Engine protection for cold weather

[Garygee]

Hi folks

People with inboard engines know that you must have antifreeze in the freshwater cooling system to stop it freezing.

But what about the saltwater side of the system
A bit of reserch showed that seawater freezes at -2 Deg C.

We are getting tempratures well below -2 Deg C at present and I am sure other places much colder, and I dont want to end up with a big repair bill due to a cracked cooling system

Has anyone ever had problems with the seawater cooling side freezing ? and if so, did it do any damage and is their anyway of stopping it.


Regards Gary

[Mark Halliday]

I finaly got the engine manual from the previous owner yesterday (too late) and it says run the engine for 30 sec after flushing without water supply to empty the pump to avoid cracking the pump housing. I guess this is one area where there is no room for expansion as the water freezes.
On a previous thread it was suggested that flushing in a tub of water/antifreeze mix would work. This also makes sense, for the above reason.
I guess we are both too late now. It was -4ºC at 8:30 this morning on the south coast.

[gingercoastie]

The sea temperature of Penzance this morning was 7.8 deg Centigrade, so I would recomend taking your boat out if you don't want it to freeze.

[Matt]

If I may be so bold, I would suggest that running the engine without water through it can't be doing a world of good for a rubber impeller. Although seagulls don't have rubber impellers and some of those tohatsu's sound similar, so you never know, it might be OK.

[Paul F]

If you can why not stick the leg in a cut down plastic 45 gal butt and chuck a wad of antifreeze in with the water, if you have a sea cock the stick a hose in it and raise butt up and syphen it in whilst running. This way can be done even if boat in water, shut off sea cock disconnect pipe to engine and reconnect butt pipe up.
Hope that may help
Paul

[gavin]

The minute your pump impeller stops rotating the water just drains back down , when stopped the system is under no pressure so any residual water can expand tro the outlet of the impeller pump if it did freeze, its not an issue ,I would be more concerned about a sealed freshwater system having no antifreeze , even if water froze in a pump housing would it not compress the rubber blades while it expands before bursting tro the casing, just leave the leg down in the water where the anodes will protect it and the water pump will be submerged and surrounded by seawater which I have yet to see freeze, in the British Isles

[jwalker]

Gav, you are a nut case.

Make a 'T' in the lowest point of the hoses and attach a drain cock. No water to give you a problem then.

I've done this my Volvo. We can take the discussion further if you need.

[Garygee]

Hi folks


Some good ideas and advise BUT, my RIB spends 100% of its time aflote.

This means that access to the waterpickup, leg etc is just not possible, any draining it is a long job, as like a outboard their are lots of extra bits to drain.

My main concern was it it would ever freeze ?.

Given the hull, leg, waterpickup etc is in the would the engine bay/engine ever got cold enough.

I know the system does not drain back through the water pump as when swapping anodes most of the chambers they are in a full of water when removed.

I see many boats aflote all year round but dont know if anyone has ever had problem is is it but me being over worried.

Am I being over worried, ?.

Regards Gary

[The Garfish]

Originally posted by Garygee
I see many boats aflote all year round but dont know if anyone has ever had problem is is it but me being over worried.

Am I being over worried, ?.

wel itt sownds too mee lyke yew arr wurrid abowt wevver yew arr wurrid enuf

ifn i waz yew i wud bee wurrid abowt dis

gArf