Refurbishing a Zinc Anode

[Kenomac]

Maybe I should have clarified things a little more. The anode pictured came off after two years, but the boat had been in the water for a total of nine months, but during the time in the water... never in a marina. It was changed for a new anode and I ground off the crud from the old anode. I have a total of three... one on the boat and the two you see pictured.

Now the boat sits in fresh water seven months per year/salt water five months and the crusty stuff gets removed several times per year.

[savoir]

Originally Posted by SVRocinante

This brings up another question that's been bothering me.
I've met several people that hang a "Zinc" from a line off their boat.

Once again, having only the most basic understanding of how the zinc is supposed to do it's job, I don't understand what possible good it can do to dangle a zinc that is not somehow "connected" to the boat.

info?

That is only necessary for metal hulled boats. The other end of the wire is clipped to the hull. On a fiberglass hull there is no point.

[newhaul]

Originally Posted by savoir

That is only necessary for metal hulled boats. The other end of the wire is clipped to the hull. On a fiberglass hull there is no point.

Not exactly true. My frp boat does benefit greatly from my setup. The only other zinc is the prop nut zinc . as I stated earlier my entire vessels bonding system is connected to the bar zinc I hang over the side when in a marina.

[waterman46]

Replace zincs when mechanically unsound ie. ready to fall off. Use only new, not recast. Grinding to a flat surface only serves to reduce available surface area.

[boatpoker]

Originally Posted by buzzstar

Someone else said it, but differently. There are courses for horses, and horses for courses. There are anodes (zincs usually) for salt water, brackish water, and even fresh water. I recall prior discussions, in some depth, on CF, and strongly recommend that you searchers and questioners check there. It can save you a lot of money and grief.

No horses, no courses. This is quite simple and well established science and anyone with a history in the marine business has seen the very expensive ramifications of getting it wrong.

PS. Zinc does NOT work in fresh water, it's voltage potential is simply too low, not opinion, simply fact.

[Kenomac]

Originally Posted by boatpoker

No horses, no courses. This is quite simple and well established science and anyone with a history in the marine business has seen the very expensive ramifications of getting it wrong.

PS. Zinc does NOT work in fresh water, it's voltage potential is simply too low, not opinion, simply fact.

Marina is in fresh water, the sea is six miles away in salt water. What would you suggest we do... change our anodes from aluminium to zinc and back everytime we head out?

[boatpoker]

Originally Posted by Kenomac

Marina is in fresh water, the sea is six miles away in salt water. What would you suggest we do... change our anodes from aluminium to zinc and back everytime we head out?

Just stick with aluminum, it works in all waters.
Several years ago Mercury Marine realized this wisdom and now ships all new drives with aluminum anodes whereas they were previously shipped with zinc anodes.

[Kenomac]

Originally Posted by boatpoker

Just stick with alauminum, it works in all waters.

How long does it last in salt water compared to zinc?

[boatpoker]

Originally Posted by Kenomac

How long does it last in salt water compared to zinc?

some say it lasts longer, I'm not so sure ... too many variables.

[Kenomac]

Originally Posted by boatpoker

some say it lasts longer, I'm not so sure ... too many variables.

Thanks

[GordMay]

Originally Posted by boatpoker

some say it lasts longer, I'm not so sure ... too many variables.

Aluminum provides more protection (higher voltage potential), and lasts longer* than does zinc.
* Al lasts about 1.3 to 1.5 times longer than Zn (Different manufacturers quote different ranges).

[fstbttms]

Originally Posted by boatpoker

Just stick with aluminum, it works in all waters.

Magnesium anodes only for fresh water.

[savoir]

Originally Posted by newhaul

Not exactly true. My frp boat does benefit greatly from my setup. The only other zinc is the prop nut zinc . as I stated earlier my entire vessels bonding system is connected to the bar zinc I hang over the side when in a marina.

It would only benefit if the other end of the wire was attached to the engine block or gearbox.

[newhaul]

Originally Posted by savoir

It would only benefit if the other end of the wire was attached to the engine block or gearbox.

Exactly . As I stated the entire bonding system is connected to the hanging zinc. ( the entire system includes the engine. )

[hellosailor]

"re-cast zincs to order."
A bespoke foundry pour. Ah, the mundane tasks that impose upon the hired help's time.
(G)

a64-
It isn't some mysterious gas that zinc gives off, it is simply the vaporized zinc itself. That is why steel scuba tanks are galvanized on the exterior--but never the interior. Zinc is toxic when inhaled, and dust or vapors will do just as nicely. Same thing with casting or grinding lead.

Now if the guy who invented the pop-up turkey baster button could only make something similar for anodes...Or a way to add in two LEDs, green means it is working, red means it needs replacing. Shouldn't be too hard to attach a light to the battery, right?