Calling all Chemical scientists....

[Mr Cerbera]

As I was doing the shopping the other day I noticed a cleaning liquid that was a vinegar-based product and quoted "anti-calcium/limestone".

Do you think that it would be
a) genius
b) sensible
c) crazy
to flush my cooling system out with a diluted solution containing some of this ?

Thanks for any thoughts

[Loach1]

I used a product called 'CLR', which stands for 'calcium, lime and rust', to flush out the cooling system on our Passat. I was nervous because the Passat system had plastic, rubber, aluminium and iron, so I poured some on some aluminium foil and left it for a couple of days. It did nothing to the foil at all, but it shifted a ton of junk from the heater core. I flushed the system out with copious amounts of water afterwards, then filled with Pentosin and distilled water.

That was my experience, these products aren't that corrosive it seems. Just let the vinegar break down the minerals and flush thoroughly afterwards, then stay away from tap water.

[Mighty Flex]

It will probably work to a degree. Vinegar will help with the sludge and range of scales that may build up, but is pretty ineffective against rust.

There are plenty of radiator flushes available that will work with out the unknowns - a lot are oxalic acid based. This forms a soluble complex when they react with rust so help to clear this out too (great stuff for removing rust and rusty marks from other things too). Some are alkaline caustic type jobbies, which work in a different way again...

A quick flush with these dilute acids will not harm aluminium, but in theory it will react over time

Some people mention hydrochloric (mutriatic) acid but that will go through aluminium very quickly and isn't any better against rust than oxalic acid. Strong acids are best avoided (regardless of concentration).

There's plenty of info out there, if you stick to sensible tried and tested things you can't go far wrong, provided you make sure you read the instructions / do your research and make sure your cooling system doesn't contain anything incompatible.

Not a brilliant answer - if in doubt don't use it.

Edit: the CLR mentioned above uses lactic acid. It's another weak acid like oxalic acid. I don't think you can go far wrong with things like this, though they may well not be the ideal solution.

Edited by Mighty Flex on Tuesday 4th March 12:08

[Mr Cerbera]

Thanks Gents - just the sort of advice I was hoping for.

In fact, I am quite stunned that the first dozen answers weren't a tirade of abuse.

So, "Thanks !", once again.

[Mark.]

Mr Cerbera said:

In fact, I am quite stunned that the first dozen answers weren't a tirade of abuse.

You are a madman! Go and stand in the corner.

Sorry, no idea on usefulness of product but would hate you to be disappointed with a lack general slagging.

[Mr Cerbera]

Mark. said:

You are a madman! Go and stand in the corner.

Sorry, no idea on usefulness of product but would hate you to be disappointed with a lack general slagging.

Phew, thanks .Mark. For a second I'd thought I'd fallen through a crack in the time/space continuum and ended up in a parallel Universe.
Thank you for restoring my faith in (this) reality.

(plus Whitesnake have just come on the radio )

[Mighty Flex]

Mr Cerbera said:

As I was doing the shopping the other day I noticed a cleaning liquid that was a vinegar-based product and quoted "anti-calcium/limestone".

Do you think that it would be
a) genius
b) sensible
c) crazy
to flush my cooling system out with a diluted solution containing some of this ?

Thanks for any thoughts

I have just noticed this bit. I now have an image of it being used to dissolve unwanted architectural features.

[Superjuiced]

Its about solubility, the more acidic the solution the less likely you will get deposition like calcium, but then the more susceptible you will be to corrosion. Calcium is an inverse soluble mineral, so generally the higher the pH then the amount of calcium that can be held in that solution decreases. the same applies to temperature (its why you get bad scaling in your kettle, and once it forms it provides an ideal site for other stuff to form like iron.

The best way to flush it out would be to use mineral water and just keep changing it really regularly, because it is so pure it will absorb existing deposits in the circuit, but if you have a lot of crap in there you may need to do it quite regularly. I'm not sure what anyone else experience are with ali rads but ive seen some go quite regularly and to me that is a sign that whatever solution people are using is just eating it away from the inside. The problem with de-ionsied water is it is very pure, and will want to absorb what it comes into contact with as pure water is a natural solvent. The best balance would be a mineral water with relatively low hardness and low chlorides. Tap water in most of populated UK is pretty hard and that will just sludge up your system over time.

[Mr Cerbera]

Cheers Paul,

I even understood that !