Winterising Engine - Raw Water cooled, boat afloat

[Mulge]

This year I have decided to keep the boat afloat so that I can take advantage of the odd day when the sun shines, a gentle breeze blows and I'm not at work, to get some sailing in. I'll take off the new sails, bend on the old ones and double up the lines so that the boat is well prepared for a storm or two. What stumps me is how to prepare the raw water cooled VP 2002 engine for sub zero temperatures and still be able to sail when I want to. Use of the engine to get in and out of the marina is a must, but it may only run for a few minutes each trip.

Normally I take out the thermostat and run an anti-freeze mixture through the engine and leave it standing over winter. Is there any alternative to doing this each time I come in from a short day sail? Any ideas gratefully considered.

Mark

 

[tillergirl]

Does one take it that the marina water is fresh? In which case I can't see any choice to glugging in some anti freeze. If its salt, it has to get pretty cold. Blanket over engine and an oil heater on a timer?

 

[fireball]

What you need to do is stop the water from freezing in the pipes/engine ... if it is salt water then you've got a lower freezing point anyway .... so all you need to do is keep the engine warmer ... got a little heater?

We were in a marina a couple of years ago, the water had surface ice on, but it didn't stop us from using the boat ....

 

[Twister_Ken]

How would it be if you closed the cooling water intake maybe 30 seconds before turning off the engine? Would this blow most of the water through, leaving the block more or less 'dry'? If so any residual water would have room to expand if it froze without cracking anything.

Needs someone with more mechanical knowledge than me to say if this is actually a workable solution.

 

[matelot]

If you are moored in salt water then the obvious question is - does the sea freeze over where you are? If not, dont worry

Much the same question arises if you moor in fresh water as we do. Here in south wales it rarely gets that cold so I didnt bother doing anything to protect the engine

In practise, it has to be well frozen outside for the engine to be damaged by ice inside the boat, but it can happen. A small greenhouse heater running 24/7 would help. Other than that, you take a risk.

You are just as likely to do damage by running the engine just to get in / out of the marina. You should always run it long enough to get the oil to operating temperature.

 

[kacecar]

Hi Mulge

Like the other posters, I doubt if you will have much of a problem while its in the water.

Someone has already suggested a greenhouse heater. These have the advantages of taking relatively little power and of some being thermostatically controlled. However, they are rather large and, if your engine compartment is anything like mine, you risk wasting energy heating up an empty boat when all you really wanted to do was to keep the engine above zero.

I suggest a low wattage light bulb, 25w will do, kept on all winter underneath the engine. As far as this layman is concerned, one of these will last for a good many weeks and keep the engine just warm enough. I used this approach (and two bulbs) while my boat was on the hard last year - just in case my attempt at draining the engine had been unsuccessful. No problems were encountered despite some very cold temperatures in Jan/Feb.

 

[Flossdog]

I don't know about Haringvliet but I used to have a boat on the Isseljmeer and that in some years froze completely over so that people could drive across it - 30km!! Talk to the locals and see what the danger is. If you are the only one planning to be in the water then you may like to rethink the idea.

 

[chiefeng]

Closing the sea cock will only blow the residual water out of the exhaust, the block will stay full.
There is a drain plug at the stbd aft end of the engine just above the starter motor if you really want to be sure, but otherwise i wouldn't worry.
Rgds
Bob

 

[Mulge]

Many thanks for all the replies.

Apparently 70% of the Rhine's water goes through the Haringvliet to the sea and there is some flow of water through the marina so icing over up is unlikely in a normal winter. If something worse is threatened I'll take up one or more of the proactive suggestions, but otherwise take comfort from those in the no need to do anything category!

Mark

 

[Stemar]

The inside of your boat is a fairly big volume of air and the engine compartment has at least as much surface in contact with the water as it does outside air, so it's going to have to get SERIOUSLY cold for several days before you run any risks of freezing water in the engine.

If you're close enough to the boat for this to be feasible, I'd not worry until you have had day time temperatures below freezing for a few days (-10, go sooner!) then just go and run the engine for an hour. That'll charge up the batteries as well, chase damp out of the electrics and generally do everything a bit of good.

Lots of people say it's best to run it in gear pulling against the mooring lines. I've seen arguments for and against, but that's a debate for another thread!

 

[vyv_cox]

I didn't realise that you were on the Haringvliet until somebody else made the point. I kept my boat at Hellevoetsluis (Arie de Boom)for seven years, most winters left afloat. Twice during this time the dock froze over to the extent that we had skaters around the boats. I was told that the ice was more than 30 cm thick on the first of these occasions. Despite this, our raw-water cooled Bukh came to absolutely no harm, no special precautions and definitely no antifreeze or anything else pumped through. Also, neither we nor anyone else suffered any hull damage in these extreme conditions.

 

[curious]

My boat has a Bukh 20 and usually over winters in Haslar Creek. I have agonised over the question of whether to get an anti-freeze solution into the raw water around the engine or not bother. Winters in the south have been mild of late but the current cold snap revives the issue. For various reasons this year, the engine has not been "anti-freezed". I am taking comfort from the experience of those who have posted comment having boats overwintering without protection in water at much lower temperatures than now experienced in the UK. And I note there appeared to be sea ice on the shore in Dorset this last week. Are there any marine engineers out there with experience of this situation who can tell tales of frost damaged engines?

 

[Wunja]

My boat is in Noordschans on the other side of the Haringvliet bridge. Last week there was a lot of ice between the pontoons and some water in my lazarette locker had frozen.
My boat was in the water last winter and I disconnected the intake from the seacock and ran anti freeze through the system, catching and re-cycling it via a bucket under the exhaust. A bit of a palaver and expense if you intend to use the boat through the winter.