How often do you flush your raw water side with Salt-Away or equivalent?

[Suijin]

Title speaks for itself. How often do you flush your raw water side, either in terms of engine hours or seasons. I'm interested specifically in diesel on sail that live 365/year in salt water.

Thanks.

[slug]

Originally Posted by Suijin

Title speaks for itself. How often do you flush your raw water side, either in terms of engine hours or seasons. I'm interested specifically in diesel on sail that live 365/year in salt water.

Thanks.

Never used anything special

I do fresh water flush the engine at the end of sailing season

[sailormed]

In the marina here in the Med, all sailing boats spend 365 days a year in the water, nobody ever flushes the seawater side.

[Compass790]

We have a raw water cooled Yanmar that we dont seem to have to use any acid treatment on. We do flush with fresh water when we get back to marina each time so it sits with fresh water in it. Not sure if that helps or not with scale buildup. Can't hurt was my reason for doing it & to help anode life.

[slug]

Sea water rapidly becomes anaerobic

Anaerobic conditions are very hard on stainless steel

Pump shafts , valves ....

[basssears]

Think I'm in different scenario than you, but do use Salt Away so will answer.

Our boat lives in the water 365 days a year, but I use it in blocks and then go away from it for months at a time. I have taken to flushing my raw water side with fresh water and Salt Away and leaving that to sit in the raw water side every time I leave the boat for a few weeks / few months.

It seems to be helping with buildup, and I can definitely tell that my heat exchanger zincs aren't being depleted as quickly.

Overall hard to say how much the Salt Away helps, but leaving raw water circuit full of fresh has to help.

-- Bass

[MartinR]

Never! Why would I?

[MJH]

Originally Posted by Suijin

Title speaks for itself. How often do you flush your raw water side, either in terms of engine hours or seasons. I'm interested specifically in diesel on sail that live 365/year in salt water.

Thanks.

This topic has been asked before but I still have the same questions.

On my previous smaller boat with a Yanmar I never used anything during the 11 years of ownership and never noted a problem other than replacing the exhaust elbow. Now with a larger boat with a Volvo Penta I have used Barnacle Buster once during 12 years but I don't see any change. Both boats were in salt water 365/year.

I don't know of any "independent" source that has actually completed a BEFORE-and-AFTER test and reported the findings. The test would be a lot of work, first tearing the engine down to document the buildup then build the engine back up again, next to complete the flush, then to tear it down again to document the cleansing and lastly to put the engine back together again.

If anyone has found an "independent" documented study please share it with this forum. FWIW, I have shared this test request with Practical Sailor magazine many months ago but never received a reply which is not uncommon.

~ ~ _/) ~ ~ MJH

[Tupaia]

If your heat exchanger has an anode (pencil type is typical) this will be zinc. If you fill the cooling circuit with fresh water it wont work as it would require a magnesium anode. Aluminum components are particularly at risk. If you are leaving the boat for a long time it is worth flushing then filling with antifreeze as this contains anti corrosion additives.

[bailsout]

I freshwater flush after every use. Just part of the postsail routine.

[Lambretta]

I flush both my yanmars with Salt Off if they are going to stand for me than a week. I fitted Perko Flush Pros on both engines and on my generator. It is a simple plug and play system so super easy to do. I have not had to use my genny for over 4 months due to large solar and I dont need shore power either. So my view is "keeping" them in fresh water is always going to be better than "keeping: them in salt water.
I also have a Mastercraft X Star and I have seen what even brackish water does to manifolds and risers even though they get flushed after a weekend of use as I have looked inside these ..... its not pretty!

I will also use barnacle buster from time to time through these flush kits

[Tingum]

Never! Your post says you are in Exuma, ever see any one there ever flush an engine?

[kmcshane]

I fresh water flush my 3GM30F Yanmar heat exchanger and mixing elbow before I leave for hurricane season from South Florida. I have taken advice and use this product when I return: Barnacle Buster. Kinda pricey by the gallon but can be used for four years when diluted as directed; biodegradable, and easy to use. Here's a promotional video:

https://www.youtube.com/watch?v=u4bGiv2MD74

[a64pilot]

Never, but I do disassemble and clean my heat exchanger every other year. I believe that keeps it cleaner than any chemical cleaning, and maybe less damaging.

[OloteleMtn]

I recently r&r'd my Yanmar raw water cooled 2QM20 engine head for loss of power diagnostics; the cooling passages were completely blocked (boat was recently purchased)by mineral deposits, with zincs fully degraded. Drains were nonfunctional due to the same. A mixture of water and muriatic acid removed the deposits; the service manual specifies a proprietary solution to accomplish the same annually. The last owner had the boat 10 years and was not an engine guy :/