Aluminum Anodes

[Art]

My decades of anode protection...

Saltwater = Zinc

Brackish water = Magnesium and Zinc

Freshwater = Magnesium and Zinc

NOW - In freshwater I plan to install aluminum anodes this month

With zinc in freshwater I needed to scrub their surface clean each 3 +/- months to keep them active. Mag zincs worked well in brackish or freshwater while disintegrating rather quickly. At times I'd have mag and zinc installed/working at same time.

Until the near future I've not used aluminum anodes. Will be interesting to see how well they function.

I'm interested to learn reports from those who are accustomed to aluminum anodes in freshwater. From what I've been reading aluminum anode has gained recognition as being a good choice for use in most if not all water compositions. For reasons... zinc is falling out of favor. And, as always known, magnesium sheds too quickly in saltwater... but performs well in freshwater - although still shedding at a fairly quick rate.

What do you think of aluminum anodes?? ... I just ordered a bunch for freshwater use!

 

[dhays]

I have been using aluminum anodes for about a year and a half now. I boat exclusively in salt water, but I do a fresh water flush of my engine after I return to my dock. So the anodes sit in fresh water for most of the time.

So far, so good. However, to be honest I wouldn’t really be aware of any problems at this point.

 

[Bacchus]

They seem like a perfect choice in your situation..
I'm in fresh water and switched to alum Performance Metals Anodes for all my engine anodes.
Very pleased with performance and availability from them. Some of mine erode at faster rates than others so important to check more often to start to get a feel for frequency of change. The PM pencil anodes all have a center steel rod to minimize breakage... a plus in my book.

 

[rslifkin]

I'm using aluminum anodes on my boat in fresh water. They're wearing and I'm showing no corrosion issues, so I'd say they're working.



In really clean fresh water, you may need magnesium (more active than aluminum), but if you go back and forth to salt water, or if you're in more conductive (dirtier) fresh water, aluminum will do the job.

 

[Art]

I'm using aluminum anodes on my boat in fresh water. They're wearing and I'm showing no corrosion issues, so I'd say they're working.



In really clean fresh water, you may need magnesium (more active than aluminum), but if you go back and forth to salt water, or if you're in more conductive (dirtier) fresh water, aluminum will do the job.

The water we're in [SF Delta - receiving freshwater off the mountains] may even be slightly brackish upon different tides. Especially regarding the record setting drought we're currently experiencing.

 

[Art]

Dear Mods... Why do you think I'm not receiving email notifications to posts on this thread that I began yesterday??

I need to go searching to locate the posts from others.

I just went into my signup details; all seems in order.

Weeks ago I was not receiving email notifications from any thread to which I'm entailed. When I checked my details then the listed state had been unexplainably altered from California to Alabama. Upon changing it back the email notifications resumed.

Now I wonder how many posts from differing threads I may be missing?

Suggestions appreciated!

 

[kchace]

My boat is kept in brackish water but I usually am boating in salt water. I have been using all aluminum anodes for at least 5 years and so far all is well. They seem to erode at almost the same rate as zinc did. No known issues regarding protection.


Ken

 

[Art]

My boat is kept in brackish water but I usually am boating in salt water. I have been using all aluminum anodes for at least 5 years and so far all is well. They seem to erode at almost the same rate as zinc did. No known issues regarding protection.


Ken

Dear Mods - I did not get email notice on this post either. Had to go TF website "fishing" to find it??? Can you assist me in trying to get so my email receives new post notifications - Please! - Thanks, Art

 

[Comodave]

I use aluminum in fresh water and usually get 2 years out of them.

 

[Larry M]

Art: PM regarding subscriptions sent.

 

[Larry M]

We used aluminum anodes for 6 plus years in brackish/fresh water. In the summer time the water is fresh. Prop, running gear are fine. Check the source and specifications of the anodes though. They aren’t pure aluminum is my understanding.

 

[dhays]

Like others here, I have been using AL pencil anodes made by Performance Metals. The only way I can buy them is to call the company and order by phone. Not the most convenient given the 3 hour time difference from me but they are always very helpful and quick to ship out.

Anyone have any other source for the aluminum pencil anodes?

 

[Graeme Walker]

I changed to Aluminum alloy anodes last year on recommendation of Martyr. We boat in fresh water but plan to go to salt water for a several months. I did notice after last year they had eroded slightly in fresh water, exactly what we want to happen. I called Cummins and they still recommend zinc pencil anodes for the engines due to very severe environment, Martyr agreed with that assessment.

 

[dhays]

I changed to Aluminum alloy anodes last year on recommendation of Martyr. We boat in fresh water but plan to go to salt water for a several months. I did notice after last year they had eroded slightly in fresh water, exactly what we want to happen. I called Cummins and they still recommend zinc pencil anodes for the engines due to very severe environment, Martyr agreed with that assessment.

Graeme, I’m not sure what they mean by “very severe environment”? Fresh water?

I would be concerned about using zinc anodes in fresh water since they become less active as they develop a hard coating.

If I could get aluminum anodes for my thrusters, I would consider changing out the anodes on all the external metal to aluminum as we all my engine’s pencil anodes.

 

[Graeme Walker]

Cummins said any anode within the engine should be zinc, fresh water, brackish or salt. I had zinc before the aluminum in fresh water and they did develop a coating, no noticeable damage however. Martyr did not recommend Mg if going to salt water. I changed over thrusters, trim tabs, and shafts to Al. Kept zinc in Cummins and Westerbeke generator.

 

[Art]

I changed to Aluminum alloy anodes last year on recommendation of Martyr. We boat in fresh water but plan to go to salt water for a several months. I did notice after last year they had eroded slightly in fresh water, exactly what we want to happen. I called Cummins and they still recommend zinc pencil anodes for the engines due to very severe environment, Martyr agreed with that assessment.

Martyr are aluminum anodes I just ordered. Thanks everyone for incites to your aluminum anode experiences/feelings.

 

[Art]

Art: PM regarding subscriptions sent.

Larry - 50 minutes ago I sent you a PM reply to your PM.

So far I've three times gone through every portion of my "User CP"; with a fine tooth comb. Can find no irregularities. Even changed my password but maintained same name and email address. Then signed back in. Still no TF email notifications. I have to open into TF to search onto threads I know I'm connected to as well as to locate new PM's. My email receives incoming from other sources as well as sends to others. It even sends and receives to itself.

I've no idea why TF email notifications are not coming through. I'm stumped. And, TF threads/posts are needed to keep me "on the level"... centered so to say - LOL Sure hope this can be figured out!

 

[catalinajack]

Graeme, I’m not sure what they mean by “very severe environment”? Fresh water?

I would be concerned about using zinc anodes in fresh water since they become less active as they develop a hard coating.

If I could get aluminum anodes for my thrusters, I would consider changing out the anodes on all the external metal to aluminum as we all my engine’s pencil anodes.

Boatzincs.com had aluminum anodes for my Sidepower thruster.

 

[Bacchus]

Graeme, I’m not sure what they mean by “very severe environment”? Fresh water?

I would be concerned about using zinc anodes in fresh water since they become less active as they develop a hard coating.

If I could get aluminum anodes for my thrusters, I would consider changing out the anodes on all the external metal to aluminum as we all my engine’s pencil anodes.

I had a discussion with SidePower when I bought our boat and was switching.
They recommend alum for all applications
They indicated there is no need to have the same anode material as the rest of the boat as the thrusters are "isolated" from the other metals on the boat.
I believe the only thruster anodes they now sell are all alum.
They are relatively easy to find from multiple sources.

 

[dhays]

Thanks Bacchus and Jack. I’ll check to see if they are available for Vetus.

 

[Steve DAntonio]

Aluminum anodes are a win-win, they are effective in fresh, brackish and salt, there is no drawback. More here https://stevedmarineconsulting.com/galvanic-isolators-and-zinc-anode-selection/

The only issue I've had with aluminum anodes is with pencils used or heat exchangers. Aluminum is more reactive than zinc and as such it develops a white aluminum hydroxide froth on the surface. This has no effect on how well the anode works, but it can make pencil anodes difficult to remove. There's no harm in using zinc on heat exchangers and aluminum on the hull.

From ABYC...

 

[Art]

Aluminum anodes are a win-win, they are effective in fresh, brackish and salt, there is no drawback. More here https://stevedmarineconsulting.com/galvanic-isolators-and-zinc-anode-selection/

The only issue I've had with aluminum anodes is with pencils used or heat exchangers. Aluminum is more reactive than zinc and as such it develops a white aluminum hydroxide froth on the surface. This has no effect on how well the anode works, but it can make pencil anodes difficult to remove. There's no harm in using zinc on heat exchangers and aluminum on the hull.

From ABYC...

Thanks for your input. Can't help but wonder how come it took soooo many decades to come to this conclusion that aluminum anodes are the best material to use. Had not any anode manufacturers done comparison tests... over many decades? Or, is it that now a "new" mix of metals has aluminum as the predominant in an alloy that finally become available?