zinc plated copper sleeve on a stainless steel wire rope in salt water -- should I risk it?

L

Lord Gothington

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Nov 17, 2019
15
Tartan 27 Yawl Chicago
I am replacing the pennant cable on my Tartan 27 centerboard. Tartan sent me a 1/8"-7x19 stainless steel wire rope and a zinc plated copper sleeve to crimp onto the end. That end will be submerged in salt water pretty much all the time for a year, and then in freshwater after that.

According to the Tartan website, the replacement cable now ships with a stainless steel sleeve. Is it a bad omen that they switched from zinc to stainless?

It seems to me that going all stainless steel is going to be safer from a galvanic corrosion point of view. Unfortunately, I only have access to a crimping tool for zinc and aluminum sleeves. I estimate the pennant cable will need to be replaced every 5-10 years.

Does it seem worthwhile to spend the extra time and money to find someone who can crimp a stainless steel sleeve? Or is that overkill and I should expect the zinc plated copper fitting to last longer than the expected service life of the wire rope? I know that zinc plated copper on stainless steel is common in the standing rigging, but this crimp will be constantly submerged in saltwater.

I know enough to know there could be a problem here, but lack the real world experience to tell me if it will actually be a problem.

Thanks!
 
capta

capta

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Jun 4, 2009
4,905
Pearson 530 Admiralty Bay, Bequia SVG
I can't imagine why they would ship you a zinc plated copper sleeve. Personally, I'd probably go with a lead sleeve instead of taking a chance that the SS sleeve might be 304 or a lesser grade of SS. If they sent you a zinc plated copper sleeve for a sea water application, then they most likely won't send you a 316 sleeve.
 
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Will Gilmore

Will Gilmore

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Oct 19, 2017
7,936
O'Day Mariner 19 Littleton, NH
What's the environment where you keep your boat? Besides it being in salt water, are you on a ball or in a slip? Do you plug in and run electric or do your closest neighbors? I understand electrolysis to really be an issue when there is a charge present. Sitting on a mooring where you are not connected or between a charge and ground isn't usually a problem. Since the Tartan 27 is a centerboarder, it sounds like the designer was expecting the boat to sit on a trailer, rather than in a marina.

My recommendation, since you are asking the question, is get the s.s. It is worth the piece of mind, if nothing else. How much extra cost is it?

Capta makes a point.

-Will (Dragonfly)
 
rgranger

rgranger

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Jan 19, 2010
12,553
Hobie 16 & Rhodes 22 Skeeter Charleston
Will Gilmore

Will Gilmore

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Oct 19, 2017
7,936
O'Day Mariner 19 Littleton, NH
rgranger said:
Send it back with a "no thanks" note... tell them you found what you need on Amazon..

Muzata Cable Railing Kit, Picture Hanging, T316 1/8" Stainless Steel Cable 33Ft with 50PCS Aluminum Crimping Sleeves and 10PCS Stainless Steel Thimble - - Amazon.com

Muzata Cable Railing Kit, Picture Hanging, T316 1/8" Stainless Steel Cable 33Ft with 50PCS Aluminum Crimping Sleeves and 10PCS Stainless Steel Thimble - - Amazon.com
www.amazon.com
Click to expand
:laugh:
I'm sure that will get a response.

-Will (Dragonfly)
 
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JamesG161

JamesG161

SBO Weather and Forecasting Forum Jim & John
Feb 14, 2014
7,744
Hunter 430 Waveland, MS
Copper anything is not good in salt water, thus Bronze.
Jim...
 
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L

Lord Gothington

.
Nov 17, 2019
15
Tartan 27 Yawl Chicago
rgranger said:
Send it back with a "no thanks" note... tell them you found what you need on Amazon..
Click to expand
That kit has aluminum sleeves. My understanding of the chart in reply #2, is that Aluminum would be far more prone to galnavic corrosion than copper or zinc:

zinc plated copper sleeve on a stainless steel wire rope in salt water -- should I risk it?

I am replacing the pennant cable on my Tartan 27 centerboard. Tartan sent me a 1/8"-7x19 stainless steel wire rope and a zinc plated copper sleeve to crimp onto the end. That end will be submerged in salt water pretty much all the time for a year, and then in freshwater after that. According...
forums.sailboatowners.com

Or do I not understand that chart?
 
Last edited:
rgranger

rgranger

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Jan 19, 2010
12,553
Hobie 16 & Rhodes 22 Skeeter Charleston
Right.... you probably want something like this... or two or three of these.

1580945697755.png
 
Davidasailor26

Davidasailor26

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May 17, 2004
5,540
Beneteau Oceanis 37 Havre de Grace
Lord Gothington said:
That kit has aluminum sleeves. My understanding of the chart in reply #2, is that Aluminum would be far more prone to galnavic corrosion than copper or zinc:

zinc plated copper sleeve on a stainless steel wire rope in salt water -- should I risk it?

I am replacing the pennant cable on my Tartan 27 centerboard. Tartan sent me a 1/8"-7x19 stainless steel wire rope and a zinc plated copper sleeve to crimp onto the end. That end will be submerged in salt water pretty much all the time for a year, and then in freshwater after that. According...
forums.sailboatowners.com

Or do I not understand that chart?
Click to expand
The thing about aluminum is that although it’s not very noble, its oxide is hard and generally impermeable. So as it corrodes it quickly forms its own protective layer.

Edit: At least the protective layer applies for oxidation in air. Not sure about in sea water.
 
L

Lord Gothington

.
Nov 17, 2019
15
Tartan 27 Yawl Chicago
Will Gilmore said:
What's the environment where you keep your boat? Besides it being in salt water, are you on a ball or in a slip? Do you plug in and run electric or do your closest neighbors? I understand electrolysis to really be an issue when there is a charge present. Sitting on a mooring where you are not connected or between a charge and ground isn't usually a problem. Since the Tartan 27 is a centerboarder, it sounds like the designer was expecting the boat to sit on a trailer, rather than in a marina.
Click to expand
The Tartan 27 is a heavy displacement bluewater sailing yacht. A few people trailer them for cross-country moves, though it is technically 1" to wide to be street legal with out a special permit. But a vast majority are moored.

In the past I was on a mooring can in freshwater. But for at least the next 9 months I will be spending a few days per week in a slip in salt water. After that I'll be in a slip in freshwater most days.

That said, I am not sure that your understanding of electrolysis is quite correct. The core elements you need for electrolysis are two galvanically dissimilar metals which are electrically connected and submerged in an electrolyte. That creates a battery which results in the metal which is lower on the galvanic scale becoming depleted.

One reason this problem occurs a lot in slips is that the boats become electrically connected through the shore power connection creating a circuit between the dissimilar metals on the neighboring boats. The solutions to this problem involve breaking that connection. For example, if your power system uses an isolation transformer, then the two systems are no longer directly connected. The corrosion only occurs due to the flow of DC current, but only AC current can flow through a transformer.

But, looking at the initial conditions -- dissimilar metals electrically connected and submerged in an electrolyte -- it is clear that you can easily create those conditions on your own boat with no shore power. For example, if I had a zinc and copper sleeve on a stainless steel wire in salt water.

Will Gilmore said:
My recommendation, since you are asking the question, is get the s.s. It is worth the piece of mind, if nothing else. How much extra cost is it?
Click to expand
I am still getting quotes. The price of the sleeves is inconsequential. With the zinc plated copper sleeves I can use the swaging tool at West Marine for free. With the stainless steel sleeves I must either buy a $200 tool or pay a local rigger to do it for me. Paying a local rigger to do anything -- no matter how simple -- doesn't sound cheap.

I have a tendency to over-engineer things. So, I wanted to do a sanity check and make sure it was actually worth the extra costs to get stainless steel instead of zinc plated copper. It is potentially 10x the cost once labor is factored in.
 
PaulK

PaulK

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Dec 1, 2009
1,353
Sabre 402 Southport, CT
Where does the sleeve end up when the board is raised? Is it submerged or above the waterline? If it ends up above the waterline, electrolysis & corrosion issues might be less than people think.
 
L

Lord Gothington

.
Nov 17, 2019
15
Tartan 27 Yawl Chicago
PaulK said:
Where does the sleeve end up when the board is raised? Is it submerged or above the waterline? If it ends up above the waterline, electrolysis & corrosion issues might be less than people think.
Click to expand
The sleeve will be submerged 100% of the time. It does not matter whether the board is raised or lowered.
 
L

Lord Gothington

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Nov 17, 2019
15
Tartan 27 Yawl Chicago
Brian D said:
Unless one is using it for SSB radio. :laugh:
Click to expand
That is an whole other can of worms I will eventually open. My boat has an external lead keel. I am curious how well it would work as an RF ground, and if that would somehow cause my keel to fall off :) But I am not going to start down that path until many moons from now.
 
Brian D

Brian D

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Feb 17, 2006
5,274
Lancer 27PS MCB Camp Pendleton KF6BL
Lord Gothington said:
That is an whole other can of worms I will eventually open. My boat has an external lead keel. I am curious how well it would work as an RF ground, and if that would somehow cause my keel to fall off :) But I am not going to start down that path until many moons from now.
Click to expand
There is a Forum for SSB/Ham Radio operations on boats. You can ask that question there so we do not go way off topic here.
 
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