Photos of worn anodes

Spyderweb

Most recommendations for replacing anodes are when they are down to 50% remaining by weight.  I just replaced my 4 year old Bravo3 anodes, a year longer than I had planned.  While they looked real bad to me, my before and after weights show % remaining to be much higher than I would have expected.

In the photos below, the amount remaining from top to bottom (and left to right) are as follows:
77%
62-69%
80%
73-78%

My sense is most people on this forum replace before they get this used up.

LaRea

Is that magnesium?  Mine look like that after one season.  I replace them annually.  

TonyG13

Last time I took mine off I did the same thing and weighed them and figured they were still good and I was replacing them sooner than needed. Since magnesium is the most expensive anode version I now replace every 2-3 seasons (12-18 total months in water) instead of annually. Saves some money for other things on the boat.

Spyderweb

@LaRea yes, magnesium.  Fresh water and in water about 4 1/2 months per year.

LaRea

@Spyderweb I forgot how short the boating season is at your latitude.  We're usually in the water for 7-8 months.  Also it's clear that nobody near you has electrical issues.  

rasbury

So at some point with corrosion do the become less effective? I trailer our boat and lord knows its not in the water much but I did just replace them- but they did not look that bad...

raybo3

I am in salt water and I change mine at the half way point of the season. Very cheap insurance changing zinc's vs very expensive outdrives...... Just say'n 

Ian

Spyderweb said:

@LaRea yes, magnesium.  Fresh water and in water about 4 1/2 months per year.

I just Al as per recommendations for fresh and change every 2nd season because for under $100 it’s not worth going another year.

LaRea

Here's another reason I change anodes every spring.  Suppose I don't change them, and then I get a new dock neighbor with a stray current problem.  I'd want to enter that fight with full protection rather than depleted anodes.  

Dream_Inn

I replace mine every 5 years or so whether it needs or not. Oh, yes, I'm on a lift!