Safe Rydlyme Alternative?

Rydlyme works well but is expensive.
Any comments why an aluminium cooling system flush such as made by Prestone would not be equally effective? It's half the price.

Interesting read:
Descaling Solutions for Boats - Practical Sailor
Interesting but as far as I can see the Prestone flush contains Citric acid which does not feature as an ingredient in the Practical Sailor test. The ProFlush as used by Mr Googler contains phosphoric acid (although they do say at what concentration) which is the base ingredient of the two top rated in the Practical Sailor test.

www.solocoastalsailing.co.uk
 
Have used Barnycule Buster from Ebay in the dim and distant past.
In extreme case on Perkins Sabre removed the heater changer cooling tube stack (simple quick job) and soaked in brick cleaner.
Have seen some impressive results by somebody who used Rydlyme and pumped it round a 63P.
Unclogged almost completely blocked heat exchanger to bright shiny and clear in about 3/4 hours.
 
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Mightn’t the phosphoric acid act as a rust inhibitor? Not sure about aluminium but it did a mean job on our iron keel!
 
I have found the B&Q Plumbers descaler powder to be quite effective and not so nasty to use. It can be bought from Ebay as Sulphamic Acid, and comes in bags that look like bags of Cocaine - not sure I would snort it though !

Last time I had to descale was on the Cummins seawater / freshwater shell & tube coolers on my last boat, where I used to leave this stuff in for 24 hours and return to completely clean coolers. I always made a point of removing the zincs whilst the soak was in progress.
 
The issue is any acid micro etching the internal surfaces .Some acids will attack different metals greater than others .
Manufactures recommendations are bast adhered to .
The manufacturers tech if you buy his time and there parts ( various gaskets ) will use an acid no doubt back at the workshop to soak the stacks in .Q is which acid are they bathed in overnight ?

Ridlime seems to be etch friendly suitable on all even the most delicate metals and there solder concoctions in there stacks .
Blurb says it’s got various trade mark buffers that resist this micro etching .
Its been tried and tested by all with no adverse effects .
I have used it on my MAN s and that was the reason why .
I think it was worth the premium price for piece of mind as no adverse effects noted to date .

The issue with preventing micro etching is as well of dissolving the calcium based scale the other acids like brick cleaner or a unspecified concentration of “ white powder “ mixed with water diy - theses acids leave a none factory rough surface on the tubes. Which then accelerate re calcification of critters + crud etc .So you are hooked .The tubes loose there factory smoothness .
There is significant chatter of solder joints being attacked too along with any weak aluminium pipes around the engine , ex coolers .

Additionally out side of this thread but the smarter guys will see the logic ( there are a few on here ) any internal clean be it ridlyme or other none buffers acids will only clean the internal surfaces of the coolers .

This might be all that’s needed, the internal clean up .

How ever consider the charge air cooler ( CAC ) air fins on some. engine marques where by oil from the crank or other ventilation system has deposited a oily layer .This oily layer can reduce the efficiency of air cooling as much as crud on the sea water side .
Unless you have CAC temp gauges you will never know .
Similarly the main cooler close cooling side can develop a smear from old stale aged coolant .Not as bad is the oily layer on the CAC but enough to shove the jacket temp up a couple of degrees .

Thats the manufacturers rationale behind a full strips……it cleans both sides + fresh gaskets and rubbers , new fastenings ( less censure risk going Fwds ) and fresh timely coolant change .
Finally your coolant has additives to resist corrosion which diminish over time anyhow .
They say refresh every 3 years .But do check with your manufacturer .
Remember the engines are sat pickling in this 24/7 / 356 .surrounded by a salty environment.
 
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The issue is any acid micro etching the internal surfaces .Some acids will attack different metals greater than others .
Manufactures recommendations are bast adhered to .
The manufacturers tech if you buy his time and there parts ( various gaskets ) will use an acid no doubt back at the workshop to soak the stacks in .Q is which acid are they bathed in overnight ?

Ridlime seems to be etch friendly suitable on all even the most delicate metals and there solder concoctions in there stacks .
Blurb says it’s got various trade mark buffers that resist this micro etching .
Its been tried and tested by all with no adverse effects .
I have used it on my MAN s and that was the reason why .
I think it was worth the premium price for piece of mind as no adverse effects noted to date .

The issue with preventing micro etching is as well of dissolving the calcium based scale the other acids like brick cleaner or a unspecified concentration of “ white powder “ mixed with water diy - theses acids leave a none factory rough surface on the tubes. Which then accelerate re calcification of critters + crud etc .So you are hooked .The tubes loose there factory smoothness .
There is significant chatter of solder joints being attacked too along with any weak aluminium pipes around the engine , ex coolers .

Additionally out side of this thread but the smarter guys will see the logic ( there are a few on here ) any internal clean be it ridlyme or other none buffers acids will only clean the internal surfaces of the coolers .

This might be all that’s needed, the internal clean up .

How ever consider the charge air cooler ( CAC ) air fins on some. engine marques where by oil from the crank or other ventilation system has deposited a oily layer .This oily layer can reduce the efficiency of air cooling as much as crud on the sea water side .
Unless you have CAC temp gauges you will never know .
Similarly the main cooler close cooling side can develop a smear from old stale aged coolant .Not as bad is the oily layer on the CAC but enough to shove the jacket temp up a couple of degrees .

Thats the manufacturers rationale behind a full strips……it cleans both sides + fresh gaskets and rubbers , new fastenings ( less censure risk going Fwds ) and fresh timely coolant change .
Finally your coolant has additives to resist corrosion which diminish over time anyhow .
They say refresh every 3 years .But do check with your manufacturer .
Remember the engines are sat pickling in this 24/7 / 356 .surrounded by a salty environment.

too many words
 
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Briefly…! I reckon the phosphoric might help prevent the etching. Otherwise, why is it an ingredient in central heating descaler (citric acid and phosphoric acid)? It is true that the acid itself causes ‘corrosion’ of sorts, as I understand ‘etching’.
 
Briefly…! I reckon the phosphoric might help prevent the etching. Otherwise, why is it an ingredient in central heating descaler (citric acid and phosphoric acid)? It is true that the acid itself causes ‘corrosion’ of sorts, as I understand ‘etching’.
Briefly, you don’t run seawater through your central heating .

Etching the acids starts to pull lumps out of the what was smooth metal surface.This rough surface re calcifies , crud’s up faster than the factory finish smooth . Nowt to do with corrosion.
 
I went with Rydlyme in the end but would have gone with MrGooglers suggestion if I had a local Force4 to collect it from. If paying postage there wasn't much saving going with Proflush.

It worked exactly as expected. I removed the anodes and thermostat, it was brutal to the limescale and very kind to an old zinc I placed in the solution.

Before the Rydlyme, I tried Wynn's coolant flush only because I had some. It claims to remove scale but it was a joke and no wonder because afterward I read the blurb and it's an acid free cleaner.
 
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