Anti freeze...does it age when unused, just stored????

[jondude]

Was about to change the coolant on my S1, friend says he has the original Unipart stuff, mixed with distilled water but unused...so it has been standing in his garage ( airtight containers ) for a few years.

This made me wonder if anti freeze only loses its corrosion inhibitors if it is indeed being used to fight corrosion and met with corrosion - that is, moving around and flushing through pipes at cold and hot temperatures?

Any one got chemistry 'O' level or just know??

( I would also presume most garages work this way - put in unused by quite old coolant at service time )

[21TonyK]

It must lose some of it's "properties" else they wouldn't seal it with a foil cap and (I assume) you wouldn't need to replace it every year or so.

[jondude]

Yep, do agree....but untouched anti-freeze ( mixed with distilled water ) is not actually using any corrosion inhibitors, or being attacked by rust.

I suppose it is the same theory I have here as unused oil which is years old. As it has not been in an engine and fighting heat and carbon, it must ( should?? ) still be fine to use.

Maybe

[Paul RN]

It probably settles to some degree like most liquids after time.

[teepee]

I have chemistry O level (& A level!!). Could the reason for the foil be that in antifreeze there are some chemicals that would evapourate in an open container? eg alcohols. OR the foil is tamper indicator i,.e the bottle has been opened by some toe rag and the antifreeze stolen & replaced with cat urine? Either way using prediluted anti freeze, as long as its been stored in an airtight container is surely OK. Afterall the chemicals haven't had anything to do, much like an open can of oil is safe to use. sounds logical to me, but it's not my engine....

[mike_knott]

I would expect it to be ok otherwise there would be a use by date on it.

Give it a good shake first just in case anything has settled out.

Mike...

[noodleman]

Have a look at a bottle in a garage. If it doesn't say so on the bottle, it'll be fine.