Magnesium sacrificial anodes

[robbjd]

I have a 1" zinc anode on the prop shaft and a "J" prop zinc that probably would protect for another season. I have zinc spares for both, but found magnesium replacements for both at prices too low to walk away from. The weight difference is substantial (1#11.5oz vs. 7 oz) and that can only be good for vibration reduction as well. We'll only sail in fresh water so magnesium seems to make the most sense. Does anyone have a two blade "J" prop (15.5" dia.) on their 34? My pitch had been set at position 7 which equals 8.6" and had vibration issues above 2200 rpm. I'm wondering if the pitch setting is incorrect causing cavitation?

[Jim Hardesty]

Can't answer about the pitch or vibration.  Only to say first thing I'd check the cutlass bearing.  My experience with magnesium anodes are here.

https://c34.org/bbs/index.php/topic,10771.msg84066.html#msg84066

Jim

[KWKloeber]

 Possibly a shaft whip?  Check to see if the shaft is true (and don't put the anode in the middle of the span.)