Fresh water engine anode question

[Barrie]

I am in fresh water and installing magnesium anodes on my hull, rudder and drive shaft, but can't find a supplier of magnesium pencil anodes for the Cummins QSB engine. The chandlery's all seem to sell zinc anodes. This will leave me with mixed metals which I understand is not ideal. Any thoughts appreciated.
Barrie

 

[Bacchus]

When I moved to fresh water I had the same difficulty finding pencil anodes. I switched to all alum and get all my pencil anodes from Performance Metals
https://performancemetals.com/
I like their steel reinforcing in the center as it reduced breakage leaving the rod in the heat exchangers.

 

[Comodave]

You definitely don’t want zinc. But either aluminum or magnesium is good. You can run one in the engine and the other on the hull since they are different bodies of water. I ran magnesium in our engines and aluminum on the hull in our last boat. Just don’t use zinc in fresh water.

 

[Graeme Walker]

I had the same problem but used Aluminum anodes as I was going to salt/brakish water down the ICW. I talked with Boatzincs and their said that only zinc is used within engines as the environment is too severe for Al or Mn, hence the difficulty finding those. They said there would be no problem to mix anodes in this manner.



Also talked with SidePower and they only support AL.

 

[dhays]

I talked with Boatzincs and their said that only zinc is used within engines as the environment is too severe for Al or Mn, hence the difficulty finding those. They said there would be no problem to mix anodes in this manner.

I’ve used AL pencil anodes in my Cummins QSB 5.9L engine for a while now. Despite multiple anode inspections and replacements, I’ve never found them to fare any worse than the zone anodes (from Boatzincs.com) I used to use.

Since they don’t manufacture or source AL pencil anodes, I would take what they said with lots of NaCl.

 

[Comodave]

We used magnesium anodes in our last boats engines for years without any problems.

 

[Barrie]

Thanks for the information folks. much appreciated.