Engine zinc anodes ok for fresh water?

[Pat T]

Brought my boat from salt water to fresh water last year. It's on the hard now and I'm changing all the underwater hull anodes to magnesium. Purchased the magnesium anodes from Boatzincs. When I asked about anodes for my CAT engine he said I was ok using the zinc anodes because they are considered in a different body of water -may not be the exact words, but I have read the same thing once or twice in my internet searches. What do you think? If you do need magnesium anodes for your CAT 3208TA's, where do you get them? I have 7 of them. Thanks.

 

[Fish53]

Magnesium if you can find them, zinc won't do much in freshwater.

 

[Comodave]

Yes, the engine is considered a different body of water. But you don’t want zinc anodes in freshwater. The zinc will get a coating on it and will become ineffective. If you can’t get magnesium anodes then use aluminum anodes. Aluminum anodes are good in any type of water, fresh, salt or brackish.

 

[Bacchus]

Performance Metals is my preferred & recommended source for alum engine pencil anodes. Alum much easier to find than magnesium.
You might consider eventually changing all to alum when you run out of magnesium.
Mix is OK as long as different "bodies" of water and electrically isolated.