Anti-freeze addition -advice please

[Ricd]

I have a VP MD2020. I normally winterise the raw water side by disconnecting the hose at sea-cock and putting it into a bucket of 50/50 AF. Its a bind due to location of sea-cock. The raw water filter is much more accessible so can I simply add neat AF via the raw water filter? Are there any problems with using neat AF?

 

[ianat182]

As I understand from previous posts 100% antifreeze is not the answer but 50/50 is; many of the Halfords and other offerings are premixed to the 50/50 proportion already.

ianat182

 

[theoldsalt]

Ricd,

Adding water to pure antifreeze actually reduces it's freezing temperature. That is why we use a 50/50 mix. Pure AF would not adequately protect against very cold weather.

 

[Ricd]

Thanks all for advice...Just to confirm you can add the 50/50 via the raw water filter?

 

[David2452]

That's the way I do it, just make sure you have everything ready.

 

[Ricd]

That's the way I do it, just make sure you have everything ready.

Cheers

 

[Halo]

Statement of the Bl**ding obvious but dont forget to close the inlet sea cock if filling via the raw water strainer. I once wasted a watering can full of antifreeze by this oversight!!

 

[VicS]

Neat undiluted antifreeze is, I understand, detrimental to the water pump impeller, maybe to hoses as well.

For that reason alone do not use it undiluted

Pure ethylene glycol freezes at -12C so although it will give good protection against freezing it is no better than a mixture with a concentration of about 25%.

A 50% solution freezes at about -34 C. The lowest freezing point, below -50C, is obtained with a mixture around 70%

If the freezing point is plotted against % glycol then the result is something like this



Remember also that ethylene glycol is toxic to both mammals and marine life. Any used for winterising should be collected and disposed of safely.

 

[Ricd]

Thanks to all.....diluted it is and I will close the seacock.

Cheers

 

[Plevier]

I have a 2020. The Vetus water trap in the exhaust has a drain point on it. If I open the raw water strainer, open the seacock, drain the raw water pump and drain the water trap, doesn't that clear everything without needing A/F in the raw water system?
I have A/F in the fresh water circuit.

 

[VicS]

I have a 2020. The Vetus water trap in the exhaust has a drain point on it. If I open the raw water strainer, open the seacock, drain the raw water pump and drain the water trap, doesn't that clear everything without needing A/F in the raw water system?
I have A/F in the fresh water circuit.

Do you also have a water cooled gear box? If so blow the water out of that as well.

 

[vyv_cox]

I have a 2020. The Vetus water trap in the exhaust has a drain point on it. If I open the raw water strainer, open the seacock, drain the raw water pump and drain the water trap, doesn't that clear everything without needing A/F in the raw water system?
I have A/F in the fresh water circuit.

Exactly so. I am puzzled that so many people are trying to add antifreeze to the seawater side of an indirectly cooled system. The only justification for this is that the seawater side includes components that corrode, in which case the inhibitor in the antifreeze will prevent it. Is the Volvo heat exchanger made from carbon steel? If not, just drain the seawater, which is undoubtedly the cheapest and most effective way to prevent freezing.

 

[theoldsalt]

Vyv,

Would it not be true to say that some boats have parts of a direct cooling system that cannot be drained (eg exhaust watertrap) that would benefit from AF protection?

 

[vyv_cox]

I guess there may be some traps that don't have a drain trap, although I have yet to come across one. All of them can be drained by removing one or both hoses.

 

[Miker]

I have a Penta MD2010B. I stuff a short length of hose into the outlet side of the raw water filter (the side leading to the engine) and stick the other end into a bucket of 50% antifreeze. A few turns of insulating tape around the hose end ensures an air tight fit with the water filter outlet,

 

[Plevier]

VicS - no my MD2020D does not have a watercooled gearbox; possibly earlier variants did. My 2002 did.

Vyv - the heat exchanger is brass/copper.

So I think with the water trap drained it should be OK.

 

[tidclacy]

Exactly so. I am puzzled that so many people are trying to add antifreeze to the seawater side of an indirectly cooled system. The only justification for this is that the seawater side includes components that corrode, in which case the inhibitor in the antifreeze will prevent it. Is the Volvo heat exchanger made from carbon steel? If not, just drain the seawater, which is undoubtedly the cheapest and most effective way to prevent freezing.

Quite so, surely a flush out with fresh water is the only maintenance item required for the raw water system.

 

[VicS]

VicS - no my MD2020D does not have a watercooled gearbox; possibly earlier variants did. My 2002 did.

Vyv - the heat exchanger is brass/copper.

So I think with the water trap drained it should be OK.

You forced me to check.

Earlier models did have water cooled MS2 gearboxes The OP does not tell us which version of the engine he has !

If he does has an MS2 box then it is something that must be drained if it is not treated with antifreeze.