replacing anodes.....when and what type?

[GuitarsAndTikiBars]

We have a 2003 380 SD with 8.1L horizon V drives. We have a hull anode and one anode on the top of each trim tab...and other than some scale on them, they are still pretty substantial in volume. They are the factory original anodes and are I believe zinc. The boat has only ever been in fresh water (Lake Erie and now the Ohio River)

How do we know when to replace them, and should we use magnesium for all 3? I have only found zinc in the size and shape of the hull anode.

Thanks.

 

[CV-23]

I have the same question! They say to use magnesium for fresh water. This will be the first summer I have shore power. I do have the Mercathode system on the 270/Bravo1. I need to order soon! Thanks, Mike.

 

[douglee25]

Magnesium for fresh water.

Aluminum for brackish water.

Zinc for salt water.


www.boatzincs.com for all your anode needs.

Doug

 

[Mr Salt]

One school of thought is that they should be replaced when they about 40% gone. I am in salt water and that works out for me to replace them once a year.

 

[anchoring.com]

Yup, I've always followed the once a year or half gone rule.

Of course, if you're getting a lot of build up (or no build up) you might increase or decrease that time appropriately.