Best anode

[the butcher]

I've owned several fiberglass boats over the years but recentIy purchased a 24ft aluminum fishing boat. Can someone tell me what is the best anode to use? I am primarily fishing in Georgia straight. Google search tells me zinc is best for aluminum boats in saltwater but another search tells me aluminum alloy anodes cam be just as effective and lasts longer. It seems like you should standardize on the same type of anode for boat. I believe most outboard manufacturers have aluminum alloy anode mounted to the motor. Can't say for sure for all manufactuers but my last mercury outboard came with aluminum alloy anode on the motor.

 

[ab1752]

I've used both aluminum and zinc with no notable difference in the central and southern straits.

 

[Alan Wilson]

I would contact the builder and ask what they recommend.

 

[allanb76]

Agreed...contact the boat builder and make sure all anodes are the same. Silver Streak uses aluminum for salt water.

 

[ReelSlim]

I use zinc on my boat because that is what the builder had installed. My little SilverStreak came with a zinc anode that I haven't ever changed because it's used very little and mostly fresh water. I thought I read somewhere that both zinc and aluminum are fine to use but aluminum was recommended for brackish water.

 

[Whole in the Water]

Agreed...contact the boat builder and make sure all anodes are the same. Silver Streak uses aluminum for salt water.

Interesting. My 2004 Silver Streak came with all zinc anodes. That's all I have ever used and worked great for 20+ years.

 

[brands51]

Following this thread. Seems like everyone I’ve talked to regarding anodes on aluminum boats recommends something different. Malcom Russell was telling me 100% aluminum annodes for aluminum boats, OceansWest told me 100% zinc annodes on aluminum. Pretty undecided on what I’m going to use in the long run.

 

[Aquaholic]

Bridgeview told me zinc only on their boats in saltwater.

 

[Howzer]

I'm a little puzzled how an aluminum anode is going to be efficient at protecting a boat that is also made of aluminum as the metals are virtually the same in electrical nobility.
I would think zinc or even magnesium anodes would be better.

 

[JWS]

I'm a little puzzled how an aluminum anode is going to be efficient at protecting a boat that is also made of aluminum as the metals are virtually the same in electrical nobility.
I would think zinc or even magnesium anodes would be better.

I believe most (or all) are an alloy

 

[Flashman]

I believe most (or all) are an alloy

Seems to be the case:

How Can an Aluminum Anode Protect an Aluminum Boat?

All too often we get the question, “How can an aluminum Anode protect an aluminum boat (or outdrive)?” In particular, there is the worry that they will not be suitable for salt water. Navalloy (aluminum) anodes are not like regular aluminum. They are made from a special alloy with indium. It’s a...

performancemetals.com

An alloy of indium and zinc to eliminate the formation of the protective oxide layer that reduces corrosion of aluminum.

 

[allanb76]

Interesting. My 2004 Silver Streak came with all zinc anodes. That's all I have ever used and worked great for 20+ years.

I think both are fine, but aluminum is a little better protection. I suspect SS changed somewhat recently because most newer outboards come with aluminum anodes now and hull anode should be the same material.

 

[Fixit]

the best answer is "it depends"
aluminum anodes in theory are better. higher voltage, lesser cost, better for environment. but they have drawbacks. they can develop an oxide layer and passivate and stop working. and they dont self clean as well as zinc, slime, hard growth etc can grow.
ive used both zinc and aluminum alloy anodes on fibreglass and aluminum. I prefer how zinc stays clean, and active, and remains active until its wasted away. the aluminum anodes I have on my outboard need a wire brushing to clean them after sitting on the trailer all weekend

 

[Aquaholic]

the best answer is "it depends"
aluminum anodes in theory are better. higher voltage, lesser cost, better for environment. but they have drawbacks. they can develop an oxide layer and passivate and stop working. and they dont self clean as well as zinc, slime, hard growth etc can grow.
ive used both zinc and aluminum alloy anodes on fibreglass and aluminum. I prefer how zinc stays clean, and active, and remains active until its wasted away. the aluminum anodes I have on my outboard need a wire brushing to clean them after sitting on the trailer all weekend

Interesting points. The only time the anodes on my main outboard have shown any wear is when it got really cold in the winter and I put the leg down into the water for about a week. Other than that, they seem to perform flawlessly.

 

[Whole in the Water]

Seems to be the case:

How Can an Aluminum Anode Protect an Aluminum Boat?

All too often we get the question, “How can an aluminum Anode protect an aluminum boat (or outdrive)?” In particular, there is the worry that they will not be suitable for salt water. Navalloy (aluminum) anodes are not like regular aluminum. They are made from a special alloy with indium. It’s a...

performancemetals.com

An alloy of indium and zinc to eliminate the formation of the protective oxide layer that reduces corrosion of aluminum.

I don't understand. Why would one want to eliminate the formation of the protective oxide layer that reduces the corrosion of aluminum? One would think you want to increase this protective oxide layer?