Diluting Coolant

[Irish Rover]

Apart from the cost of it are there any advantages/disadvantages to diluting coolant? The water around here is very hard and sourcing distilled water will probably cost as much as the full strength coolant. Will full concentrate coolant provide better anti corrosion protection.?

 

[pvb]

I suppose it depends on which coolant you're using, but you should follow the maker's instructions. Concentrated coolant should be diluted in accordance with the instructions for optimum cooling efficiency. Although you'll probably be instructed to use distilled or deionised water, the tiny amount of minerals in ordinary tap water probably won't make a massive difference.

 

[vyv_cox]

Deionised water is very cheap. Not long ago I bought 5 litres of it in Greece for €1 simply because I needed the bottle, and threw the water away.

 

[thinwater]

I suppose it depends on which coolant you're using, but you should follow the maker's instructions. Concentrated coolant should be diluted in accordance with the instructions for optimum cooling efficiency. Although you'll probably be instructed to use distilled or deionised water, the tiny amount of minerals in ordinary tap water probably won't make a massive difference.

Yes, actually, they will. The OP said his water was very hard. [40 years in the AF manufacturing and testing industry]

No, concentrate will not improve performance. In fact, without at least 35% water it may not circulate properly. Finally, the minimum freeze point is at about 30% water (not concentrate).

Corrosion protection will suffer with water >70%.

 

[RichardS]

As PVB says, the heat transfer properties of neat coolant are not as good as 50:50 coolant so you would be better off diluting it. The freezing point of neat coolant will also be higher but that would not be an issue in the UK.

If you have, or know anyone with a recirculating tumble drier you should quickly be able to get enough water to dilute the antifreeze. This would be much better than using very hard water. I use water from home which has been through the water softener but it sounds as if you don't use one.

Richard

 

[Irish Rover]

The brand I bought is a Turkish brand called Polisan as kindly recommended by another forumite based in Turkey. He mixes 50/50 which according to the instructions provides cover down to -40C. Where I am it rarely gets down to 0C - a few times in the 15 years I've been here - and I doubt even then the engine compartment of the boat sitting in the marina would get anywhere near 0C. The instructions say 15% coolant protects to -6C. So what concentrate should I use for best anti-corrosion and cooling?

 

[RichardS]

The brand I bought is a Turkish brand called Polisan as kindly recommended by another forumite based in Turkey. He mixes 50/50 which according to the instructions provides cover down to -40C. Where I am it rarely gets down to 0C - a few times in the 15 years I've been here - and I doubt even then the engine compartment of the boat sitting in the marina would get anywhere near 0C. The instructions say 15% coolant protects to -6C. So what concentrate should I use for best anti-corrosion and cooling?

50:50 is the optimum for most brands but it should say on the label.

Richard

 

[Irish Rover]

Thanks. 50/50 it is then. Thanks all.

 

[thinwater]

NEVER use water from a softener!

The softener adds chloride ions, which are deadly to engine coolants (spec is 25 ppm). Only DI or distilled water, same as a battery (the specs are actually quite similar). If you have, consider having the coolant tested for chloride.

This is a hot button among AF vendors. Many specifically warn against it.

 

[RichardS]

NEVER use water from a softener!

The softener adds chloride ions, which are deadly to engine coolants (spec is 25 ppm). Only DI or distilled water, same as a battery (the specs are actually quite similar). If you have, consider having the coolant tested for chloride.

This is a hot button among AF vendors. Many specifically warn against it.

We've been through this nonsense many times before.

In essence: calcium/magnesium carbonate + sodium chloride = calcium/magnesium chloride + sodium carbonate

Now, which compound from the right hand side of the equation do you think ends up in the household water supply?

Richard

 

[thinwater]

We've been through this nonsense many times before.

In essence: calcium/magnesium carbonate + sodium chloride = calcium/magnesium chloride + sodium carbonate

Now, which compound from the right hand side of the equation do you think ends up in the household water supply?

Richard

We're not talking mixed bed and we are not talking about chemical reactions. The resin will remove the Mg and Ca. Chloride and carbonate BOTH pass through. The other problem is that the chloride and nitrate content of coastal and well waters is often too high for coolant, and softening will not reduce that.

The standard calls for TDS <50 ppm. Very little tap or softened water is close to that. This is from the US and UK standard (they are the same, from the same committee).

TDS 50 ppm
Chloride 25 ppm
Sulfate 50 ppm
Sulfate

 

[CAPTAIN FANTASTIC]

Some people use deionised water for engine cooling water; the problem with deionised water is that the water lacks ions and it will strip off ions from anything metalic; in some cases it may cause corrosion.

 

[RichardS]

We're not talking mixed bed and we are not talking about chemical reactions. The resin will remove the Mg and Ca. Chloride and carbonate BOTH pass through. The other problem is that the chloride and nitrate content of coastal and well waters is often too high for coolant, and softening will not reduce that.

The standard calls for TDS <50 ppm. Very little tap or softened water is close to that. This is from the US and UK standard (they are the same, from the same committee).

TDS 50 ppm
Chloride 25 ppm
Sulfate 50 ppm
Sulfate

I know exactly what we are talking about .... which is why I said "in essence". Household water softeners use an cat-ion exchange process with the resin holding sodium ions from the sodium chloride regeneration process. The hard water obtains its hardness from the calcium and magnesium ions in the calcium and magnesium carbonate dissolved in the water. This percolates through the resin which exchanges the calcium and magnesium ions for sodium ions which are dissolved in the soft water in the form of sodium carbonate. "Chloride ions passing through" is a total misunderstanding of the ion exchange process I'm afraid.

It seems that I have to go through this explanation every time this "chloride in soft water" fallacy is mentioned. Perhaps it should be a "sticky".

Richard

 

[RichardS]

Some people use deionised water for engine cooling water; the problem with deionised water is that the water lacks ions and it will strip off ions from anything metalic; in some cases it may cause corrosion.

I'm afraid that this is also a total fallacy. De-ionised water is simply water which contains hydrogen and oxygen and nothing else. It will not "strip ions" off anything unless that anything is soluble in water .... in which case any kind of water will dissolve it exactly the same unless the concentration of dissolved ions is so high that the water is saturated .... but, by then, it's hardly water at all.

Richard

 

[thinwater]

I know exactly what we are talking about .... which is why I said "in essence". Household water softeners use an cat-ion exchange process with the resin holding sodium ions from the sodium chloride regeneration process. The hard water obtains its hardness from the calcium and magnesium ions in the calcium and magnesium carbonate dissolved in the water. This percolates through the resin which exchanges the calcium and magnesium ions for sodium ions which are dissolved in the soft water in the form of sodium carbonate. "Chloride ions passing through" is a total misunderstanding of the ion exchange process I'm afraid.

It seems that I have to go through this explanation every time this "chloride in soft water" fallacy is mentioned. Perhaps it should be a "sticky".

Richard

You didn't explain how anions are captured in a cation bed. I have designed both cat ion and mixed bed systems and understand perfectly well.

 

[thinwater]

Some people use deionised water for engine cooling water; the problem with deionised water is that the water lacks ions and it will strip off ions from anything metalic; in some cases it may cause corrosion.

I hope it is obvious that the coolant manufacturers have considered this. In fact, Di water is preferred by the manufacturers, and it is what they use in their manufacturing processes. Ask them. The additive package is complete and is tested using DI water.

 

[pvb]

I hope it is obvious that the coolant manufacturers have considered this. In fact, Di water is preferred by the manufacturers, and it is what they use in their manufacturing processes. Ask them. The additive package is complete and is tested using DI water.

OK, I'm sure manufacturers will prefer that deionised water is used, but in the real world, when motorists (for example) dilute concentrated coolant for their cars, what do they dilute it with? Answer: tap water. And there's no apparent problem resulting from this. So there's no real reason why a boat engine need be treated any differently.

 

[VicS]

I know exactly what we are talking about .... which is why I said "in essence". Household water softeners use an cat-ion exchange process with the resin holding sodium ions from the sodium chloride regeneration process. The hard water obtains its hardness from the calcium and magnesium ions in the calcium and magnesium carbonate dissolved in the water. This percolates through the resin which exchanges the calcium and magnesium ions for sodium ions which are dissolved in the soft water in the form of sodium carbonate. "Chloride ions passing through" is a total misunderstanding of the ion exchange process I'm afraid.

It seems that I have to go through this explanation every time this "chloride in soft water" fallacy is mentioned. Perhaps it should be a "sticky".

Richard

But they do !

Chloride, sulphate, and other anions pass through the cation exchange resin bed unaffected.

 

[thinwater]

OK, I'm sure manufacturers will prefer that deionised water is used, but in the real world, when motorists (for example) dilute concentrated coolant for their cars, what do they dilute it with? Answer: tap water. And there's no apparent problem resulting from this. So there's no real reason why a boat engine need be treated any differently.

They sell distilled water. Do you put tap water in the batteries? I doubt it. Same specifications.

Yes, there are problems, just as there are with batteries. Google the specs. It didn't make it up.

 

[RichardS]

But they do !

Chloride, sulphate, and other anions pass through the cation exchange resin bed unaffected.

Of course, chloride ions already in the water supply do pass through the resin but that's not what is under discussion because if that were a problem then Thinwater would not be saying "NEVER us water from a softener" in reply to my post recommending softener water .... he would be saying "NEVER use tap water" as both naturally hard and naturally soft water contain chloride ions.

The problem with these discussions is that unless a type a 3-page analysis describing exactly how water-softeners work, there are always going to be missing details which someone will pick up on.

I'm surprised that no-one has yet picked up on my "water which contains hydrogen and oxygen" phrase as that is not technically correct but if I explained how the de-ionisation process works then that would be another 3-page analysis. :ambivalence:

Richard