Flushing Raw Water Cooled Bukh DV10 LSME

[keensailor]

hi
Boat lives in salt water and I want to periodically flush the motor with some fresh water etc.
Just wondering if there is anything you can put in the fresh water when flushing to help clean out any build up.
cheers

 

[VicS]

hi
Boat lives in salt water and I want to periodically flush the motor with some fresh water etc.
Just wondering if there is anything you can put in the fresh water when flushing to help clean out any build up.
cheers

Not that simple

A quick flush is not likely to do much good because until the engine reaches normal working temperature the thermostat remains closed and little or no water actually flows through the engine itself. Just through the bypass and out of the exhaust.

If needs rigging up with a continuous flow of fresh water or some sort of re-circulation system, until it is up to full temperature.

Products like "Salt Away" might help once circulation is achieved . A badly scaled system might need a descaler such as "Rydlyme" or a central heating system descaler such as Fernox DS 3 or DS 40 perhaps

 

[alan_d]

More important is to keep an eye on the condition of the pencil anode.

 

[keensailor]

More important is to keep an eye on the condition of the pencil anode.

hi alan
where is the pencil anode on a Bukh DV10 LSME?

 

[sailorbaz]

My boat which I have owned for 18 months has a raw water cooled Yanmar 1GM10. The original owner installed it in 1985 and every winter he disconnected the inlet hose and attached an extension tube which he dipped in a 25 litre container of fresh water. He ran the engine until it was nearly gone and then stuck the tube in a litre container of cheap white vinegar and stopped the engine when it had sucked it up. He left it in overnight and then put another 25 l of fresh water through.
I changed the anode last year - the old one was completely gone - and as far as I could see the waterways were fairly clear.
I haven't done the vinegar rinse myself though as I'm still not sure about it.
Has anyone else done this with vinegar? Would it be more effective with a decalcing solution?
Sailorbaz

 

[micha571]

hi alan
where is the pencil anode on a Bukh DV10 LSME?

The DV10LSME does not have a pencil anode. It is only on the "regular" DV10, not on the saildrive-version (LSME).

 

[richardabeattie]

Why not remove the thermostat cover,take out the thermostat, replace the cover and then run the engine. That way the flushing starts straight away - no need to wait for the engine to warm up. But what do people think about the white vinegar?

 

[keensailor]

The DV10LSME does not have a pencil anode. It is only on the "regular" DV10, not on the saildrive-version (LSME).

thanks again

 

[keensailor]

Why not remove the thermostat cover,take out the thermostat, replace the cover and then run the engine. That way the flushing starts straight away - no need to wait for the engine to warm up. But what do people think about the white vinegar?

my Bukh dealer here in Sydney recommended vinegar, but I think I will use Rydlyme

 

[vyv_cox]

Why not remove the thermostat cover,take out the thermostat, replace the cover and then run the engine. That way the flushing starts straight away - no need to wait for the engine to warm up. But what do people think about the white vinegar?

Acetic acid is a weak organic acid and vinegar only contains about 2% of it. Any effect it has will be minor. Far better to use an inorganic acid, hydrochloric is probably the most effective but Rydlyme is probably as good.

 

[VicS]

Why not remove the thermostat cover,take out the thermostat, replace the cover and then run the engine. That way the flushing starts straight away - no need to wait for the engine to warm up. But what do people think about the white vinegar?

my Bukh dealer here in Sydney recommended vinegar, but I think I will use Rydlyme

Acetic acid is a weak organic acid and vinegar only contains about 2% of it. Any effect it has will be minor. Far better to use an inorganic acid, hydrochloric is probably the most effective but Rydlyme is probably as good.

As Vyv says the acid in vinegar is acetic acid which is very weak acid, pKa = 4.76, although he must be buying very poor quality vinegar if his is only 2% acidity. Ours is 5%

The low concentration means it will dissolve very little in the way of scale and its weakness as an acid means it will do so relatively slowly.

Citric acid is significantly stronger, pKa = 3.13 and can be made as a more concentrated solution, up to 73g/100ml.

The strongest of the weak acids that I know of is sulphamic acid which is used in some descalers, Ferox DS-3 for example. pKa =1.0

The nature of Rydlyme is a bit of a mystery. Most of what they say about it suggests it is hydrochloric acid based, except for the pH value.

If I was still working I'd buy some and take a look at in the laboratory ... but I am not

 

[pagoda]

Acetic acid is a weak organic acid and vinegar only contains about 2% of it. Any effect it has will be minor. Far better to use an inorganic acid, hydrochloric is probably the most effective but Rydlyme is probably as good.

I have used both, having taken the head off my 3gm30 to check for scale build up. As the carbonates in sea water get precipitated out at higher temperatures than normal running, anything causing slight overheating makes it all considerably worse. More precipitation...
I cleaned up some individual parts in white vinegar , which fizzzed away in a half-hearted way, but did remove deposits. Once the engine was re-assembled - I ran it from a large bucket under the stern (water intake via a hose to said bucket) , until warm. I used patio cleaner - mostly HCl about 10%, and the froth ejected confirmed it was dissolving the internal deposits readily. (I removed the 3 internal anodes prior to this as they would have been attacked by the acid)
Exactly how much a % of the calcified deposits were removed - I don't know... but there is no longer any steam in the exhaust!
I would do it again is need be.
Take care with the acid- gloves / specs etc...

Graeme

 

[GrumpyOldGit]

My boat which I have owned for 18 months has a raw water cooled Yanmar 1GM10. The original owner installed it in 1985 and every winter he disconnected the inlet hose and attached an extension tube which he dipped in a 25 litre container of fresh water. He ran the engine until it was nearly gone and then stuck the tube in a litre container of cheap white vinegar and stopped the engine when it had sucked it up. He left it in overnight and then put another 25 l of fresh water through.
I changed the anode last year - the old one was completely gone - and as far as I could see the waterways were fairly clear.
I haven't done the vinegar rinse myself though as I'm still not sure about it.
Has anyone else done this with vinegar? Would it be more effective with a decalcing solution?
Sailorbaz

Hi,

The vinegar method is well tried and tested for scale removal in S/W cooled engines and a lot of marine engineers also use ' Disclean' Brick cleaner to clear the waterways. Simply fill the engine through the water inlet by whatever means suit your circumstances and the LEAVE to stand overnight. Flush through with fresh or sea water and hey presto! Clean waterways. Don't forget the internal anodes as they are the protectors inside the engine !!!

 

[DaveS]

Hi,

The vinegar method is well tried and tested for scale removal in S/W cooled engines and a lot of marine engineers also use ' Disclean' Brick cleaner to clear the waterways. Simply fill the engine through the water inlet by whatever means suit your circumstances and the LEAVE to stand overnight. Flush through with fresh or sea water and hey presto! Clean waterways. Don't forget the internal anodes as they are the protectors inside the engine !!!

When I cleaned out my clogged up VP2002 earlier this year using HCl brick cleaner I found that it fizzed very vigorously for about 10 minutes then quickly died down to no apparent activity. I concluded that at that point the supply of either acid or alkaline deposits had been used up, and drained it, flushing out lots of rubbish. In retrospect I should probably have tried another dose of acid to confirm that it was the alkali that was all gone, but in disposing of the spent acid and rubbish I accidentally splashed the previously removed zinc anode which immediately started to produce bubbles, so I think that was reasonable confirmation that some active acid was left and that the alkali was all gone.

 

[PedroPV]

Hi. I have a VP 2003 raw water cooled and I'm thinking of descaling to get rid of carbon , salt and lime deposits.
Has anyone tried Starbrite descaling fluid?
Is it not too strong? I'm afraid of damaging seals.
Thanks.