Someone, on a boating Facebook Page said that stainless rigging was very unpredictable. I assumed that he felt that you had no idea when it would fail.
So far, our stainless rigging has been predictable. It is 1×19 wire and we inspect every inch before any big passages, or once a year. We have found a broken strand on two such inspections.
We built our boat from the fiberglass, bare hull made by Bluewater Boats. She is a 38 foot cutter, about 45 feet overall. We rigged her with 1×19 304 stainless made by a prominent brand at the time. We know it was their wire because it came on a wooden spool branded with their name. However, in our considered opinion, the wire was clearly defective from the factory.
We launched in 1976, and sailed the boat a lot in the Puget Sound area as a shakedown. In September 1977, a month too late that year, we left for a two year trip to the South Pacific.
From Seattle down to Acapulco, out to the Marquesas, over to Tahiti and Bora-Bora, up to Hawaii, and then back to Vancouver Island and Seattle. Before each passage, which was about every six months, we inspected every inch of the rigging from a boatswain’s chair. As we were about to leave Hawaii, we discovered one strand broken, near the bottom CastLoc fitting on the head stay. We did not have roller furling at that time.
We had enough wire to replace one piece of rigging, but we were unsure as to what we were actually looking at. Was it really a problem with our wire, or was this just a bad joint when they were making that strand. There was no, ‘meat hook.’ All wires were exactly in place.
It is my understanding that wire rope is made by casting a bar of stainless, and then running it through rollers, to make it very long and skinny, and at some point, they start pulling it through dies made of industrial jewels. This makes it a little bit smaller each time it is pulled through a die. They keep passing it through smaller and smaller dies until it is the size they wish. To get a piece of wire to start to go through the die, you must squeeze down the end until it is smaller than the die, so it is fiddly when you start. You naturally want to avoid doing that if possible. And we thought that probably they but welded wires together so they only need to taper the point the minimum number of times. It becomes virtually a continuous process.
So, unless the weld is really perfectly done, it is slightly different and might be what had failed. As I said, the wire is one strand combined 19 times to make the 3/8 inch wire, so one broken strand only weakens it by reducing it to 18 strands. We thought that was strong enough since we felt we had a large safety factor in the wire. So, we decided to leave with everything as is, and keep a close eye on it during our passage. Every inch of the wire, except for that point, looked absolutely perfect.
But, we had a learning experience. I think it was a 23 day passage to Vancouver Island, with mostly light winds. When we were maybe 15 days into the passage we discovered another broken strand, very close to the first one. As I remember, by the time we got to Vancouver Island, we had three broken strands.
In our mind, we were almost home, and had a low risk of getting into any storms. We would just stay in port if the weather was bad, since we were now harbor hopping. So we elected to continue on. And it all went perfectly.
But, as soon as we got into our home marina and all settled, we contacted the company, because we felt that to have so many broken strands, only three years into the using of the wire, told us that something was wrong with the wire.
An engineer there, agreed with us completely, and transferred us over to talk to one of the bean counters about getting free replacement wire sent to us. Sadly, or perhaps happily, the bean counter would hear of no such thing. She said things like, how can we be certain that that is our wire?"
I said we still have the spool it came on, with your name branded on it. I’m pretty sure that at that point we still had the receipt. But, she would hear nothing of it, and I hung up angry.
Soon after, I was complaining to a friend, and they pointed out that if that company sells crummy wire, do you really want to use it even for free?
That seemed like a good point, so we bought 316 wire from a different major manufacturer. 316 is slightly weaker, but we felt that our rigging was larger than really necessary. We had chosen that for safety and offshore boat.
We used CastLoc fittings which are a stainless steel housing that you put the wire through and expand the end and then fill it with a special epoxy and metal powder mix. We felt that it was the safest possible rigging termination, and also the strongest possible. Anytime you tie a knot in rope, or make a splice, or terminate the end with some fancy gizmo, you make a weak spot. The actual rope is always stronger than where you attach something.
At that time we were told that elevators were only allowed to use spelter sockets. This is because, before the invention of CastLoc, they were the strongest and most reliable termination. And the CastLoc was really the same principle, just using epoxy in place of zinc.
But, one of the advantages of CastLoc was that you could carefully heat it up with a torch, just enough to soften the epoxy, and take it apart and reuse it. So, we did. It turns out that they are annoyingly difficult to get really clean. And after that one time we switched to Sta-Lok Terminals.
But, in taking the terminals apart, we had intimate knowledge of the quality of the wire. We found that the only damage was a few inches above the bottom CastLoc fittings on several different wires. On our rig we have 11 wires. As I recall half of them had broken strands, brittle strands, near the bottom, when we disassembled the rigging.
The original problem at the head stay, had some broken strands hidden inside the 1×19, and many of the wires were very brittle. By that I mean that healthy stainless steel rigging wire is very ductal. It is obviously stiff, but you can literally tie it in a knot and pull it relatively tight. I would think that you could take one strand of the wire and, fairly easily, wrap it around a 1/4" inch rod. Perhaps smaller.
However, these strands were more like a toothpick. You bent one slightly, and it snapped.
I was told a very long time ago that stainless steel, ‘work hardened’. By that I mean that as you bend it, back and forth, it gets harder, but more brittle. I think that’s what happened here. There was something wrong with the alloy, or how it did been handled during manufacture, that cause the wire to get more and more brittle, near the bottom fitting, as the wire flexed in normal use. And it doesn’t flex much.
I think we re-rigged in 1979, and the boat sailed to Alaska the summer of 1980. In 1981 we headed south to Mexico, and in 1988 we were in Panama, when we found another broken strand.
Having learned from our previous experience, we immediately replaced that piece of wire with our spare wire. And, re-rigged once we reached the United States.
I’m almost done.
While we were in Central America, someone gave us an article about Nitronic 50, a super stainless, that is more corrosion resistant than 316, but stronger than 304. We vowed to find some for our new rigging.
But it was not that simple. By the time we got to America, they had stopped making that wire in 1×19, and only made rod rigging from it.
I called the factory to see if anyone might still have enough wire in stock, and he calmly told me to submit a request for quote, and they would quote me for making custom wire.
I tried not to laugh, because I was just rigging one boat, and I assume that he needed an order for thousands of feet of wire to make it practical.
I mentioned that to him and he just repeated that we should request a quote and see what develops. I think he was doing me a favor.
A close friend was building a similar boat, and I told him about what I discovered and asked if he wanted to be included if I could find some of this Super Wire. He said that sounded wonderful if he could afford it. So, I sent in a quote for twice as much wire as I needed. This would be enough to rig my boat, and have a spare wire, and then I doubled it for the other boat.
Quite quickly they called back with a price, that was less expensive than the best price I had found for lower quality wire, buying it wholesale. We were very excited and said a giant, "YES!"
We install that wire in 1998 and have yet to have any problems with it whatsoever. During that time we had sailed from Texas to Turkey.
Crevice corrosion , particularly at the bottom of your s/s, prone to happen whenever it is deprived of oxygen. We seldom would use s/s wire on the ship. We did have some contractors insist on loading their own on our sampling winches.