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Old 03-10-2012
jamesnewsome jamesnewsome is offline
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Re: Seafarer 24 swing keel, keel pivot? Sailing qualities?

From a couple previous posts there seems to be some skepticism concerning my comment about the SS cable "parting," apparently due to electrolysis. This was not a second-hand report. It happened to me in 2000 when I launched my Seafarer 29.' ROMA had been in the water about a month when I noticed the loose SS cable on the winch in the cockpit. When I pulled it up the cable appeared to be "parted" about mid-length as if I had pulled from each end until it broke. Imagine a cheap cotton rope that you can pull apart.

Since this cable was installed by the previous owner prior to my purchase I assumed it was just a bad cable or not a good quality SS. I had a diver coming the same day to clean the bottom so he disconnected the other end and I took the broken SS cable to West Marine and had it send to their rigging shop to make another one. I also made sure they knew how it was going to be used.

After installing the new cable I thought I was home free until about a month later the same thing happened. I started reading and asking questions and the consensus was that the fine strands of the SS cable were subject to natural electrolysis since Stainless Steel is actually an alloy and thus contains metals of different nobility. The fine strands of the SS cable apparently allow the electrolysis process to accelerate.

I was also concerned about stray electricity around my boat so I reported the issue to the marina management and they promptly had their electrician check out the area and found no problem.

When I took the second SS cable back to W. Marine their rigging shop suggested Kevlar, which is actually stronger than SS for the same size line. 11 years later the Kevlar cable is still on ROMA and performing well. I have the bottom cleaned every month to 6 weeks, and I've cleaned it many times myself. Yes, barnacles and slim sometimes do grow on the Kevlar cable but can be removed by rubbing with my glove.

There is no sign of any abrasive wear on the Kevlar cable. Interestingly, try to cut a piece of Kevlar with a knife or wire cutters. You will find it difficult to cut even a small stand. After all, this is the material used to make bullet proof vest so the fibers are extremely strong and do not easily cut. Wonder what would happen to a bullet proof jacket made of SS cables?

When I had ROMA pulled a couple years ago I had asked the boatyard to replace the Kevlar cable, but they forgot. So that original Kevlar is still on the boat. I do occasionally have to winch up the keel, and I have a chance to inspect the line on the drum. Other than being a little stained it still looks fine.

The bottom line is that I do not completely understand the science or the exact nature of the issue that took place with the two SS cables. I do, however, completely understand the reality of the situation as it occurred on my boat, and I try to share this experience any time the subject come up.

Unfortunately, there have been several documented cases of weighted keels tearing the bottom out of sailboats because the keel cable broke. Your guess is as good as mine about whether electrolysis was the cause or there was another issue.

Since I had my original Kevlar cable made by West Marine, the newer Amsteel Blue Synthetic lines have come to market. And they have superior ratings over SS or Kevlar, so next time I'll probably switch to this material.

I hope this was helpful to anyone interested.
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