Annode Question

[barthel]

Hi All,

I apologize in advance if this has been covered to death, but I've been searching and can't quite find the answer I'm looking for.

The wife and I just bought a '98 Stingray 180RS with a Merc Alpha 1 Gen II sterndrive. The zincs don't look TOO bad, but as part of my anal retentive run-through on the boat I thought I would replace them. I read enough to get the basics, zinc for salt or brackish, magnesium for fresh BUT;

What if the boat may see both? Is running magnesium annodes in salt water a problem? What about zincs in fresh? Our intended usage for the boat will be 99% fresh water (local lakes and the Colorado River) but may take it into the ocean on occasion.

Any advise?

 

[bruceb58]

Re: Annode Question

Are you keeping your boat in the water for any length of time? If you are just putting it in for daily use, don't bother changing then unless they are already eaten away.

 

[tpenfield]

Re: Annode Question

Go with your 99% and get the anodes for fresh water. Since your salt water use is planned to be so limited, not having the ideal anodes for salt will be negligible.

 

[bruceb58]

Re: Annode Question

And by the way, the anodes you want for salt water are actually an aluminum alloy and not zinc. You do not want magnesium in salt water as Mercruiser specifically says NOT to use them in salt water.

Stick with what you already have on your boat. If your boat hasn't already been moored for lengthly times in salt water, yours are probably perfectly fine.

 

[TilliamWe]

Re: Annode Question

Is running magnesium annodes in salt water a problem?

It's not a problem if you are just going to be in the salt for the day. But if you are going to keep it in over night or for a week at a time, they will get eaten away QUICKLY. Still not a problem, except that the "Freshwater Only" anodes cost twice as much.
But if I was in your situation, and I was keeping it in freshwater all the time, I'd use the Freshwater only. If this boat is a trailered boat, use the standard aluminum anodes, and save your money.

 

[barthel]

Re: Annode Question

The boat is trailered, and if it did go in the ocean it would in all likelihood be only for the day. The longest it would ever be in the water continually would be about 4 days in the summer when we go to the Sacramento Delta, or in Havasu. Mostly I think it will be coming out every night.

So, that being said, should I look at the aluminum ones rather then the magnesium? I'm not exactly sure what's on there now but I'm thinking they're zinc due to the corrosion pattern (white calcification on the outside), but the PO didn't know for sure as he had never changed them.

 

[bruceb58]

Re: Annode Question

Leave them on there. They are fine as is. You only have to worry about them if you are leaving your boat in the water months at a time.

 

[Ned L]

Re: Annode Question

As has been said, if the majority of their mass is still there then leave them alone. You are just wasting money by changing them (unless you just want them pretty).

 

[TilliamWe]

Re: Annode Question

As has been said, if the majority of their mass is still there then leave them alone. You are just wasting money by changing them (unless you just want them pretty).

Yep. Over 50% worn away = replace. 50% or more remaining = GO BOATING!

 

[barthel]

Re: Annode Question

10-4, thanks for the info gents!

Not worried about them being pretty, it's my first power boat and I'm just trying to figure out what to worry about and what not to. =)

 

[BillP]

Re: Annode Question

Yep. Over 50% worn away = replace. 50% or more remaining = GO BOATING!

That only applies (unless you want to waste $$$) to boats that are kept in the water and can't make the next haul out before the anode is totally wasted away...leaving no protection.