Replacing stainless steel centerboard control cable with dyneema?

[autumnbreeze27]

Our centerboard is raised or lowered by a control cable. The issue we have is the stainless steel cable connects to the board via a swaged eye that fails after 1.5-2 years due to corrosion.

I was talking with a cruising buddy and he suggested a stainless eye terminal like this:
Indital Stainless Steel Eye Terminal to Crimp Wire Rope 13/64" Dia. - Wire Ropes & Accessories

My other thought was to replace it with something synthetic like dyneema and just attach it with a bowline. Would that work, or am I just trading one kind of maintenance for another?

[Dave852]

A splice will be much stronger than a bowline and take up less room. Having said that you don't need a lot of strength for that application. As long as there's not to much chafe involved I like it.
I am using it to lift a 22' boat with a 150 hp, have not got around to a splice yet.


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[Cheechako]

Not sure , but I think you will need more than a bowline for Dyneema as it's slippery right? I could see a swaged fitting being problematic for that use. I wonder if a spliced eye in braided wire would be less corrosion prone and not have the "hard spot' typical of a swaged eye at the fitting /cable interface?

[belizesailor]

Agree you want a spliced eye and not a knot in slippery Dyneema.

I helped a neighbor with a similar project last year. His boat had a separate dedicated power winch for his dinghy lift. It was rigged with line which failed. He replaced it with Dyneema using splices. Easy project.

Good news: hollow braid Dyneema is easy to splice, but the splice needs to very long so plan accordingly.

[roverhi]

Replaced my CB cable with a dyneema line. It has a spliced eye with thimble for connecting to board with a shackle. The line has worked without any issues except the tail of the splice is so long that it jambs in the turning block in the bilge and leaves the board peeking out a couple of inches below the keel. A knot would have allowed the board to fully retract. Will try that the next time the boat is hauled but stitch the knot so it can't untie itself and see if an inch or two can be gained eliminating the shackle and fastening the line directly to the board.

If I understand the problem with these high strength lines is they are slippery but not so slippery that a knot won't hold. The problem with knots in the line, other than it reduces the strength of the line, but cyclic loads. When tension is put on the knot and then relaxed , the knot loosens with each cycle. When tension is applied again the knot slips a little until eventually the tail pulls through. Can live with the loss of strength as the line is grossly over strength for the load but have a fond desire not to have it untie itself and leave the board hanging. Stitching the knot should prevent that.

Quit using a bowline on my lines and have gone to a Buntline hitch. Supposedly works better on these high tech synthetics. Also understand there is another knot that is more compatible with these lines. Perhaps someone else know what that is. Haven't had any problems with the buntline hitch holding on dacron jacketed dyneema lines. Don't use shackles on any of my halyards or sheets and haven't had any problems including the run to Hawaii.

[sanibel sailor]

Replaced my stainless steel cable with dyneema 3/16". The problem was not corrosion but as I later found out the Nicopress swerve would kink where entered the pulley. I have no complaints about the dyneema. A hitch will work better than a splice because you can dive on the boat every year or so cut off a few inches and retired. I used an anchor band with a couple half inches and then send stuff the Bitterend with a wire tie. inches and retired. I used an anchor band with a couple half hitches and then seized the bitter end with a wire tie.

[autumnbreeze27]

Thanks all for the info!

[Chkm8]

Hi Dyneema works use a sailors stainless thimble with a full locking Brumble splice short tuck and Stitch 1 inch after Brumble. It does not wear this way and can carry an amazing load Paul

[Frankly]

My SS CB pendant was replaced after 8 years out an abundance of caution. Old wire and eye were fine after I pulled them out. Boat is in salt water 365 days a year but the pendant is connected to the bonding system and I am religious about replacing zincs.

Be sure that the Nicopress is copper. Big box store Aluminum would be short lived in this application. Used 316 SS wire and thimble and plated copper sleeve for my replacement. Plan on the next change out in 2023.

Frank

[estarzinger]

Just FYI . . . . Here is the best knot for the application . . . http://www.bethandevans.com/pdf/estar.pdf

Highest strength/no slip.

The best splice for the application would be a 5x Brummell with no bury (to minimize length). This would be stronger than the above knot, but the extra strength is probably not needed, and it is a bit longer and a bit more complex to construct.