Winterising a boat afloat

[kalanka]

I usually store my boat ashore in the winter but this year I plan to stay afloat on her mooring off Loch Linnhe a little south of Fort William.

Sadler 34 with VP 2003 freshwater cooled.

I cannot decide how much winterising to do for when winter proper starts in November/December. It is clear that the sea on which she floats will moderate the temperatures compared to a boat ashore, particularly for the sea water intake and through hull fittings. The loch contents are constantly being renewed since it is strongly tidal.

Recent winters in the Highlands have been mild but it would far from impossible to get air temperatures as low as - 20 C or lower, possibly over several days.

I shall winterise the domestic water supply as usual but am undecided whether to run antifreeze through the raw water system and the heat exchanger as I did when storing ashore.

I hope to do some sailing in the next couple of months and when we get a quiet spell during the winter but the more winterising I do the less likely is the latter to occur...

I would be glad to learn your experiences of how boats afloat cope with frost.

 

[vyv_cox]

When we lived in Holland we berthed on fresh water in the Haringvliet. In several winters the water froze, in one year to a depth of 30 cm. The temperature never rose above -10C throughout January. I was talking to the harbourmaster after the big freeze, when people were skating throughout the marina, who told me that he had not heard of any engine damage as a result of freezing.

Subsequently we never winterised the engine(s), initially a raw-water cooled Bukh and later a fresh water cooled Yanmar.

 

[NormanS]

Wow! You'll need to be very sure of your mooring there. The prevailing SWlies blow right up the loch, so there's a big fetch at Fort William. I don't know if any insurance company will give you winter cover on a mooring there.

 

[EdWingfield]

I always leave my boat afloat. This winter in the lower Clyde in seawater. Gulf Stream keeps the sea 'warm'. Frosts are rare. I seal up the boat like Pharoah's tomb and use 4 of those moisture removers at £1 each.

 

[NormanS]

When we lived in Holland we berthed on fresh water in the Haringvliet. In several winters the water froze, in one year to a depth of 30 cm. The temperature never rose above -10C throughout January. I was talking to the harbourmaster after the big freeze, when people were skating throughout the marina, who told me that he had not heard of any engine damage as a result of freezing.

Subsequently we never winterised the engine(s), initially a raw-water cooled Bukh and later a fresh water cooled Yanmar.

I used to winter my previous boat in the Caledonian Canal. One winter there was a cold spell, and a large old fishing boat being converted, sank, because a cooling hose attached to an open seacock froze. The frozen hose pulled off the stem on the seacock, presumably because of the expansion, so when it thawed again, water poured in and the boat sank. Another boat close by, had similar damage but was spotted before she sank.

 

[Halo]

Sadler 34 is a nice boat. If you leave her afloat in the wettest area in the uk I expect she will be mouldy and dank by spring no matter how much ventilation you arrange. Are you hoping to use her in winter or just looking to save money? If the latter I expect it won't be worth it.

 

[prv]

Sadler 34 is a nice boat. If you leave her afloat in the wettest area in the uk I expect she will be mouldy and dank by spring no matter how much ventilation you arrange.

Why would she be any less dank after standing in a yard in the wettest area in the UK?

Pete

 

[johnalison]

Why would she be any less dank after standing in a yard in the wettest area in the UK?

Pete

I do generally find that a boat laid up ashore in the driest area of the UK stays drier than one afloat, though the chance of freezing is much higher.

 

[peteK]

If there is antifreeze in the engine why worry, do you winterise your car ? I have never winterised a boat but I am in North Wales were it never really gets that cold.

 

[prv]

If there is antifreeze in the engine why worry, do you winterise your car ?

Does your car pull raw water through its radiator instead of air?

The engine block itself has anti-freeze in, but the heat-exchanger and its plumbing, and any traps in the exhaust system, will contain seawater.

I won't be winterising mine, but I live on the south coast where anything more than a hard frost in the morning is rare. The OP is up in the frozen North and contemplating minus 20.

Pete

 

[kalanka]

To respond to some of the points made:

The mooring is actually in a sheltered bay in a side loch from L Linnhe. It is very robust. Insurers are content.

The difference is that my car does not have a water supply unprotected by antifreeze like the raw water circuit for my engine. That is the primary issue - will that freeze when the boat is afloat and air temp has been at -20 for four days? Vyv's post answers that as far as -10 is concerned. Any offers for lower temps?

 

[dunedin]

The only winterisation we used to do when afloat on the Clyde was depressurising the domestic water system when we left the boat, and extra sail ties on the furling job. Using the boat monthly is the best approach IMHO.

 

[Halo]

Why would she be any less dank after standing in a yard in the wettest area in the UK?

Pete

Because there is electric in most boat yards and you can use a dehumidifier. Not possible on a mooring.

 

[Quandary]

Because there is electric in most boat yards and you can use a dehumidifier. Not possible on a mooring.

I prefer ventilation in this climate which works as well afloat as ashore. There are loads of folk including some in our club yard burning electricity all winter in an effort to de-humidify Scotland but so far it seems as damp as ever.

 

[LittleSister]

There are loads of folk including some in our club yard burning electricity all winter in an effort to de-humidify Scotland but so far it seems as damp as ever.

 

[johnalison]

We found, on asking around, that the solution to this problem among fellow HR owners was to shove socks into the ventilators. It would be possible to remove the cowls and put caps over the holes but we are a lazy bunch.

 

[Gunfleet]

There are loads of folk including some in our club yard burning electricity all winter in an effort to de-humidify Scotland but so far it seems as damp as ever.

made me laugh too

 

[Halo]

There are loads of folk including some in our club yard burning electricity all winter in an effort to de-humidify Scotland but so far it seems as damp as ever.

Nice one ! Made me smile and I agree there are people who don't realise you need to seal her up to allow a dehumidifier to work.
Part of my sealing up routine is to seal the head bowl with cling film. One of my crew saw me doing this and said " Blimey I bet the bloke who invented cling film didn't think of that application". For some reason everyone on board thought this was funny. It's certainly fun if you forget to remove it !

 

[knuterikt]

To respond to some of the points made:

The mooring is actually in a sheltered bay in a side loch from L Linnhe. It is very robust. Insurers are content.

The difference is that my car does not have a water supply unprotected by antifreeze like the raw water circuit for my engine. That is the primary issue - will that freeze when the boat is afloat and air temp has been at -20 for four days? Vyv's post answers that as far as -10 is concerned. Any offers for lower temps?

-20 for some days and sea water inside the boat will freeze.
I have had frozen water in the bilge.
I blew the fuse on my bilge pump mounted on the wall in engine room (membrane pump) in February 2016 because it was frozen, thawed pump and replaced fuse and it worked again.
I always put antifreeze in the sea water circuit.
Easy to do through sea water filter.

 

[vyv_cox]

The engine block itself has anti-freeze in, but the heat-exchanger and its plumbing, and any traps in the exhaust system, will contain seawater.

Having inspected my Yanmar 3GM30F quite carefully I cannot see that any water will remain in any part of the seawater cooling system provided that the water pump has been opened. The only metal is the heat exchanger itself, which is at almost the highest point and will drain itself. All the plumbing is rubber hoses.

I agree about the trap and in the past I have drained this, although I am not sure it was strictly necessary.

I always drain the calorifier, even in Greece where it is never going to freeze (where my boat is). Over the winter the hot water becomes quite coloured if left in.