Anode Life in Fresh Water?

[ran007]

Hey guys... new here...

I've had a SeaRay w/3.0L Merc stern drive sitting in a freshwater slip since March 1st, and have noticed that the anodes have become horribly corroded. What is the average lifespan of these things, and if I should replace, where the absolute best place to order them? Also, would a corroded anode affect WOT performance?

thanks!

rr

 

[bruceb58]

Re: Anode Life in Fresh Water?

How much material is left on the anode? Should replace when they are half eaten away.

 

[jam1ej20]

Re: Anode Life in Fresh Water?

Sounds like you've got a problem, loss of ground somewhere. You shouldn't be able to notice much difference between march and now in fresh water. anodes don't have anything to do with WOT performance, they're there to save much more important and valuable metallic pieces that you don't want corroding away.

 

[ran007]

Re: Anode Life in Fresh Water?

Thanks a lot you guys for weighing in. The anode is corroded, but not eaten away like I made it sound.

The slip is powered, with 120V GFCI connections all around. I have a single outdoor extention cord going into the boat plugged into a non-ground battery tender.

So I guess what ya'll are saying is that my milage will vary depending on the current in the water, type of water and if there is power going to the boat. I guess a battery switch would be a very good idea to have.

 

[bamadave]

Re: Anode Life in Fresh Water?

According to the Merc pro's, you should use aluminum anodes in fresh water now. They come in zinc, magnesium, and aluminum.
You can measure for current in the water by measuring between the outdrive and water to see if there is any abnormalities in the current. Strange enough, through my own investigation, the closer you are to a hydro-electric dam, the more of a problem there is with the anodes dissolving.
Hope this helps.

 

[ran007]

Re: Anode Life in Fresh Water?

Wow! That's amazing, but makes sense about being to close to hydroelectric damns. Not a case here.

I'm just a little concerned about an outing yesterday where the boat would not go over 50% power. Just felt like something was dragging. Up to a couple of weeks ago, it ran like a champ! I'm eliminating the Anodes, and going to the fuel filter/seperator to be the possible cause. I may start a new thread on this.

Ironicaly, the battery was flat dead when we got there (even with the battery tender on it showing green light). I don't think the two problems are connected. The battery was 4 years old with only 30Hrs on the engine a 10 minute trip to wal-mart fixed that.

 

[Bondo]

Re: Anode Life in Fresh Water?

I'm just a little concerned about an outing yesterday where the boat would not go over 50% power. Just felt like something was dragging. Up to a couple of weeks ago, it ran like a champ!

Ayuh,... How much of a Biosphere do you have growing on the bottom,..?? That'll Slow your boat....

My take, its a GOOD thing to see the anode corroding, that's its only purpose for existing and is a sacrificial part meant to protect the outdrive from the corrosion.

Ayuh,... My Take,.... They're there for Prevention....

I don't have an electrolisis issue anymore,...
And,..Few years runnin',... my anodes are still lookin' almost New, to partly cloudy...

 

[ran007]

Re: Anode Life in Fresh Water?

Ayuh,... How much of a Biosphere do you have growing on the bottom,..?? That'll Slow your boat....

I looked at it and yes, it's extremely built up with thick growth on the bottom. Could this cause that much drag?

If so, should I pressure wash it?

 

[Bondo]

Re: Anode Life in Fresh Water?

Could this cause that much drag?

Oooooooh Ya,.... That'll do it....

 

[ran007]

Re: Anode Life in Fresh Water?

Yep - so after worries of why the boat was soooo slow, I took it out of it's slip, and pressure washed the underside. I removed about a 1/4 inch of 'carpet' moss that grew on the bottom. Put it back in the water and hit full speed at WOT. Awesome!

Took about 3 hours. Never doing it again myself - gonna pay someone next time.

 

[Bondo]

Re: Anode Life in Fresh Water?

Ayuh,... Simply Amazin',... Ain't it,..??

 

[WizeOne]

Re: Anode Life in Fresh Water?

Ayuh,... Simply Amazin',... Ain't it,..??

It's called friction, isn't it?

 

[mylesm260]

Re: Anode Life in Fresh Water?

Thanks a lot you guys for weighing in. The anode is corroded, but not eaten away like I made it sound.

The slip is powered, with 120V GFCI connections all around. I have a single outdoor extention cord going into the boat plugged into a non-ground battery tender.

That could be you're problem right there. A couple things to know about electricity.

Transformers are floating. Because the battery charger you are using does not have a ground, you may have a voltage differential between the - output of the charger and absolute ground. This will create electrolysis between the floating - output and the path to ground. In you're case it's your metallic drive/anodes and salt-water .

GFCI plus are never 100%. I recently bought a house, and the house inspector used a device to test the GFCI plugs in the bathroom and outside. 3 out of 6 plugs failed the test, even though when you test them using their own built in test button they trip. In theory, if you DID have current leaking to ground through your drive, it SHOULD trip the GFCI circuit, but not all GFCI plugs have the same sensitivity. Many of them can still allow a small amount of current to "leak" out of the circuit and not trip them.


Most battery chargers will tie their "floating" transformers to something. More specifically, they will tie their - output to ground. Seeing as how you're charger has no ground connection, it cannot be tied to ground, and thus could be causing the corrosion.

A simple way to test:

connect you're charger, and use a multi-meter to measure the voltage differential between your - battery terminal, and the ground on the extension cord (the ground that your charger is not using)

Try looking for Mili volts in both AC and DC modes (because of the bridge rectifier in the charger, I'm not sure if the overall voltage differential will be AC or DC)

If you see any measurable voltage between your - terminal (also you're drive) and ground, than you should either

A) Buy yourself a new charger (with a ground)
or
B) Tie your charger to ground, by running a wire from the ground on the extension cord to your - battery terminal.

 

[Alumarine]

Re: Anode Life in Fresh Water?

the closer you are to a hydro-electric dam, the more of a problem there is with the anodes dissolving.
Hope this helps.

How close is close?

I have one 12 miles upstream and one 7 down.

 

[bamadave]

Re: Anode Life in Fresh Water?

I don't know how close you have to be. I live 1.5 miles from one and I have to replace the annodes every 2 or 3 years.