Have I left it too late ....

[Wunja]

I'm really puzzled as to why so many people seem to want put antifreeze through the raw water system of a freshwater cooled engine instead of draining it.

It depends on how effective draining is, can you get all the raw water out of the heat exchanger, exhaust and other bits?

My technique requires a 13 year old boy (has been successful with an 11 yo!). I take the top of the internal strainer, son starts the engine, then looks over the stern at the water coming out of the exhaust.
As the water gets sucked out of the strainer I replace it with antifreeze from a 5 litre bottle. As soon as my son sees pink water coming out of the exhaust he turns the engine off.
The remaining half litre of anti freeze gets pumped through the toilet.
Because the AF will end up in the water I use one that can be used in potable water systems - hopefully it doesn't kill off too much.

 

[JokersWild]

Checking understanding

Right - went to boat - no neighbours to pick brains. So have taken pictures of the bits I think I need to attack! I think I can use the method suggested by the theoldsalt and Wunja. Quite keen to avoid taking hoses off things, as I don't trust myself to do jubilee clips up again properly afterwards!

So the raw water inlet in first picture below is currently open, so I need to close this first. Then fill up the strainer (second picture) with part of a 5L bottle of fairly environmentally friendly anti-freeze (as seacock was open at hoist, so assume at least some water drained out and some is needed to fill the system back up. In fact I could probably refill with just freshwater initially). Then start engine (inlet seacock still closed) and keep topping up strainer with anti-freeze until the person who has turned on the engine sees pink liquid coming out of exhaust and can then turn the engine off again. When finished, reopen the seacock (as suggested by davewarburton).

If this is right, then I reckon I can do it!

 

[Plevier]

It depends on how effective draining is, can you get all the raw water out of the heat exchanger, exhaust and other bits?

Yes!
Heat exchanger on top of engine, hoses from both sides slope down.
Raw water pump is at lowest point of piping before heat exchanger.
Seacock is straight below strainer.
Vetus water trap (same as in OP's photo) has a drain point on it.
Exhaust rises to rear from trap, over a single high point to outlet. It's rubber anyway.
No water cooling to gearbox.
No problem!

 

[Twister_Ken]

Beware running engine ashore if you are propped up, and not in a cradle. Vibes from running the engine MIGHT shake shores and props loose.

 

[JokersWild]

Oh no Ken, now I'm worried about boat falling off wooden props as well as breaking the engine! I'll ask the yard manager chap if it's safe enough to risk this.

 

[mikemonty]

Before you start to dig out the "shock horror" smilies, please consider that I'm still in my first boat owning season.

Boat hoisted out last week for a short rest ashore, check of hull, polishing etc etc. I've looked through various wintering lists and followed most tips. Obviously I motored over to the hoist though, so I don't understand what to do with any raw water still in the engine system? Various advice talks about draining it, or flushing through with anti-freeze. Obviously I couldn't do this before hoisted, so how do I do it now she's ashore?

Sorry if this is a really thick question.

I just winterised my 1GM10 on the hard today.
I put a bucket of fresh water under the exhaust outlet and run a siphon (garden hose) back to the water pump through the cockpit and into the cabin.
The water level in the bucket is roughly at the normal waterline.
Run the engine and the water will go round the circuit. (might have to top up occasionally as some of the exhaust water will probably miss the bucket.)
As the water gets warm I replace with cool or start introducing antifreeze into the circuit by pouring it into the bucket.
When happy that I have a sufficient concentration of antifreeze - and that the water has gone through the thermostat for long enough - shut down, clear up, and go home.
I'm in the position that by the time I reach my winter lay-up the boat is in brackish water anyway so I don't bother too much about salt concentration, but a few changes of water in the bucket (don't break the siphon!) should be OK.

 

[alahol2]

Once you have got the engine warm by running the antifreeze it is the ideal time to pump out the engine oil (if you intend to change it). It's a whole lot harder to pump when it's cold.

 

[colhel]

Not seen any neighbours yet. Might pop back today and loiter! Am fairly happy with freshwater side. Will have a nose and see if I'm feeling brave enough to do raw water side. Might be able to suss it better with your comments and the engine in front of me!

Have the answers caused confusion or have they helped?

I see you're on Poole Scuttlebut. Good man

 

[JokersWild]

Update ....

Answers have helped a lot ... until Ken scared me a bit that I might be able to actually make her fall off the wooden stilts! I think it's unlikely, but just another worry! So my plan now is to get a proper mechanic down to do this with me this year, and watch them do it, so that I can do it myself next year. Will be interesting to see if they go for the flush with anti-freeze option or drain down option, as this has been debated on here a bit. I will update this thread out of interest afterwards. Will get a bit of a service / oil change etc at the same time, so I know this is the PBO forum, but sometimes I'm not very practical, and at least I will be an expert next year! Mechanic booked for Friday, sub zero temperatures of course now forecast, especially Thursday night. Fingers crossed no burst pipes in the next couple of days. Have an electric heater on board that came with the boat and I've never used, so now I need to decide whether to get shore power for a few days and get this plugged in to take the edge off a bit. But then I can add the worry of her catching fire from dodgy electrical thingy??!!

Yes - considering Poole - we need to get past The Needles this year. Not too much of a worry for me, but crew never been outside Solent. And I would like the social side of the event too.

PS - not a "good man" - I am a "good lady"

 

[jimi]

I've got the same boat and engine as you. In 12 years of ownership I have never drained the engine. The engine has antifreeze mix in it , and I add a bit of insurance by leaving a small oil heater on thermostat switched on if cold weather is forecast. Must admit I leave the boat in the water as I see absolutely no benefit in lifting out over the winter as I'm in a marina.

 

[alahol2]

I've got the same boat and engine as you. In 12 years of ownership I have never drained the engine.

It may be time to drain and refill then. Most antifreeze mixes quote 3 - 5 years before the anti-corrosive additives become ineffective.

 

[jimi]

It may be time to drain and refill then. Most antifreeze mixes quote 3 - 5 years before the anti-corrosive additives become ineffective.

I get a major service done by a dealer every 3 years or so where that is done. In between I change oil,filters, impellers myself.

 

[vyv_cox]

I'm really puzzled as to why so many people seem to want put antifreeze through the raw water system of a freshwater cooled engine instead of draining it.
Is this Yanmar specific, is there part of the system you can't drain for some reason?
It's very easy on the VP2020 engine. You do of course need to be able to drain the exhaust water trap as well. Mine (Vetus) has a drain point on it.

You are exactly correct. It is totally pointless adding antifreeze to the seawater side of an intermediately-cooled engine. The total length of the seawater side of a Yanmar GM30F comprises the hose from the skin fitting, the pump, rubber hose to the heat exchanger, the stainless steel heat exchanger, the exhaust hose, plastic trap, more hose and maybe a plastic silencer. So what is antifreeze going to protect? By opening the pump you drain the heat exchanger, by draining the trap you remove any remaining water that might freeze. There is nothing there that will be protected by the corrosion inhibitor in the antifreeze.

It does no harm, and maybe some good, to flush with fresh water but adding antifreeze is money down the drain. Empty hoses and heat exchangers don't freeze.

Not for the freshwater side of course, which should be changed every three years or so with 50/50 antifreeze.

 

[Ruffles]

It does no harm, and maybe some good, to flush with fresh water but adding antifreeze is money down the drain. Empty hoses and heat exchangers don't freeze.

On our MD2030 the high rise exhaust manifold remains full of salt water. Which is why I've had to replace it twice! Purely through corrosion rather than freezing.

 

[vyv_cox]

On our MD2030 the high rise exhaust manifold remains full of salt water. Which is why I've had to replace it twice! Purely through corrosion rather than freezing.

Drain it down! Air doesn't feeze. The trap may have a tap, otherwise take a hose off.

 

[Plevier]

On our MD2030 the high rise exhaust manifold remains full of salt water. Which is why I've had to replace it twice! Purely through corrosion rather than freezing.

Like this http://www.marinepartseurope.com/en/volvo-penta-explodedview-7740690-25-4166.aspx ?
Can't quite follow the drawing. Can't you drain it?

 

[colhel]

I'm really puzzled as to why so many people seem to want put antifreeze through the raw water system of a freshwater cooled engine instead of draining it.
Is this Yanmar specific, is there part of the system you can't drain for some reason?
It's very easy on the VP2020 engine. You do of course need to be able to drain the exhaust water trap as well. Mine (Vetus) has a drain point on it.

To be fair I think there was some initial confusion as to what system the Good Lady had ie raw water or freshwater.

 

[colhel]

PS - not a "good man" - I am a "good lady"

Many apologies .

 

[Plevier]

To be fair I think there was some initial confusion as to what system the Good Lady had ie raw water or freshwater.

Query addressed not to OP but to several responders specifically talking about freshwater cooled engines.

 

[JokersWild]

Update

Bit of a late addition to this thread, but I thought I'd update with what route the professional took who did this with my "supervision" You never know, someone might look back on this in a year's time with the same question!

The chosen route was to flush the raw-water side through with anti-freeze, pouring it directly into the strainer and running the engine. Definitely needs two of you, but I'd confidently do it without professional help next year.