Radiator cleaner

[Richardtr3a]

I have just descaled the new kettle which we have only had for 3 months. You could see limescale all over the lower half. This is after such a short time.

 

My radiator has had hard water in it for over ten years. I am thinking of using the same product. Is there a special radiator chemical. I am also considering using ionised water for the refill. I use it for the battery and wonder if it would help reduce limescale in the engine, heater etc.

 

Thanks for any advice.

 

Richard & H

[RogerH]

Hi Richard,

the lime scale is a product of the boiling process. You shouldn't get lime scale simply by have hot water (80C) with a fixed volume.

 

Rad flush or one of the wonderfully nasty Fernox products will help flush the system.

 

Soft water, rain water or battery (de-ionised) water will work fine.

 

Don't forget the anit freeze.

 

Roger

[lynchpin]

Hi

Scale is only formed when water is heated over a temperature which I have long since forgotten from my gas fitting apprentice days but very near boiling point, the chalk in the water is released as limescale each time new water is introduced and heated, so unless a car is constantly boiling its water and being topped up only a small amount will be released, so the rad shouldn"t be scaling up.

 

Phil...

[McMuttley]

So how come the outside of my chrome shower dial and pipes are covered in the stuff

[RogerH]

Hi Austin,

because you are using new water all the time there is a lot of potential lime scale available.

 

Even if not boiled it can leach out and stick to its surroundings.

 

A car rad/engine has a fixed amount of water so even if boiled would cause little problem

 

Roger

[ctc77965o]

I have had success cleaning rads with coca cola (Tesco own brand) followed by vinegar. I placed the rad over a pan of boiling water to heat the coke and after half an hour the insides of the rad looked shiny like New.

[John Morrison]

Caustic Soda Solution,

 

be careful, and read the insructions, and on a used cooling system

I would use a mild to medium solution.

 

John

[Rodbr]

WARNING WARNING!

 

Please be extremely careful using Caustic Soda in any concentration. This is particularly the case where there is any potential for blow back. My long term plumber friend was not just blinded but lost the eye completely and a lot of soft tissue damage. Goggles and a full face guard, heavy rubber gloves or gauntlets are the order of the day when using. If anyone should have known the dangers my mate should. DO NOT BE complacent when using caustic please!!!!!!!!!!

[RogerH]

Hi Dave,

cola has a small amount of phosphoric acid in it, so that is probably what is attacking the rusty residue in a rad.

Using any of the rust removers that contain Phosy acid would work - possibly quicker/better.

 

Roger

[McMuttley]

I have had success cleaning rads with coca cola .........

 

I bet it runs sweet after that

[john.r.davies]

Richard,

Your kettle's fur comes from "ionised" water, hard water with calcium etc. ions in it

You want "DE-ionised" water (aka distilled).

 

And anyway, the gunk in a radiator isn't kettle fur, it's the product of corrosion in the system, esp. 'black rust', Fe3O4, that occurs when there is little oxygen available, as there is in a closed engine cooling system. Phosphoric acid, in Coke or as itself, may be the worst possible radiator cleaner, as it reacts with iron oxides to make iron phosphate, one of the few insoluble organic oxides of iron. That makes it useful when preparing a rusty panel for painting, but inside a radiator you want something that will wash out! Vinegar, if you must, produces soluble iron acetate, but why not invest in a proper radiator cleaner if you are concerned. And always add a corrosion inhibitor to your de-ionised water.

 

John

Oh, PS. Corrosion inhibitors act by adding a compound that soaks up all the oxygen in the water.

It does so by being highly ionised!

[AlanT]

I think the stuff blocking your radiator will be iron oxide particulates aggregated by either oily residue or maybe some gluey stuff from degraded ethylene gylcol.

 

There may be a bit of limescale if you filled a lot with hard water.

 

Both of these will break up with phosphoric acid derusting stuff. This wont eat any steel or copper.

 

Shake some stuff out and try a bit and if you get fizzing then you are on a winner.

 

Caustic may work but phosphoric is much safer.

I only use caustic on alloy parts which fizz up quickly and come out really clean.

[Alec Pringle]

Milkstone Remover will shift both limescale and rust, £12-15 for a gallon from your local agricultural supplies shop (it's for use in milking and dairy equipment) - and that's sufficient to clean out your radiator and engine, and leave enough over for an awful lot of parts derusting . . . . . or several more rads and engines !

 

more detail here - http://www.kilco.co.uk/product/circulation-and-bulk-tank-cleaners/milkstone-remover

 

Cheers

 

Alec

[john.r.davies]

Clearly my point about Iron phosphate, the product of iron oxides and phosphoric acid, fell on deaf ears.

Not one but two gurus have since recommended that acid.

Iron phosphate is insoluble; almost any other organic acid will do better in getting the residue out by dissolving it.

 

John

[AlanT]

The precipitate that forms is very fine particles.

 

There is a lot of agitation produced by the release of gas.

A kind of milky liquid will run out.

 

We like phosphoric because we know it won't take any metal off.

Edited December 18, 2014 by AlanT

[Rodbr]

Why not give it the same stuff they give before a Colonoscopy as it seems to clear everything I ate since I was five. A clean colon is a happy colon.

 

Rod

[Lebro]

That's put me right off my sausages

[marki]

Hi All

I used central heating flushing agent as in Fernox, kept it in for a couple of hundred miles a couple of flushes with clean water and all seems well. It's not caustic and vegetable based so no nasties.

Cheers Mark

[Alec Pringle]

Hi John,

 

chemistry never was my strong subject !

 

I work on the basis of the evidence of the Mk1 eyeball, which is that as Alan observes a very cloudy liquid comes out . . . . then flushing and backflushing then shifts a whole lot more crud, in presumably very fine particle form . . . .

 

Cheers

 

Alec

[AlanT]

I have used Phosphoric acid based de-rusters for many different kinds of jobs.

They have some kind of inhibitor which prevents precipitation.

 

This gets used up and then you get the white deposits.

The stronger, that is the less you dilute it, the less likely you are to get precipitate.

 

Only one warning. If you use it on spring steel its likely the spring will crack.

Presumably you cut back a tiny amount and leave a sharp edge to raise the stress.

[john.r.davies]

Fernox "vegetable based"? Hmmm, do you mean "organic"?

Safety Data Sheet lists different contents for different countries.

http://www.fernox.com/files/safetydatasheets/english/57843_central_heating_protector_f1_eng.pdf

 

In the UK it contains:

disodium molybdate

benzotriazole

2,2'-iminodiethanol

propane-1,2-diol

First three are corrosion inhibitors, last is an antifreeze

 

Preston's contents are also listed in an SDS:

Ethylene Glycol

Diethylene Glycol

2-Ethyl Hexanoic Acid, Sodium Salt

Neodecanoic Acid, Sodium Salt

antifreezes and organic acids, maybe to react with iron oxides etc. to produce soluble salts.

Blocked radiator tubes present a very small cross sectional area, so only a small part of a blockage may be affected by a flushing agent. If that agent produces insoluble products, then there is no hope of the blockage being removed! The rest of the blockages hides behind the insoluble barrier. And solid particulate products may worsen partial blockages.

That's why I say, don't use phosphoric acid.

John

[Dave Smith]

I think the point of Fernoc is that it is non toxic as it contains propylene glycol which is alot safer product than ethylene glycol.

Some classic car owners use Fernox Alphi 11 as an antifreeze but I think it does not contain any anti corrosion inhibitors. I seen references to it in RR club articles and also Rover Owners Club.

 

There is currently no car anti freeze available with propylene gylcol in the UK.

 

PS Propylene Glycol is the common name for propane-1,2-diol.

 

Dave

 

Not a Chemist but my Dad was.

[Guest ntc]

If you have a friendly plumber he could power flush it complete with magnets.

[McMuttley]

"friendly plumber" - never met one of those !

[Richardtr3a]

I have been working on this flushing problem. Holts make a 2 pack system, This involves heating up the engine for 40 minutes and then flushing with cold water twice. Is there any potential damage to the engine from introducing cold tap water into a hot engine?

 

It sound as if it may be a safe option. I will call Holts in the morning and need some help on what technical questions to ask.

 

Thanks,

 

Richard