AlphaOne Anode Fin.....Need?

samm835

Chief Petty Officer
Joined
Dec 12, 2006
Messages
575
I have a fairly new to me boat, I have had an inboard for the last ten years so getting used to a i/o again is taking a little getting used to. When I bought this boat, the anode was taken off. I didn't think much about it to be honest, but I can't tell if it's just me getting used to this boat/drive or if that fin helps at slow speeds. I have had boats for around 18years......and as dumb as it may seem, I never knew what the hell these things did. Never needed to replace one, so never did any research. Thanks for the help.
 

spdracr39

Lieutenant Junior Grade
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Aug 30, 2010
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1,238
Re: AlphaOne Anode Fin.....Need?

You only have one if your boat does NOT have power steering.
 

haulnazz15

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Mar 9, 2009
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3,720
Re: AlphaOne Anode Fin.....Need?

Well, it depends on the boat. The anode "fin" was typically only used on boats without power steering in order to counteract the torque from the prop. If your boat has power steering, it doesn't need a fin, but it should have a flat anode in the same location to combat electrolysis. If you don't have power steering, then your steering is typically more difficult and will usually pull to one side if no fin is present.
 

Chris1956

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Mar 25, 2004
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28,074
Re: AlphaOne Anode Fin.....Need?

The Anode had two purposes. One was to assist in overcoming torque, usually when cruising at typical trim positions. P/S halps in this instance, and a lot of the MerCruisers had it. Second purpose was to help combat electrolysis, and that is important, as most I/O outdrives need to be left in the down position.

My advice is to get the largest anode that will fit, as there are at least three kinds. If you have a prop with extra rake, you cannot use the std anode.
 

samm835

Chief Petty Officer
Joined
Dec 12, 2006
Messages
575
Re: AlphaOne Anode Fin.....Need?

Thanks for the help and understanding of this anode fin, I have a Renken 210, merc 4.3 Alpha drive with power steering. I guess I will pick one up this week......and put back on, not gonna break the bank I think they are around 20 bucksish. Thanks again.
 

haulnazz15

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Mar 9, 2009
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Re: AlphaOne Anode Fin.....Need?

Remember, if you have power steering you DON'T need the fin, but there should be a FLAT anode tab there.
 

GA_Boater

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May 24, 2011
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49,038
Re: AlphaOne Anode Fin.....Need?

If it's been taken off for some reason, you probably need the bolt as well.
 

Chris1956

Supreme Mariner
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Mar 25, 2004
Messages
28,074
Re: AlphaOne Anode Fin.....Need?

Gee, I always used one with the small fin. It was the same price as the flat one, and had more zinc to be eaten away.....
 

haulnazz15

Captain
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Mar 9, 2009
Messages
3,720
Re: AlphaOne Anode Fin.....Need?

Gee, I always used one with the small fin. It was the same price as the flat one, and had more zinc to be eaten away.....

Depends on the need for it. I have the original anode fin on my 1976 runabout with around 800 hours of run time, and the tab is just barely pitted on the leading edge. Likely as much from sand/debris as from electrolysis. If he isn't in salt, having more anode material is probably moot.
 
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