Zincs or Anodes in fresh water

[chipahoy72]

I have had a 33' cabin cruiser in fresh water on the potomac river for 26 years... My boat has an inboard engine, stainless shaft, bronze rudder and prop... I have always used zincs for protection and have never had any problems... Now in the past several years I am being told that you need magnesium in fresh water... They are much more expensive, don't last as long and in most cases have to be ordered... I can understand using them on outdrives but on inboads ( providing there not aluminum) , I don't see the need. I would appreciate some feedback.

 

[Mischief Managed]

Re: Zincs or Anodes in fresh water

Zinc is fine for your application. Magnesium is best with aluminum parts in fresh water.

 

[tpenfield]

Re: Zincs or Anodes in fresh water

zincs are anodes . . . magnesium's are anodes

Mags for fresh

 

[Thalasso]

Re: Zincs or Anodes in fresh water

I have had a 33' cabin cruiser in fresh water on the potomac river for 26 years... My boat has an inboard engine, stainless shaft, bronze rudder and prop... I have always used zincs for protection and have never had any problems... Now in the past several years I am being told that you need magnesium in fresh water... They are much more expensive, don't last as long and in most cases have to be ordered... I can understand using them on outdrives but on inboads ( providing there not aluminum) , I don't see the need. I would appreciate some feedback.

I'll bet your Zincs don't wear out in fresh water. The metals ( stainless and bronze) aren't what you would call dissimilar metals like aluminum and stainless. They are pretty close on the galvanic metals chart.

Google Metals Galvanic Compatibility Chart and you will see that your metals are right next to each other on the chart. I know people that have had there boat (In boards) in fresh water for 10 years and never changed there Zincs