Raw water cooling circuit de-scale advice?

RobWales

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21 Sep 2006
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1,963
Location
Gran Canaria
www.3ksengineering.com
I'm going to attempt to de-scale my AD41 engines over the holidays and was wondering if there is an off the shelf "domestic" product worth trying?
I've read previous posts on here regarding rydlyme but as there are products out there that de-fur your kettle,dishwasher etc I was wondering if they would possibly offer an alternative?
Any other hints tips and advice on this subject would be appreciated as its a job I've not done before.
PS raw pick up is via my 290 dp drives.
Thanks all
Rob
PPS boat is on its marina berth.
 
I have never tried it in AD41's but my Dad has used kettle/iron descaler on perkins engines on his previous boat and it did clean out a lot of gunk. FWIW I have also been told that it works on blocked heater matrixes.
 
Rydlyme you are aware of.

The readily available "domestic" product that should do the trick is Fernox DS-3. It is a sulphamic acid based central heating boiler descaler. Readily available from plumbers merchants and DIY stores (even see it in our local Homebase and if they have it practically every shop in the country will have.)

I am sure there are other brands but it is an acid descaler that you require,

DS-3

Some descalers are based on organic acids which will probably be slower but more environmentally friendly if the effluent is to be discharged into the water. In fact sulphamic acid is classed as dangerous to the environment so that is not really suitable if you are planning to do this afloat.

Fernox DS-40 is such a product and is based on food grade organic acids.

DS40

I assume you are planning to do this employing a similar procedure to that described in the owners manual for introducing antifreeze into the seawater system although I am not quite sure how easy it will be while afloat.

I'd warm the engine up first. Then drain the system and introduce the cleaning solution as described for the antifreeze. If you can collect the stuff that is discharged and recirculate it a bit so much the better, otherwise let it soak for while.

When you've done drain, neutralise, flush thoroughly then give it the antifreeze treatment. Note though that ethylene glycol based antifreeze should not be discharged into the marine environment either!

I have assumed that it is the seawater circuit you are talking about not the fresh water side.
 
We just took the heat exchanger off - just is relative term, like just taking your own appendix out. It can be done, but you really have to want to, or need to.
Then stood it [heat exchanger, not appendix ] in a bucket and filled it with de scaler - commercially available at the super market in France & Belgium - left it overnight and hosed it out the following morning. Amazing results from the crud that came out to the dramatic increase in water flow and no danger of damaging the engine inner works
 
[ QUOTE ]
try calgon

[/ QUOTE ] calgon is just to prevent limescale forming in washing machines. It's not a descaler.
 
[ QUOTE ]
and no danger of damaging the engine inner works

[/ QUOTE ] should be no danger to the "engine inner works" if just descaling the seawater side. It will go into the exhaust via the injection point but often these need descaling anyway!
 
On the 42`s on my old boat I took off heat exchangers, intercoolers, oil coolers and any associated pipework and filled them with brick cleaning acid available at any builders merchants. I left them over night and they came up like brand new. Washed them out and refitted. Overheat problem turned out to be a faulty earth to the temp guage in the end but she ran cool as a cucumber to the day I sold her.
 
Brick cleaner is ususlly a fairly concentrated hydrochloric acid solution. A bit drastic but if used with caution can give quick results and contains no inhibitors to prevent attck of the metal so could cause damage if allowed to react for too long.
 
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