9°F). So if there were no halocline in the polar oceans, then the cooled top ocean layer, being denser, would sink into the deep ocean, in the same way as thunderstorm clouds rise in the atmosphere, and the entire ocean column would have to cool to −1.8°C before its surface could freeze.

Read more: http://www.waterencyclopedia.com/Re-St/Sea-Water-Freezing-of.html#ixzz2hDKTUs6O"

We can easily get those temperatures round the south coast of Britain several times in the winter. The protection is mostly a question of the boat being afloat in the sea and the sheer volume of water surrounding it providing a reservoir of warmth that takes a long time to be exhausted. You need to consider the layout of your boat - an inboard engine inside an insulated compartment will take quite a long time to freeze but an outboard or a small engine in a compartment that is not well insulated or draft proofed could suffer after a relatively short period of sub-zero temperatures.

 

[JumbleDuck]

The freezing point of sea water is not that low, you know :

"Ocean water with a typical salinity of 35 parts per thousand freezes only at −1.8°C (28.9°F).

Up here in Scotland (but the southernmost bit of Scotland) it is very common to see frozen seawater during the winter. You see it on beaches as the tide goes out - as the water gets shallow there is less thermal reservoir and the top layer solidifies, lying as a layer of ice on the beach until the tide comes in again.

 

[Ru88ell]

Phill

Yesterday I was at Sea Start, Hamble Point, for their RYA Diesel Engine course. I've inherited a Beta 20 in the new boat so wanted to know what to do with it. I went from total diesel engine numpty to being able to service it, troubleshoot it, and winterise it if necessary. I'd seriously recommend it, especially as it's only up the road from you.

 

[Caer Urfa]

This is the first year I plan to keep the boat in and sail occasionally in the winter. My beta manual says to protect the sea water side of the engine with anti-freeze. But if I want to use the boat, this isn't going to work,. is it? What do you do to keep your engine from risk of freezing but still usable in the winter?

I have sailed 'all year round' for years as you can get some very nice days in winter, even two year ago in -14C winds offshore.

All I make sure of is that the antifreeze is up to strength and and all hoses are in good condition.

However our sea marina freezes at times as we do get some fresh water discharge into it at times, One warning though do not even think about moving your boat through even thin ice as you will cut the GRP hull to pieces, saw a wooden trawler do it two year ago, and you would not believe what 6mm sheet ice can do even to a wooden hull 25mm thick, yes the boat started sinking and only because they got the boatyard hoist working did they save the boat.

PS :Yes I do also have a tubular heater in the engine bay set for -2 degrees to come on as if your engine bay is reasonably insulted for sound reasons this also help protect the engine bay from the cold.

Mike

 

[Jaguar 25]

Winter sailing with outboard engine

The freezing point of sea water is not that low, you know :

- an inboard engine inside an insulated compartment will take quite a long time to freeze but an outboard or a small engine in a compartment that is not well insulated or draft proofed could suffer after a relatively short period of sub-zero temperatures.

So, a follow on question if you please. We will be keeping our boat in the water (Liverpool marina) over the coming winter. It has an outboard that is obviously more exposed than an inboard. My assumption is that the cooling water drains with needing to do anything apart from stop the engine. Is this true or will there still be some residual amounts of water within the engine that has the potential to freeze and cause a problem?

Any advice would be welcomed.

 

[maby]

So, a follow on question if you please. We will be keeping our boat in the water (Liverpool marina) over the coming winter. It has an outboard that is obviously more exposed than an inboard. My assumption is that the cooling water drains with needing to do anything apart from stop the engine. Is this true or will there still be some residual amounts of water within the engine that has the potential to freeze and cause a problem?

Any advice would be welcomed.

I honestly don't know - we use an air-cooled Honda - specifically to avoid such questions.

 

[PhillM]

Phill

Yesterday I was at Sea Start, Hamble Point, for their RYA Diesel Engine course. I've inherited a Beta 20 in the new boat so wanted to know what to do with it. I went from total diesel engine numpty to being able to service it, troubleshoot it, and winterise it if necessary. I'd seriously recommend it, especially as it's only up the road from you.

Thanks Ru88ell, Thanks for the tip. I'm on the Stormforce course on Saturday but I wanted to ask here for practicle advice rather than the "official" version.

 

[knuterikt]

One warning though do not even think about moving your boat through even thin ice as you will cut the GRP hull to pieces, saw a wooden trawler do it two year ago, and you would not believe what 6mm sheet ice can do even to a wooden hull 25mm thick, yes the boat started sinking and only because they got the boatyard hoist working did they save the boat.

Thin ice will cut through the planking of a wooden boat in short time if you go through it (the thin new ice is worse than thicker ice)

GRP boats on the other hand can go in ice without any problem as long as you don't need to ram the ice to break it.
The bottom paint will get rubbed of but apart from that there is no problem as long as you go slow.
look at this video http://www.youtube.com/watch?v=aub7d4QKdOY

 

[Gwylan]

We had the sea freeze on a number of occasions during our time in the Netherlands. Locals recommend pouring diluted anti freeze into the strainer and sort of cut the engine as it starts to exit to the sea. Bit arbitrary when you are on your own and not too environmentally friendly.
Just have to carry more anti freeze to fill after you have used the boat.

Obviously have to make sure that the closed cycle of the system is well stocked with a-f

It did get cold enough to freeze the water system and broke the sink tap! That was a real pain. We run the fresh water system dry once frost and snow looks likely.

 

[[3889]]

Up here in Scotland (but the southernmost bit of Scotland) it is very common to see frozen seawater during the winter. You see it on beaches as the tide goes out - as the water gets shallow there is less thermal reservoir and the top layer solidifies, lying as a layer of ice on the beach until the tide comes in again.

I suspect what you see is a layer of frozen dew, lifted off the beach by the incoming tide and concentrated at the strand line. At least a week of -10C temps is required for any open marine water to begin to freeze.

 

[Bilgediver]

The sea water surrounding the hull rarely reaches freezing temperatures and acts a s a blanket around the hull . Put a thermometer
in your engine space for the winter and you may be surprised at what it shows. Engine freezing may be the least of your problems however
this might not be the case regarding fresh water systems elsewhere in the boat.

If you use a gardeners thermometer then it will actually record the lowest temperature it is exposed to.

 

[l'escargot]

I've got a max/min thermometer on my boat. It seldom dipped below freezing last year.