Questions about anti freeze

Nostrodamus

Nostrodamus

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I want to change the coolant in my engine.
I have seen green, blue, red and pink anti freezes. I know that you should not mix red and green as i believe they are based on different components which wont mix.
Is there one colour or based coolant that is better for boats that others. I noticed most people tend to use green.
On the bottles it usually says that that the anti freeze/coolant can be used direct from the bottle without mixing with water.
We are in the Med so we are not really worried about the water freezing but should you use the product direct from the bottle or is it best to mix it with water and how much water.
Thank you for any replies.
 
Ignore the colour. It used to be that simple but these days different manufacturers are using different colours for the same type of antifreeze.

If you are going to drain out the old antifreeze you are in the best position as you can drain it and run up to temperature and flush a couple of times with plain water to get all the old stuff out. Try and use soft water at all times if you can. I take a 20L polykeg of soft water from home down to the Med for this sole purpose although not everyone can do that, of course.

When you drain out the system each time you will probably find that you cannot get out all the coolant / water. I usually measure the first draining so I have an idea how much gets left behind each time.

When you come to fill the system with the recommended antifreeze - use an OAT coolant if that is approved by the engine manufacturer, usually orange / pink but not always - look up the total volume of coolant including the calorifier. If that is 5 litres say, and you are going to use a 50:50 mix, then start by pouring in 2.5 litres of neat undiluted antifreeze then top up with water, use engine, then recheck.

This ensures that you will end up with a 50:50 mixture even if the calorifier is still full of plain water before you start adding new antifreeze.

Clearly, in the Med, all this has little to do with freezing but is all to do with anti-corrosion.

Richard
 
RichardS. Thank you for the reply.
I will be flushing it through several times.
Not sure what I should do about diluting it or how much. It does say you can use it strait from the bottle or dilute it.
I have one at the moment which is for aluminium which I believe my heat exchanger is.
Before I fill it I am hoping to take the heat exchanger off and clean that first.
Volvo MD22
 
Nostrodamus said:
RichardS. Thank you for the reply.
I will be flushing it through several times.
Not sure what I should do about diluting it or how much. It does say you can use it strait from the bottle or dilute it.
I have one at the moment which is for aluminium which I believe my heat exchanger is.
Before I fill it I am hoping to take the heat exchanger off and clean that first.
Volvo MD22
Click to expand...

For an MD22 I am pretty sure you should use a conventional low silicate type of antifreeze ... as used in older car engines. If a long life, OAT, type is required it will be specified in the owners manual.

Do not mix the two types.

It is normally supplied ready diluted or as a concentrate which is diluted ( usually 33% or 50%) as instructed on the can. Volvo specify distilled/ deionised water if your water hardness or dissolved solids exceed certain figures .......... then it makes sense to buy it ready diluted ( see the manual for details of the water analysis)


Dont pay Volvo prices... a car antifreeze is just the same from Halfords or your favourite car parts shop
 
Last edited:
VicS said:
It is normally supplied ready diluted or as a concentrate which is diluted ( usually 33% or 50%) as instructed on the can. Volvo specify distilled/ deionised water if your water hardness or dissolved solids exceed ceratin figures .......... then it make sense to buy it ready diluted ( see the manual for detials)
Click to expand...

The problem with ready diluted is that if you have a reserve volume which you cannot easily drain, and that can easily be 25% of the total volume on some systems, you will never get to 50:50 as that is the dilution which the purchased fluid is already at.

In such systems, my procedure in #2 is the only sensible way to achieve 50:50 but you must use concerntrated antifreeze and not diluted for my calculated example to make sense.

To Nostro - do not worry about pouring concentrated antifreeze into the system as once you run the engine it quickly becomes distributed.

Richard
 
RichardS said:
The problem with ready diluted is that if you have a reserve volume which you cannot easily drain, and that can easily be 25% of the total volume on some systems, you will never get to 50:50 as that is the dilution which the purchased fluid is already at.

In such systems, my procedure in #2 is the only sensible way to achieve 50:50 but you must use concerntrated antifreeze and not diluted for my calculated example to make sense.


Richard
Click to expand...

But In the Med the Op is probably not unduly worried about having protection down to below -30C. Eve 33% will give protection down to -18C
 
VicS said:
Dunno!
Your link is all in some foreign language........... Is it a conventional low silicate type or an OAT type? ( or even a hybrid type specified by some vehicle manufacturers
Click to expand...

SPECIAL PROTECTIVE RADIATOR DIESEL
READY / -35 ° C + 124 ° C
- PRODUCT DESCRIPTION
The new direct injection diesel engines require a cooling liquid capable of: supporting a better heat dissipating effectively heat in the circuits ever more compact and consequently with less coolant available, provide greater protection from the risk of corrosion using the new organic technology, have a high boiling point for a better
protection.
Special Diesel is the liquid of new generation can ensure that:
Frost protection down to -35 ° C
Protect from high temperatures inside of the cooling circuits of the liquid turns to a pressure that can reach up to 1.8 bar, this pressure the product protects up to + 124 ° C.
Protect the corrosive effects caused galvanic currents, particularly active in new engines with strong presence of electronic components.
Prevent the formation of rust and incrustations even in the presence of hard water, protecting the radiator in time.
- USES
Protective ready for cooling systems,
also suitable for top-up and miscible with any
existing liquid.
- SPECIFICATIONS
Liquid aspect
clear
Color Purple
odor
specific gravity of 1.067 kg / lt
pH t.q. 8.5
freezing point (t.q.) -35 ° C.
diebollizione point (1.8 bar) + 124 ° C
The above data are not specifications and are subject to normal tolerances production
- STORAGE
Unopened and stored at room temperature environment and protected from direct sunlight top
3 years
- PACKAGE
HDPE bottle
Cod. 8018 lt 2
- NOTES
For information on product safety is should consult the MSDS.
 
Nostrodamus said:
SPECIAL PROTECTIVE RADIATOR DIESEL
READY / -35 ° C + 124 ° C
- PRODUCT DESCRIPTION
The new direct injection diesel engines require a cooling liquid capable of: supporting a better heat dissipating effectively heat in the circuits ever more compact and consequently with less coolant available, provide greater protection from the risk of corrosion using the new organic technology, have a high boiling point for a better
protection.
Click to expand...



So it is an OAT type. AFAIK not called for, but possibly Ok for, an MD22. It is copper radiators that it is not compatible with I believe, Modern cars have aluminium radiators

Reference there to cylinder liner cavitation erosion which the OAT formulation is able to prevent......... For this reason it is specified, for example, for many Yanmar engines.


Looks like it is ready diluted .. confirmed by the quoted density and freezing point
 
VicS said:
But In the Med the Op is probably not unduly worried about having protection down to below -30C. Eve 33% will give protection down to -18C
Click to expand...

Agreed ... but as I said in #2, it's corrosion protection that we are looking for and the stronger the concentration within the constraints of good heat dispersion, which would be worse at 100% concentration, the happier I am. In fact, OAT at 50% will easily protect against corrosion for 10 years.

For the same reason I assume, cars in the UK are normally filled at 50% even though -18C at 33% would be more than enough for frost prevention.

At the end of the day, you pays your money and you takes your choice! :encouragement:

Richard
 
Last edited:
RichardS said:
When you come to fill the system with the recommended antifreeze - use an OAT coolant if that is approved by the engine manufacturer, usually orange / pink but not always -
Click to expand...

Longlife OAT is not compatible with many older engines. Standard 2 year IAT blue or green stuff is compatible with all I believe. I stick to that.
Do people put a/f in cars in that area or do they just use inhibitor additives? You could do that.
 
Plevier said:
Longlife OAT is not compatible with many older engines. Standard 2 year IAT blue or green stuff is compatible with all I believe. I stick to that.
Do people put a/f in cars in that area or do they just use inhibitor additives? You could do that.
Click to expand...

THERE are engines where OAT is specified. Many if not most Yanmar engines ITYWF. The reasons being linked to cavitation erosion of cylinder liners

AFAIK the reason OAT is not suitable for older cars is that they have copper radiators .... there may not be any reasons why it is unsuitable for older boat engines.
 
VicS said:
THERE are engines where OAT is specified. Many if not most Yanmar engines ITYWF.

### OK didn't know that. I don't think OAT is a requirement for any VP engines although it is permitted for recent ones.

The reasons being linked to cavitation erosion of cylinder liners
### Why is it helpful for that? (Genuine question - not arguing!)

AFAIK the reason OAT is not suitable for older cars is that they have copper radiators .... there may not be any reasons why it is unsuitable for older boat engines.
### Yes my understanding is the same re copper. Wouldn't it also be unsuitable for brass/bronze heat exchangers in that case?
Click to expand...

.
 
Plevier said:
The reasons being linked to cavitation erosion of cylinder liners
### Why is it helpful for that? (Genuine question - not arguing!)
Click to expand...

Dont know... at least have forgotten the reasons. If you Google for cavitation erosion you should find all that I have forgotten.

AFAIK the reason OAT is not suitable for older cars is that they have copper radiators .... there may not be any reasons why it is unsuitable for older boat engines.
### Yes my understanding is the same re copper. Wouldn't it also be unsuitable for brass/bronze heat exchangers in that case?
Click to expand...

Possibly but the copper matrix in car radiators is paper thin ........ something in the back of my mind says that the soldering may be the problem. Id expect a decent heat exchanger to be hard soldered whereas car rads were just soft soldered.
I look things up but these days can never remember the stuff I've read. :(
 
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