aluminun sacraficial anodes

[garyd]

Instead of Zinc any thoughts I picked up two (2") for the drive shafts one each installing them tomorrow.

have fun boating garyd.

 

[Dustoff44]

Aluminum is for fresh water, It has a higher nobililty than zinc. Meaning it will outlast the zinc in salt water if you have Nibral props ( very common on Hatts ) That is ( Ni ) Nickel ( br ) Bronze and ( al ) Aluminum. Which aluminum will errode first the sacrifical one or the AL in the props ?
Fresh water is a total different chemistry. Just my 2C's

 

[lisaann]

i have expierence with zincs on mercruiser bravo three stern drives these are the twin prop drives.these drives have two polished stainless props and an aluminum case the problem is that can't get two months out of a set of anodes,switch to aluminium anodes and they will last the whole season. Mercruiser says zinc is a better sacraficial anode, but no zincs is bad. so if you can't change zincs mid season use the aluminum. the end result is use the zinc anodes if they last to the next haulout.
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