Hanging The Fish Zinc In The Marina Trick

[rebel heart]

Any solid thoughts on this? I've seen folks doing it here and there and especially when hopping into a new marina I'd rather burn up a disposable zinc than something more critical like one of my rudder strap zincs.

[Lancerbye]

Common practice here. I connect mine to the backstay chainplate as it is bonded to the common bond point. Saves my shaft zincs.

[GordMay]

Originally Posted by Lancerbye

Common practice here. I connect mine to the backstay chainplate as it is bonded to the common bond point. Saves my shaft zincs.

Indeed.
To complete the electrical circuit, the portable zinc must be electrically connected to the items they are intended to protect.

[rebel heart]

Originally Posted by GordMay

Indeed.
To complete the electrical circuit, the portable zinc must be electrically connected to the items they are intended to protect.

Is there a preferred model? I've seen guys rocking a big fish version.

[fstbttms]

A zinc is a zinc is a zinc. Ain't nothin' special about the guppy. Remember that it is possible to over-zinc. Arbitrarily adding anodes when there may not be a problem necessitating them can be a bad idea.

[Matt sachs]

What problems are created with to many zincs?

[fstbttms]

Originally Posted by Matt sachs

What problems are created with to many zincs?

For one thing, you can create a "burn-back" of the anti fouling paint around metal fittings on the hull.

[Matt sachs]

Good to know. I have 2 on the rudder 2 on the keel near the prop shaft, and 2 on the keel near the leading edge. How dose one determine where they should be?

[fstbttms]

Originally Posted by Matt sachs

Good to know. I have 2 on the rudder 2 on the keel near the prop shaft, and 2 on the keel near the leading edge. How dose one determine where they should be?

Underwater metal parts needing corrosion protection should be electrically bonded to an anode. This typically determines where anodes should be located.

You have nothing protecting your shaft & prop? Also, are you in freshwater?

[S/V Illusion]

Originally Posted by Matt sachs

What problems are created with to many zincs?

Every time you add a zinc, you are effectively adding a battery albeit small. Too many is counterproductive as the 'batter' becomes stronger creating problems where none previously existed.

Too many people connect a guppy zinc to the chainplates thinking everything is interconnected. On it's face, that is true but fails to consider all the connections between the chainplate and what the guppy is intended to protect. Every connection creates a resistance decreasing the efficacy of the guppy.

although difficult, it is best to ensure minimal or no connections. The wire itself has an inherent resistance so you want the shortest cleanest path.

[Cheechako]

Quite a few people do it up here inthe PNW. Seems to work great for those is marinas that make metal disappear fast!

[Matt sachs]

Originally Posted by fstbttms

Underwater metal parts needing corrosion protection should be electrically bonded to an anode. This typically determines where anodes should be located.

You have nothing protecting your shaft & prop? Also, are you in freshwater?

The boat is on stands for the refit. I plan to use it in both fresh and salt. The prop shaft is 44mm stainless, the zincs are near the shaft, but electrically its a long way from the zinc thru the hull to the engine and tranny and then to the shaft. The cutlass is rubber lined so I would guess it acts as an insulator between the shaft and shaft log/ hull. Am I over thinking this? Should the zinc be on the shaft?

[noelex 77]

Originally Posted by Matt sachs

The boat is on stands for the refit. I plan to use it in both fresh and salt. The prop shaft is 44mm stainless, the zincs are near the shaft, but electrically its a long way from the zinc thru the hull to the engine and tranny and then to the shaft. The cutlass is rubber lined so I would guess it acts as an insulator between the shaft and shaft log/ hull. Am I over thinking this? Should the zinc be on the shaft?

Be careful with zinc in fresh water. Zinc quickly develops a coating in fresh water that prevents it working even when you go back to salt water.
You can sand the the zinc and restore is conductivity, but this means a dive.
An aluminium anode may be a better choice for your mixed salt/fresh water use.

[Cheechako]

Originally Posted by Matt sachs

The boat is on stands for the refit. I plan to use it in both fresh and salt. The prop shaft is 44mm stainless, the zincs are near the shaft, but electrically its a long way from the zinc thru the hull to the engine and tranny and then to the shaft. The cutlass is rubber lined so I would guess it acts as an insulator between the shaft and shaft log/ hull. Am I over thinking this? Should the zinc be on the shaft?

Yes, you should have a zinc on the shaft or the prop if setup that way.

[fstbttms]

Originally Posted by noelex 77

Be careful with zinc in fresh water. Zinc quickly develops a coating in fresh water that prevents it working even when you go back to salt water.
You can sand the the zinc and restore is conductivity, but this means a dive.
An aluminium anode may be a better choice for your mixed salt/fresh water use.