Anode guidance

[pbyrne]

The boat is always in freshwater during summer months, and on the hard for about 5 months.

The prop is a variprop that has a zinc anode on it, the shaft has a zinc anode, and I'm assuming the engine is all zinc too.

I've read various things on the forum, and I'm looking for clear advice on what if anything, I should switch to.  Leave the zinc, magnesium, aluminum?

What I'd also like to know is if you can leave some zinc, and switch to some magnesium?   I ask as the magnesium for the prop is very expensive, and I don't even know if you can magnesium for the engine..?

Anyways, some reasonable combo advice would be be great.  I just want to try and protect the boat as best as possible.

[Jim Hardesty]

The boat is always in freshwater during summer months, and on the hard for about 5 months.
The prop is a variprop that has a zinc anode on it, the shaft has a zinc anode, and I'm assuming the engine is all zinc too.
I've read various things on the forum, and I'm looking for clear advice on what if anything, I should switch to.  Leave the zinc, magnesium, aluminum?
What I'd also like to know is if you can leave some zinc, and switch to some magnesium?   I ask as the magnesium for the prop is very expensive, and I don't even know if you can magnesium for the engine..?

I'm in Erie, PA.  My sailing season is similar to yours.  A few years ago I switched to magnesium anodes and was getting a rough mineral like deposit on my Maxprop.  Took me a couple of seasons to connect the two.  I've gone back to all zinc, no more deposits.  Read that magnesium would do that.  I was able to use wet/dry sand paper and polish to cleanup the prop, was no pitting.  I do cleanup the zinc each season and replace when pitted.  FWIW I don't think half year seasons and fresh water create much of a corrosion concern.  Stray current at the dock may be.   Try
WWW.Boatzincs.com
I've been happy ordering from them.
Possibly your experience with magnesium maybe different than mine.  Your boat your choice.
Jim

[Ron Hill]

Guys : When I purchase a zinc shaft anode I always get the one with a "BB" imbedded in the inside of the Zn.  It gets the best contact with the shaft as the "BB" indents into the shaft!!

A thought

[pbyrne]

Interesting.  Where do you get them from?

Guys : When I purchase a zinc shaft anode I always get the one with a "BB" imbedded in the inside of the Zn.  It gets the best contact with the shaft as the "BB" indents into the shaft!!

A thought

[Jim Hardesty]

Interesting.  Where do you get them from?

That's the way the zinc's from Boatzinc.com are made.  Think it's common.  It's good practice to clean up shaft when installing.
Jim

[pbyrne]

Thanks Jim.  Very helpful!

Interesting.  Where do you get them from?

That's the way the zinc's from Boatzinc.com are made.  Think it's common.  It's good practice to clean up shaft when installing.
Jim

[Breakin Away]

I'm not an expert, but I've been advised not to mix different metals for anodes. I believe it's because you may get extremely fast erosion from the more active anodes, and your zinc will be rendered inactive leading to potential damage to whatever is closest to the zinc. If anyone can find a pencil anode for the HX in aluminum, let me know and I'll consider changing everything from zinc to aluminum. I think that magnesium is only meant for nearly pure freshwater.