Winterising Engine Raw Water Side

[Ruffles]

Of course, the (possibly toxic) anti-freeze then gets chucked onto the earth and gravel hard-standing, but I'm sure it's had much nastier stuff soaking into it over half a century of use as a yacht yard.

Not many weeds growing in boat yards, even in Summer!

 

[wotayottie]

I'm moored in fresh and I leave the boat in through the winter. A couple of years ago when we had that really cold winter the water round the waterline froze - one member was daft enough to try to walk on it, unsuccessfully. Anyway the fresh water side of the engine did not freeze up

Its sense to try and protect yourself but it isnt a great risk in the UK and certainly not in salt water. More of a risk out of the water of course.

 

[webcraft]

.
We've never winterised the freshwater side of the engine, in or out of the water. I would never bother doing it with the boat in the water, however we aer on the hard this Winter and it has been down to -8 already so I am thinking of doing it this year.

What exactly is the procedure, hose jammed in the seawater intake with the other end in a bucket of 50/50 water and antifreeze and run engine 'till it comes out blue from the exhaust then shut the seacock?

Anything else anyone would recommend?

- W

 

[Kelpie]

Nick
that's basically what we did. Took the hose off the raw water filter and set it up so that the impeller was sucking from a bucket of 50/50. Needs to be the right size/shape of bucket so that it can be safely wedged/held in place with one hand and not risk coming into contact with the moving belt.
Started the engine at idle revs, to avoid it sucking up too much of the mixture, and I shut it off when the bucket was approaching empty- which was about the same moment, fortunately, that SWMBO shouted from outside that blue stuff was coming out of the exhaust.
Hard to say exactly how much antifreeze mix I used doing this, but it's probably close to ten litres.
The engine sucks the stuff up at an alarming rate- the whole process was over in a few seconds.

 

[EuanMcKenzie]

my boat is in the water at Largs and I've left the salt side alone and winterised the fresh side.

Also drained down the water tank and domestic water system

Can't see salt water freezing.

Its different at kip where the burn runs into the marina and makes it more brackish.

I think its more to do with the water your boat sits in than its location i.e. salt content

 

[webcraft]

Hard to say exactly how much antifreeze mix I used doing this, but it's probably close to ten litres.
The engine sucks the stuff up at an alarming rate- the whole process was over in a few seconds.

Ten litres of 50/50 is a lot of antifreeze . . .

I'm not so worrired about frost but prob good to have antifreeze (anticorrosive) in the heat exchanger.

Did you do anything else winterizey?

- W

 

[single]

My boat stays in (fresh) water all year round. I treat the raw water side always. Compared to some of the other jobs on the boat it is easy to do and for peace of mind it costs nothing.

HF

How is it easy? I can't think of an easy way after each use.Don't some people just shut the inlet cock a few seconds before shutting the engine down?

 

[Kelpie]

Ten litres of 50/50 is a lot of antifreeze . . .

I'm not so worrired about frost but prob good to have antifreeze (anticorrosive) in the heat exchanger.

Did you do anything else winterizey?

- W

Yes, it is rather a lot of antifreeze... a few quid anyway, but if it's good for the engine...

The only other thing I did was to take the belt off, I thought it might be good for it to relax. Plus the usual oil, anode, and levels checks.

 

[Ruffles]

Anything else anyone would recommend?

I flush the raw water side with the engine off and the boat on the hard.
I remove the hoses from the syphon break so that I have access to the top of the exhaust circuit.
Then place a bucket under the exhaust and pour 50/50 antifreeze downstream until the bucket is full. I repeat a few times then blow the remaining fluid out.
On the upstream side I close the sea cock and fill the system with AF. Then open the sea cock to drain it out. Repeat a couple of times and, again, blow the remaining fluid out so that the gearbox is empty.
I find this quick and cheap to do. And I can do the exhaust side with the boat in the water if I think the engine won't be used for a while. This way I haven't had to replace the exhaust manifold for five years.

 

[macnorton]

Where do you get free antitfreeze from?

A car breakers , they have to pay to get rid of the stuff!

 

[alahol2]

Many years ago I was given several litres of 'winterising mix' which consisted of water, antifreeze and engine oil. Every year I set up a 'closed circuit' with a bucket of the stuff under the exhaust outlet and a hose from the bucket to the engine cooling water inlet. I run the engine for several minutes then turn the inlet seacock off before stopping the engine. Seems to work OK and I still have a few litres left.
Does anyone else add engine oil to the mix? Anyone see any drawbacks?

 

[Ruffles]

Anyone see any drawbacks?

Antifreeze already has corrosion inhibitors in it. And would the oil actually stick to wet metal surfaces?

 

[Ricd]

Thanks for all the advice. Have now been to boat, changed oil and oil filter, greesed various bits, emptied water tank and drained down calorifier, sprayed a bit of WD40 around electrics but have decided this year for the first time ever, not to put 50/50 antifreeze into the raw water side while the boat is still in the salty stuff.

I accept the anti-corrosive properties of antifreeze but given that the raw water side is in salt water for at least 8 months a year I wounder what the actual benefit of a the month or two with anti-freeze