Will my engine freeze in this weather?

[Guest]

I have decided to use my boat this winter and have it berthed on the East coast, with it being so cold I drain the drinking water after use, but what about the engine? Do I need to do anything there or will it be ok? I know that most of the engine is protected as there is a heat exchanger, but what about the sea water from the leg through the impeller to the exchanger?

What does everyone else do? Any advice would be very appreciated.

Andy Coggin.

 

[BarryH]

Sea water freezes at a lower temp than fresh water, thats why the sea dont freeze very often, I left my boat in over a winter period with no ill effects, just make sure that the fresh water in the cooling system is protected.

 

[Guest]

I went down to my boat today (East Coast) which is out of the water.

Everything was frozen - bilge water, water in the kettle etc etc. But I did winterise the engine though.

I have left the boat on my mooring throughout winter on many occasions and have never known seawater to freeze down below.

Providing the fresh water cooling water is up to strength you should be ok. If you are not likely to sail much in the winter you could drain the seawater system after each sail though just to make sure. I am old enough to remember the winter of 1963 which is probably due again soon. Better safe than sorry.

 

[tony_brighton]

If you have a heater on the boat, lift off the engine cover to let the warm air circulate in the engine bay - should help a bit.

 

[Plum]

I have often stayed afloat on the UK East coast without problems over the past 18 years. If your engine is indirectly cooled through a heat exchanger and the engine coolant has the right concentration of antifreeze in it then you will not have to worry until the temperatures get below minus 15 C. The only case where I would worry more is if the boat is moored a long way up a river where there is the chance of a higher concentration of freshwater from land run-off. This will raise the freezing point of the seawater.

 

[ArthurWood]

You might need to drain the seawater lying in the heat exchanger itself. There are probably two drain plugs on it somewhere; one for the coolant and the other for the raw water. It's true that salt water freezes at a lower temp than fresh, but small, static amounts might freeze.

 

[longjohnsilver]

I bet you wrote that reply with a smug grin on your face Arthur - come on upset us all again, how hot is it there?

 

[ArthurWood]

Re: Smug grin

Well actually, no LJS. I was giving an opinion based upon my experience with our first boat, a 19ft with FWC I/O in Atlanta, where we used to get the occasional hard frost. No salt water, however, just a big lake- 45 mi long and 550 miles of shoreline-but not quite as big as the Great Lakes! The boat was stored on a rack and I simply drained the raw water section of the heat exchanger each time it was put away. The Marina manager said he only kept the place open in winter for us crazy Brits because we were the only ones who would venture out onto the lake at that time of year. As for temps here, it's been a bit cool the past few days; we even turned on the heating for a few hours; yesterday just reached 11C, this morning it was 8C and now it's 20C so we have patio doors wide open. Just done 16mi on my bike and worked up quite a sweat at an av 15mph. Did 34mi on our tandem yesterday at av 16.7 mph, but no sweat. There's more to life than boating, but the Gulf is calm, one or two boats out there, red tide has gone.......What else can I bore you with?

 

[coliholic]

Re: Smug grin

Huh, well it might sound OKish in Florida but just think, you're missing the Boat Show. We've ALL been and we've got lots of exciting stuff to talk about but we're not telling you about it, so there.

 

[LadyInBed]

I went down and checked my boat today (it winters in the water) – all ok I reset the cabin Max/Min thermometer and noted that the temp had got down to –6.

I guess that if water freezes in flexible pipes, the pipes should expand OK. Or is this just wishful thinking?

 

[Guest]

If you are marina based install a tubular heater in the engine bay coupled to a frost protected thermostat - all available from electrical wholesalers like TLC. They only draw 60watts per foot so are cheap to run. Remember also that when draining the drinking water running the tank dry by opening all the taps is not enough. I do this to start then 'crack' the pump by releasing the screws normally at the bottom or side. On my 28' boat with a hot water system and a tank size of 35 galls I removed another 3 galls which is distributed around the system of pipes etc.

 

[ArthurWood]

Re: Smug grin

Well we went to the Ft Lauderdale Boat Show where it was sunny, warm and in the fresh air, so there. AND we would normally go the Miami Boat Show, but we shall be on a cruise in S. America, where it will also be warm until we get to Cape Horn and the Falkies. But I'm not telling you about that either.

 

[Guest]

Thanks for all your replies NM

NM

 

[Scubadoo]

Hi,

My boat is also in the water, I don't think you need to worry about the engine providing you have antifreeze in the coolant.

I keep my drinking water tank empty and carry those Buxton 3litre water containers to cover basics. I also keep two Oil filled Rads on (600watt Mini) - one in the engine bay and one in the cabin, so far the temp has not been below 6c. Also keep dehum crystals and no damp around 30/40%.

RM.

 

[mldpt]

As well as all the above I draw a mixture of antifreeze and water through the raw water sysem to make sure the heat exchanger and gearbox cooler dont freeze, then there is no need to have heat onboard. Last year I forgot to leave the water taps over the sink open and they froze pushing the swivel top pipe off, I was able to mend it but i WONT FORGET AGAIN.