Does antifreeze age?

[raymondh]

After reading the posts on adding Ankersol to extend the life of antifreeze and purchasing some for my heating system as its a pain to drain and refill - so mutch so that I have never done it since the boat was built in 2007

 

When adding the Ankersol I drained a litre from the header tank and kept this fpr topping up

I decided to test the anti- freezing and corrosion prevention of the solution both before and after adding the Ankersol

 

The anti freeze properties are simple, place in the freezer over night and for the corrosion place samples of the system metals in the solution and wait

 

Result of the pre Ankersol freeze test at -18 c no sign of freezing! see pic

 

Other tests in progress and will report back (no sign of corrosion in the pre Ankersol test yet)

 

But - 18C at 7years old food for thougt

 

Ray

Edited November 13, 2014 by raymondh

[b0atman]

You can buy a test Hydrometer for antifreeze.

Surely for boat heating systems long life is to be expected ?

Now engine antifreeze could be a different matter or maybe not !

[FidoDido]

its not the ethylene glycol in antifreeze that ages. its the rust inhibitors. In a domestic radiator system, you are supposed to top up the rust inhibitors every 7-10 years. No doubt you could do the same in a boat - just add some more commercial rust inhibitor bought at Jewsosns, Travis Perkins etc..

[b0atman]

In a domestic radiator system any losses are made up by water from the header tank ball valve .

On most boats these losses are made up by the addition of more premixed antifreeze solution.

[MtB]

its not the ethylene glycol in antifreeze that ages. its the rust inhibitors. In a domestic radiator system, you are supposed to top up the rust inhibitors every 7-10 years. No doubt you could do the same in a boat - just add some more commercial rust inhibitor bought at Jewsosns, Travis Perkins etc..

 

 

News to me. One lives and learns!

 

And you clearly haven't seen the test samples on display at the Kamco labs. The only inhibitors that truly work out of about 12 are Fernox, Sentinel and Kamco (unsurprisingly) as they are all three times the price of the 'own brand' products you recommend.

 

 

MtB

[David Schweizer]

its not the ethylene glycol in antifreeze that ages. its the rust inhibitors. In a domestic radiator system, you are supposed to top up the rust inhibitors every 7-10 years. No doubt you could do the same in a boat - just add some more commercial rust inhibitor bought at Jewsosns, Travis Perkins etc..

 

I have recently done quite a bit of reading up about the life expectancy of Antifreeze, and there seem to be a range of "opinions", regarding it's longevity. There seems to be general agreement that the rust inhibitors degrade over the years, which is why products like Ankersol exist, but views about its long term ability to prevent freezing range from "it doesn't loose it's effect" to it gradually tuns into acid and promotes rust.

 

Last time I was on the boat I tested the antifreeze and it was safe down to at least -15 degrees Centigrade, equating to something like a 25% mix. which is close to the original mix added some eight years ago. This would support the view that it does not degrade very much, and is why I have purchased some Ankersol, although I also plan to add some antifreeze concentrate as well to increase the protection.

[Guest]

 

 

News to me. One lives and learns!

 

And you clearly haven't seen the test samples on display at the Kamco labs. The only inhibitors that truly work out of about 12 are Fernox, Sentinel and Kamco (unsurprisingly) as they are all three times the price of the 'own brand' products you recommend.

 

 

MtB

To be fair, the poster did say "bought at Jewsons" etc, and not specifically "Jewson's own brand."

I believe Jewsons still sell Fernox, or a least they once did. No experience of Travis Perkins.

Edited November 13, 2014 by Guest

[Kwacker]

An Austrian "82" goes down very nicely with fish so I'm told.

[nebulae]

Generaly,the life span of car antifreeze depends on the spec. Blue will give corrosion protection for two years,Red for five years,In my experience,the antifreeze properties last considerably longer. Red costs more than Blue,as you would expect. Cant see any problem with using Fernox in a keel cooled system.You would then have to add a compatible antifreeze.

[DHutch]

I understand Tom (my granddad) changed the anti freeze in the radiators when the boat was five years old, that was 18 years ago, no issues yet although other items have frozen.

 

They may be rotting from the inside however. Time will tell...

 

 

Daniel

[cuthound]

Glycol ethylene does not age. I have direct experience of commercial wet chilling systems that had not had the water/glycol mixture changed in 30 years.

 

As others have said it is the anti-corrosion properties that expire with time. In a heating or chilling system they can be "topped up", but in the cooling system of an internal combustion engine the antifreeze becomes contaminated with combustion byproducts, and thus needs to be changed periodically.

[blackrose]

As others have said it is the anti-corrosion properties that expire with time. In a heating or chilling system they can be "topped up", but in the cooling system of an internal combustion engine the antifreeze becomes contaminated with combustion byproducts, and thus needs to be changed periodically.

 

Yes, when talking about the longevity or life-span of a product, then one needs to consider its functions and properties and in this case it's the ant-corrosive properties of the antifreeze which determine it's longevity, rather than the anti-freeze properties. This is important where you have engines comprising mixed metals in contact such as aluminium and steel to prevent galvanic corrosion.

 

However, on your second point, in a canal boat with a closed loop cooling system (skin tank cooled rather than raw water/wet exhaust), I can't work out where the antifreeze comes into contact with combustion by-products? Isn't it completely separated from the cylinders, and exhaust system? My knowledge of engines isn't what it should be so I may be wrong.

[cuthound]

It shouldn't, but can in the case of head gasket leakage.

 

I suspect that the anti-corrosion properties are sacrificial in a typical multi-metal engine, hence requiring repacing once expended.

[blackrose]

It shouldn't, but can in the case of head gasket leakage.

 

Well, your previous post made it sound like antifreeze would always become contaminated as a matter of course. The point is that head gasket leakage is a separate issue and doesn't really have anything to with required periodic antifreeze changes that you mentioned.

 

Anyway, in the case of head gasket leakage you'd probably have engine oil in the cooling system and vice versa, so the by-products of combustion would be the least of your contamination problems.

Edited November 15, 2014 by blackrose

[Albion]

 

Well, your previous post made it sound like antifreeze would always become contaminated as a matter of course. The point is that head gasket leakage is a separate issue and doesn't really have anything to with required periodic antifreeze changes that you mentioned.

 

Anyway, in the case of head gasket leakage you'd probably have engine oil in the cooling system and vice versa, so the by-products of combustion would be the least of your contamination problems.

That is a common misconception I'm afraid. You are more likely to have combustion gas contamination of the coolant than oil in water or water in oil (the gas pressure causing overflowing of header tanks, gas bubbles in the coolant etc.). That's why, in the trade, you have chemical tests for combustion byproduct that you use on a sample of coolant. Head gasket leakage would have to be confined to coolant/oil gallery interface solely to give the symptoms you describe and yet combustion chamber to coolant is much more likely given the combustion pressures involved.

Roger

[raymondh]

Hi,

just removed from the freezer -18C the seven year old antifreeze solution treated with two weeks ago with Ankersol

Its still fine with no sign of freezing

 

The samples with a mix of metal parts to test the anti corrosion properties of both the Ankersol treated and untreated solutions will take some time to give any meaningfull results ? weeks/months/years?

 

There is no sign of any corrosion to the sample parts as yet - not a high tech test but a bit of fun with real world results

 

Regards Ray

[David Schweizer]

That is a common misconception I'm afraid. You are more likely to have combustion gas contamination of the coolant than oil in water or water in oil (the gas pressure causing overflowing of header tanks, gas bubbles in the coolant etc.). That's why, in the trade, you have chemical tests for combustion byproduct that you use on a sample of coolant. Head gasket leakage would have to be confined to coolant/oil gallery interface solely to give the symptoms you describe and yet combustion chamber to coolant is much more likely given the combustion pressures involved.

Roger

 

This is all very interesting, but could someone pease explain how combustion fumes can get into the coolant, except where there is a failed or failing head gasket.

[Guest]

 

This is all very interesting, but could someone pease explain how combustion fumes can get into the coolant, except where there is a failed or failing head gasket.

A pure guess, and I await being slaughtered, but I would have though a slight weep on the exhaust manifold/heat exchanger gasket/interface could allow coolant contamination?

Porous castings maybe?

 

edited to try and make more sense

Edited November 15, 2014 by Guest

[Albion]

 

This is all very interesting, but could someone pease explain how combustion fumes can get into the coolant, except where there is a failed or failing head gasket.

It can't, except in the specific case that you state. That relies on combustion pressures overcoming coolant system pressure and hence forcing combustion gas into the coolant system.

Roger