Sacrificial anodes on an aluminum hull - Advice needed

[Emerger]

When it comes to sacrificial anodes on an aluminum hull is one enough or is it the more the merrier? Mine has a single anode on the transom. Would adding more to the hull be better or would it cause more problems than it solves?

 

[ShoestringMariner]

When it comes to sacrificial anodes on an aluminum hull is one enough or is it the more the merrier? Mine has a single anode on the transom. Would adding more to the hull be better or would it cause more problems than it solves?

This thread might get more responses if it was posted in the main tech section instead of a manufacturers section, perhaps one of the moderators can move it?

I’d like to know the answer to this myself. I have an aluminum hull and the only anode I have is in the motor. Wondering if I should add one to the hull also.

 

[Watermann]

Not ever had an anode attached to my Al hull, just the motors / outdrives. You would want to have one if mooring the boat for extended periods of time where there's shore power out to the moorings.

 

[SHSU]

Same here. When I was going crazy during my build, @Watermann is the one that told me to keep it simple. Even though I am in salwater most of the time, we don't dock by any power nor are we in the water longer then 12 hours. So the anode on the motor seems to be enough for us.

SHSU

 

[utelectrode]

Maybe you should try more anode.

 

[MNhunter1]

Of my three hulls, the only one that had an anode was my MR180, which I believe was standard from the factory. I plan on putting it back on as I have it and the holes are already there, but I never even considered it on my other two hulls. Not sure if the MR or Mariner models were viewed as more likely to be run in salt water, or what the rationale was behind it.

 

[SHSU]

Of my three hulls, the only one that had an anode was my MR180, which I believe was standard from the factory. I plan on putting it back on as I have it and the holes are already there, but I never even considered it on my other two hulls. Not sure if the MR or Mariner models were viewed as more likely to be run in salt water, or what the rationale was behind it.

How is it secured thru the hull? Just a bolt and 5200?

SHSU

 

[MNhunter1]

How is it secured thru the hull? Just a bolt and 5200?

SHSU

Yes, minus the 5200. I'll add some on the re-install.

 

[ShoestringMariner]

Thinking about it now, I wonder if mine would’ve benefitted from having one. I believe it was originally outfitted with a 1975 mercury 650 that I got it with. I’ve since sold the motor but I don’t recall it having an anode on it. My boat had quite a few rivets that had corroded and pitted deeply, some to the point where they were hard they recognizable as rivets. There was also some pitting in areas on the bottom of the boat, especially the keel and strakes. The motor was mounted on plywood with its clamps to the bare wooden transom, so very little metal contact between the motor and the hull. (only if and where the through bolts touched the transom skin or where the motor rested on the aluminum transom trim/cap channel. And saying this I don’t know if there’s any bearing on this being a plus or minus regarding hull corrosion. would like to know actually and it might be helpful for the OP?

 

[SHSU]

The motor was mounted on plywood with its clamps to the bare wooden transom, so very little metal contact between the motor and the hull. (only if and where the through bolts touched the transom skin or where the motor rested on the aluminum transom trim/cap channel. And saying this I don’t know if there’s any bearing on this being a plus or minus regarding hull corrosion. would like to know actually and it might be helpful for the OP?

I test my anode for connectivity between it (skeg) and different metal points on the hull. Thus far, I have gotten clean signals of connectivity whenever I have tried. Think its the thru bolts that are conducting the signal.

SHSU