Flushing engine through

[MJWB]

FLUSHING THROUGH
VP 2002 raw water cooled. UK. Boat is in a harbour which gets a lot of silt coming down the river, so at times some silty water goes through the engine. It does get flushed through with clean salt water when the boat goes to sea but I'm concerned about potential build up of unwanted stuff in the engine, including salt for that matter.

Please can anyone recommend a product to use for flushing the èngine through from time to time to clear rubbish and help prevent the build up of unwanted material?

I have a vague recollection of reading that brick cleaner could be used but can't now find anything about that. Might be imagining it! Any suggestions appreciated, thanks folks.

 

[Stemar]

Brick cleaner will clear lime deposits from the engine. It will also clear your exhaust elbow. It is, unsurprisingly, quite acidic, so old clothes, gloves and eye protection are de rigeur.

However, I wonder if it would do anything for silt, which a quick search suggests is likely to be most silicates.

 

[ash2020]

Forgive me if I've misunderstood but if the boat is afloat, I don't think you should be flushing chemicals like brick cleaner into the harbour.

 

[oldbloke]

The sea is absolutely chukka with Chlorine ions already and the hydrogen ions will mix with the carbonate to form chalk. Gallons of it in an enclosed volume would change the pH , but no problem in ordinary circumstances

 

[ridgy]

Brick cleaner will clear lime deposits from the engine. It will also clear your exhaust elbow. It is, unsurprisingly, quite acidic, so old clothes, gloves and eye protection are de rigeur.

However, I wonder if it would do anything for silt, which a quick search suggests is likely to be most silicates.

I don't think flushing a bit of brick acid for afew minutes will touch an exhaust elbow. It needs to be taken off, soaked and scrubbed, multiple times.

 

[LittleSister]

If loose silt is the issue then running at high/maximum engine revs in non-silty water will likely be the most effective method of removal.

The use of brick cleaner or specialist products such as Rydlyme is for a different job. That is removing the deposits of salts/limescale etc. that build up on the surfaces of the cooling channels in a raw water cooled engine (especially quickly if it has been running too hot - typically the result of already congested channels or the wrong or failed thermostat). It does this by softening and dissolving those deposits. That is most effectively done by disconnecting engine hose connections and repeatedly recirculating the solution through the engine while it's stationary (typically using a separate portable pump and bucket) until it stops fizzing (which means either the solution has used up all its potency or there are no further deposits). I can't imagine running such solutions once through the engine at normal cooling flow speeds will achieve much at all.

 

[vyv_cox]

What Little Sister says is good advice. To remove carbonate scale you will be as well off filling the stationary engine with acid through the highest point, wait until fizzing stops, then start the engine as normal. Pumping acid through in a loop may be marginally more effective for a good deal of hassle.

Once reacted there will be very little acid left and a few more chloride ions will not harm the sea. People have used phosphoric acid for the same job but this might be less environmentally acceptable afloat.

 

[LittleSister]

. . . To remove carbonate scale you will be as well off filling the stationary engine with acid through the highest point, wait until fizzing stops, then start the engine as normal.

I hadn't thought of doing it that way, but will use to for my upcoming planned descale. That way will save me several good deals of hassle, due to 'complications' with the relevant cooling system connections on my engine. Thanks for the tip.

 

[Stemar]

I don't think flushing a bit of brick acid for afew minutes will touch an exhaust elbow. It needs to be taken off, soaked and scrubbed, multiple times.

Correct. Take the elbow off and soak it in brick cleaner for several hours.