Fresh water engine flush and anodes

[Wdeertz]

My boat operates exclusively in salt water but have been thinking of implementing a fresh water engine flush when it will sits longer between uses. Being in salt water I’ve been using zinc anodes. Short of swapping out the zinc anodes after a fresh water flush with magnesium anodes I was contemplating putting in 1 zinc anode and 1 magnesium anode. Would this work?

I tend to use the boat for a few weeks continually and then sit at a marina for a month before moving onto my next location. I suppose swapping between zinc and magnesium anodes after a fresh water flush would be best but this would be more of a pain.

 

[DDW]

I do the same thing and have come to the conclusion that I will use aluminum anodes for everything. Aluminum works in both fresh and salt, and experts are beginning to recommend it over zinc even in salt, as the protection is slightly better and they last somewhat longer.

 

[firehoser75]

Wdeertz,
I can't speak to the conditions in Florida, but I do not change my anodes after a freshwater flush. It would be a real pain! I flush after every run if I am at a marina where they have a good suppy of freshwater. It only takes about 10 minutes! I leave the zincs in over the winter storage period (6 months) and so far (4 years) do not have a problem.
DDW's suggestion is a good one, especially if you are concerned.

 

[Wdeertz]

Wdeertz,
I can't speak to the conditions in Florida, but I do not change my anodes after a freshwater flush. It would be a real pain! I flush after every run if I am at a marina where they have a good suppy of freshwater. It only takes about 10 minutes! I leave the zincs in over the winter storage period (6 months) and so far (4 years) do not have a problem.
DDW's suggestion is a good one, especially if you are concerned.

Thanks, I’m thinking the same thing. Talking with a friend that spent 3 months in fresh water with his zincs and they hadn’t developed a hard coating. Zinc anodes will over a long time become ineffective in fresh water and get a hard coating. I don’t think 1 month of fresh water will cause this to occur so I’ll stick with my zincs.

 

[Comodave]

Why not just go with aluminum anodes? They will work in either fresh or salt water. Then it isn’t an issue.