Re: Remedy for seawater causing oxidation on Onan parts


rossirossix4
 

Great advice.  Let me add an additional step to consider.  Before making an impeller change for the generator or the engine, consider flushing fresh water through the raw water system.  That way, even if you do spill you will be dealing with fresh water.  This is easy to do.  Close the salt water intake (you will do this anyway) then remove the top of the strainer.  Use your shore-water hose (or a cockpit shower hose) to keep the strainer full  while running the generator or engine. If you need a higher flow to keep the strainer full the hose can be augmented with a jug of fresh water.  Run the motor and water long enough to displace any salt water in the strainer body and to ensure that fresh water has replaced the salt water in the feed, impeller, and heat exchanger.  Flushing with fresh water is also a good idea if you are at the dock or on the hard and do not plan on running the engine or generator for a time.  You can also flush the AC, anchor wash. and toilet feed pumps and lines.  Fresh water reduces oxidation, helps to dissolve salt residual, may reduce hose odors, and reduces galvanic corrosion.  Our Super Maramu has a ball valve between the salt water manifold and the desalinator feed so you can shut this if you are using chlorinated dock water.  It is important to let the various systems pull the fresh water with their respective pumps--motor impellers, AC pump and system, anchor wash pump, toilet pumps--forcing fresh water through a motor using a plumbed in hose connection runs a high risk of filling the lift mufflers and forcing water into the engine via the exhaust. 
Bob KAIMI SM 429

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