Removing silt and limescale from radiator

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eddiecross
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#1 Removing silt and limescale from radiator

Post by eddiecross » Sun Jan 03, 2021 12:22 pm

Hi,
S1 4.2 Rad is out and on the bench.
Its old but seems sound.

While it is on the bench Ideally I would like to place it with the inlet/outlet pipes upmost and fill with some kind of descaler and leave for a few days to soak then flush out with water.

Any suggestions of what to use?

Thanks
Eddie


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christopher storey
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#2 Re: Removing silt and limescale from radiator

Post by christopher storey » Sun Jan 03, 2021 12:30 pm

Citric acid , available from pharmacies . Dissolve perhaps 1/2 lb , 0.25lg, in hot water , and leave in for 2 to 3 days . It will turn bright green and will do the job without harming the radiator

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cactusman
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#3 Re: Removing silt and limescale from radiator

Post by cactusman » Sun Jan 03, 2021 1:59 pm

Agreed.. If your chemist does not sell it then it is readily available on line... Certainly don't use a strong mineral acid. And when you refill the system don't use tap water...crazy tip for anyone with a dehumidifier in their garage.....don't throw the water it collects away....store in a clean plastic container as it is ideal for both refilling cooling systems and washer bottles.... :bigrin: :bigrin:
Julian the E-type man
1962 FHC
1966 MGB....fab little car too

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eddiecross
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#4 Re: Removing silt and limescale from radiator

Post by eddiecross » Sun Jan 03, 2021 5:50 pm

Thanks Julian and Chris,
I googled a bit and it seems that vinegar is slightly stronger so may try that 1st.

I have collected about 6 litres so far from my de-humidifier...getting there!

Thx
Eddie

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#5 Re: Removing silt and limescale from radiator

Post by cactusman » Sun Jan 03, 2021 6:30 pm

Yep....wine vinegar will be fine....ethanoic acid....or you can use methanoic acid...sold as kettle and bath descalant under the kilrock brand....I would dilute with warm water....one part kilrock to four parts water....not as cheap as vinegar though!
Julian the E-type man
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eddiecross
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#6 Re: Removing silt and limescale from radiator

Post by eddiecross » Sat Jan 09, 2021 11:37 am

Hi,
Progress so far.
Tipped just under 5 litres of this vinegar neat into the rad.
Been there a couple of days so far but does't seem to be much going on.

Do I just need to be patient?

Eddie
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Thx
Eddie

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mgcjag
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#7 Re: Removing silt and limescale from radiator

Post by mgcjag » Sat Jan 09, 2021 11:52 am

Hi Eddie...i thought that vinegar disolves lead in solder....could be wrong.....why not just take it to a rad refurbisher have it cleaned out properly and pressure tested...also i dont think all vinegars are the same acid......Steve
Steve
1969 S2 2+2 & Building a C type replica

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christopher storey
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#8 Re: Removing silt and limescale from radiator

Post by christopher storey » Sat Jan 09, 2021 12:53 pm

I'll say it again : try citric acid. It has never failed with me

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#9 Re: Removing silt and limescale from radiator

Post by Heuer » Sat Jan 09, 2021 1:21 pm

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£9 for 18 sachets:
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#10 Re: Removing silt and limescale from radiator

Post by cactusman » Sun Jan 10, 2021 8:20 am

According to oust....contains lactic acid.....citric is better......and much cheaper....5 Kilograms will cost around £15 from ebay....
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#11 Re: Removing silt and limescale from radiator

Post by Series1 Stu » Sun Jan 10, 2021 9:28 am

Citric acid is definitely a better descaler than vinegar although both should work.

I can't sing the praises of Kilrock highly enough. I've used it quite extensively lately and find it quick, easy and reliably effective. There's something reassuring about the fizz it produces while going to work on the scale.

Of course, theses things are only effective at removing limescale (acid dissolves alkaline) so don't necessarily expect them to remove solidified sediment and sludge, which is more likely to give you cooling and circulation problems.

Regards
Stuart

If you can't make it work, make it complicated!

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#12 Re: Removing silt and limescale from radiator

Post by cactusman » Sun Jan 10, 2021 9:40 am

Kilrock is good stuff....more.expensive though. Won't significantly affect solder joints or the metal of the rad although a gentle pressure test after a thorough flush might be wise...here a water butt might be handy.
Julian the E-type man
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#13 Re: Removing silt and limescale from radiator

Post by MarekH » Sun Jan 10, 2021 10:23 am

Series1 Stu wrote:
Sun Jan 10, 2021 9:28 am
Of course, theses things are only effective at removing limescale (acid dissolves alkaline) so don't necessarily expect them to remove solidified sediment and sludge, which is more likely to give you cooling and circulation problems.
Not quite. Try "acid+base=salt+water". Acids don't dissolve anything. There is a chemical reaction where both the acid and base decompose and the constituents recombine in a different order. The objective is that the previously unwanted and insoluble base is swapped into some different chemical combination which is soluble.

Series1 Stu wrote:
Sun Jan 10, 2021 9:28 am
There's something reassuring about the fizz it produces while going to work on the scale.
Quite the opposite - it probably means it's acting far too fast and aggressively. I'd go for the most slow and boring substance possible.

kind regards
Marek

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#14 Re: Removing silt and limescale from radiator

Post by Series1 Stu » Sun Jan 10, 2021 11:46 am

MarekH wrote:
Sun Jan 10, 2021 10:23 am

Not quite. Try "acid+base=salt+water". Acids don't dissolve anything. There is a chemical reaction where both the acid and base decompose and the constituents recombine in a different order. The objective is that the previously unwanted and insoluble base is swapped into some different chemical combination which is soluble.
Hi Marek

"Dissolve - become or cause to become incorporated into a liquid so as to form a solution."

I suppose I used lay terms to describe a chemical matter but, to be clear, it is quite correct to say that a descaler will not necessarily remove the sludge and sediment accumulated in a radiator.

Regards
Stuart

If you can't make it work, make it complicated!

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#15 Re: Removing silt and limescale from radiator

Post by Geoff Allam » Sun Jan 10, 2021 7:04 pm

So, after descaling what is recommended for sediment and sludge?
Geoff Allam
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#16 Re: Removing silt and limescale from radiator

Post by mgcjag » Sun Jan 10, 2021 7:15 pm

Dont mess about with diy home remedies...there are plenty of off the shelf radiator cleaners than wont affect the metal or solder that will clean out rust and scale....and be safe for your ali head and rubber hoses.....Steve
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#17 Re: Removing silt and limescale from radiator

Post by cactusman » Sun Jan 10, 2021 8:12 pm

I'd agree...if the radiator is in the car and you are flushing the whole system use a proprietary engine flush....I think Eddie had his radiator on the bench though....
Julian the E-type man
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eddiecross
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#18 Re: Removing silt and limescale from radiator

Post by eddiecross » Sun Jan 10, 2021 10:01 pm

Tipped out the vinegar today- it was a bit cloudy and some sediment came uot too but not a great deal.
I didn't flush it.

From the tops of the cooling matrix I could see, there was still some kind of scale- was soft so maybe it'll flush out.

I have ordered a bottle of Kilrock. Have refilled the rad with the old vinegar and will flush and replace with the Kilrock when it arrives and let you know.

Thanks for the advice so far.

Eddie

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#19 Re: Removing silt and limescale from radiator

Post by mgcjag » Mon Jan 11, 2021 9:51 am

I do find it a bit odd that after all the input on this thread you have refilled with spirit vineger (acetic acid).....which is a corrisive to metal and the lead in the solder....Steve
Steve
1969 S2 2+2 & Building a C type replica

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#20 Re: Removing silt and limescale from radiator

Post by eddiecross » Mon Jan 11, 2021 12:38 pm

Can anyone else confirm that Steve is correct and I am damaging my radiator by filling it with Vinegar?

Thanks
Eddie

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