Looking at Wire Rigging

I know I focus a lot on Synthetic Standing Rigging on this blog, but there is one important point to make about all rigging: They work until they fail.

Replacing steel standing rigging to synthetic standing rigging is a waste of money. Rigging is expensive and while synthetic standing rigging is cheaper than steel standing rigging, the cheapest standing rigging is the one you already have!

This is why I feel it is important to know how to look at your steel standing rigging to better determine when it needs replacing. Once your rigging needs replacing, that is when deciding what material to go with makes monetary sense!

This is what your standard 1x19 Stainless Steel wire (304, 316, or 316L) should look like. All the strands are pretty, polished, and clean. There are no signs of corrosion or other problems with the wire. Dirt is a fact of life and should not be a cause for alarm. Some boat owners go above and beyond to keep dirt out of every surface of their yachts; and while this is a positive trait in someone selling you a boat, it is also not practical or realistic to keep every inch of wire on a sailboat clean and free of dirt or debris!

Now we start to see problems develop. This wire is still in adequate condition for now, but its end is approaching. This is when you should begin saving up for the cost of replacing your rigging and deciding what material you wish to replace your standing rigging with!

Are you going to replace your rigging yourself or are you going to pay a rigger to do it? If you are going to pay someone, will they come to your boat or do you need to take your boat to the yard where they work? This would also be a good time to start collecting estimates from different riggers that way you know where you will be going when the end of the line finally comes.

When your rigging looks like this, you can still sail on it, but you need to keep a close eye on your rigging because it is dying. It is not dead yet, but it will be getting there!

This is what wire looks like when it is on its last leg. You can see many spots where rust is occurring. The strands have lost their luster and appear dull and tarnished. Rust spots are less the rare occurrence and more the norm, as almost each visible strand has multiple rust spots on it.

It is important to note the strict difference between rust staining and rusting metal. If you take perfectly fine stainless steel and rest it up against a rusting piece of metal, the iron oxide from the rusting metal will stain your perfectly fine stainless steel. This means that if you have a low quality piece of metal attached to your rigging and it begins to rust, the metal of the stay near this will develop a rust color. Rust stains polish off and the wire will go back to looking like new.

If the wire itself is rusting, there is no amount of polishing that can be done to remove all the rust and restore the original luster of the wire. When the stay itself is rusting, that is when it is at the end of its lifespan.

When the stay begins to corrode like this, it should be replaced promptly. Yes, you can still sail in light conditions with it as it has now “failed” yet, but it will soon fail and should be replaced.

Failed rigging is when it actually breaks, and while you can sail with your rigging until that occurs, the problem is that when a failure occurs during use, the repairs tend to be rather costly!

Imagine for a moment that you have your sailboat sitting in the slip and the port cap shroud begins to develop significant corrosion. At this point, your sailboat is sitting in the slip with the mast standing straight and tall. Nothing has broken or given way yet.

You make arrangements and either replace the stay yourself or hire a rigger to replace the stay for you. Then you go sailing with your new stay and nothing happens.

Now lets imagine the same situation but instead of replacing the stay when it was dying, you wait for the stay to fully die. You are sailing along on a close reach on starboard tack. The spray is coming over the bow and you are heeling well to leeward. Everything is wonderful and then you tack. Now all that load is on the corroding port cap shroud and the failing stay finally fails. The wires break and the mast becomes unsupported. The cap shroud had broken and the only think holding the mast up in the air are the lower shrouds! The force of the wind on the main and headsail pull harshly against the top of the mast which is no longer being supported by the port cap shroud and the mast begins to bend. The mast bends further and further causing the sails to become baggy and hold even more wind, and pulling even harder on the unsupported mast until it buckles at the lower spreader attachment.

Now you have a broken mast as well as a failed port cap shroud!

This is why you want to replace your stays when they are failing instead of waiting for them to fail.

Galvanic Corrosion on your Mast

Galvanic Corrosion is a silent killer of your wallet. It starts off so quietly and slow, barely noticed until it develops into a very expensive problem that will cripple your aluminum mast!

This mast has been pulled for winter storage of the yacht. The spreaders are neatly stowed inside the hollow spar for safe keeping. The bottom of the mast where it rests over the mast step is bubbling up with galvanic corrosion and this means that the mast is slowly but surely dying right at the base!

In a situation like this, the mast base will eventually become too weak to support the loads it is subjected to while sailing. The mast will ideally crumble down onto the mast step and all the rigging will go slack as the mast instantly becomes a few inches shorter. We all know that nothing on a sailboat breaks ideally, and instead the good aluminum just above the step and bad aluminum will slip off to the side of the step and the whole mast will come toppling down in a horrific and catastrophic failure of the rig!

For comparison, this is a perfect mast with absolutely no problems occurring at the step! Now, why is this happening to the first mast and not to this mast? Well, to put it simply, it’s because this mast is fully protected by paint and other insulating layers. There is no contact between the aluminum of the spar and any other metals, hence no cause for galvanic corrosion. The mast above must have a tiny scrape in the paint or contamination with a different metal around the mast step because the damage is localized only to the step of the mast and no further.

The damaged mast doesn’t need to be replaced, the solution is actually quite simple. The affected portion of the spar should be stripped bare and evaluated. If the corrosion is too extreme, the section is simply cut off and the mast made shorter. If the corrosion is minimal, a new coating of paint is in order to isolate the metal and protect it from further and future corrosion. Lanolin can also be used around the mast step to act as an insulator and protect against galvanic corrosion where the mast meets the step.

This mast, however is suffering from much more crippling damage.

You can see the paint bubbling up around the screw holes. This is caused by galvanic corrosion between the stainless steel screws and the aluminum spar. Apparently, no isolator was used, and if one was used, it has failed as isolating the two dissimilar metals leading to galvanic corrosion of the aluminum. The problem with this is the location.

Unlike with the other mast where the damage was located at the bottom of the spar, this corrosion is occurring on the side of the mast. If left unchecked, the side will form a hole and severely weaken the mast. This area is also in one of the highest stressed areas of the spar: The head.

All the forces of the sails, halyards, and rigging culminate at the head of the mast in the area of the truck (where all the welds are) and this is exactly where those little screws are bubbling away the aluminum of the spar. Eventually, the mast will break and make a big mess of the boat below it!

The corrosion still looks minimal and the screws do not appear overly critical. They could easily be removed and the area cleaned and protected. If they are necessary, then they can be coated in lanolin and reinstalled, paying close attention to the area in future rig inspections for any sign of renewed corrosion in the area.

If these small bubbling corrosion points are left unchecked, they can lead to very dramatic and costly results. Be sure to check any fasteners in the mast with a close eye and hold the area to the utmost standards of perfection. When it comes to your spar, there is no “good enough”!

Finding Crevice Corrosion

Our staysail setup involves three stays:

• the inner forestay

• two check stays

All of these stays attach 2/3rds up the mast, between the spreader and the cap shrouds. They kind of serve the purpose of a second spreader in terms of mast rigidity as it is a second attachment point, but without the added complexity of intermediate stays.

When we sail in heavy weather, we reef down to this point on the mast by flying only our staysail and double reefed mainsail. This keeps the forces lower on the mast and closer to the center of the boat, providing us with a balanced sail plan and comfort in uncomfortable times.

Having synthetic standing rigging means that our stays are immune to corrosion problems. Most of the end fittings that connect our stay to the mast are bronze, but these three toggles to the inner forestay area were all stainless steel.

Can you spot the crevice corrosion?

I spotted this flaw in the Azores right before we were leaving during my routine aloft inspection of the rig. We decided to go because in the Azores, everything is Metric and trying to get Imperial sizes there is a nightmare!

The corrosion was in the length of the metal, not across it. This meant that it was weakened but not completely broken.

We sailed on with the stress on mind that our toggles could fail and sailed about 1800 miles to reach mainland Portugal, where we soon hopped on a plane to fly back to the states to visit family.

The plan was to bring easy to buy bronze toggles back with us from the States rather than to mess with all the red tape to import “yacht parts” into Portugal.

The Best Inhibitor of Galvanic Corrosion

In the world of advanced chemical compounds, it seems that the best solution to a simple problem like galvanic corrosion would be a synthetic concoction. The truth is, all modern chemicals are compared to the best solution to the problem: lanolin.

Lanolin, sold as Lanocote, is removed from sheep’s wool. The lanolin is separated from the wool and bottled up into small jars. This agent is natural and safe to use without gloves, and will not react with your skin!

It works great at keeping water out and dissimilar metals separated which then prevents any galvanic issues.

I personally use this anytime I have bronze and stainless steel touching, and an extra thick layer anytime I am mixing stainless fasteners with aluminum fittings. If you don’t use lanolin, or one of the other more expensive materials, you will quickly see bubbles form in the aluminum adjacent to the stainless steel fastener.

Lanolin is easy to use and good to keep in the boat. Best of all, it lasts a long time. I have been dipping into my same pot for the past 5 years and it is still full enough that I don’t need to think about buying more of it anytime soon!

2 Year Headstay Inspection

Wisdom, our 1968 Morgan 45 was re-rigged with synthetic standing rigging back in 2015. The headstay has endured use, abuse, and a lot of weather over these two years. Our headstay's deadeye got severely damaged by our anchor and needed to be replaced, giving us a wonderful opportunity to evaluate how the stay is holding up at the bow.​

The bow is known to be the harshest place on a yacht for rigging. Every single wave that splashes up will wet the stem and the lower part of the headstay in a fine misting of salty moisture. This mist will work its way into the tiniest nooks and crannies in your headstay, causing devastating corrosion from the inside out.​

To make life for your stem fittings even harder, being up at the tip of the bow, they are often ignored and forgotten, as the rest of the boat gets cleaned regularly, but the headstay might only get a quick splash with a hose.​

On most yachts, the headstay lives inside the furler, where it is forgotten and ignored until something breaks. On yachts with hank on sails, the headstay is easily inspected, but still neglected.​

Synthetic rigging prevails in these hardships, as the Dyneema fibers are made out of plastic and are immune to corrosion caused by moist salt spray. Let us see what lies beneath the surface of our headstay!​

Under all those wraps, you will find the true knot that holds the entire stay in tension: The Shroud Frapping Knot. This knot pinches and seizes the lashings together with such ferocity that even slippery Dyneema can not escape its hold.

This knot is tied while the tails of the lashings are under tension with the entire tensioning system. While the lashings are tight and under load, the Shroud Frapping Knot pinches them in place, allowing you to remove the tensioning lines without losing any tension in the headstay. 

This relatively simple knot can be a bit time consuming to tie, taking me close to 20 minutes, but it will hold steadfast for years, never yielding nor giving way as you sail. 

On stays that will require a significant amount of tension, it is best to use oversized thimbles as they will accommodate more wraps with the lashings, giving you significantly greater mechanical advantage to properly tension the stay. They also provide a wider radius turn which imparts less stress on the fibers of the lashings.

With the tension removed and the lashings untied, you can see the inside of the eye splice at the end of the stay. The fibers have flattened out as they have been pressed into the thimble for two years. There is some slight corrosion staining that appears on the eye splice, and this is from slight surface rusting that occurred on the stainless steel thimble. 316 Stainless Steel is famed for being corrosion resistant, yet in two years on the bow, it has begun to corrode in places that are not visible to external inspection. Imagine if this were a steel headstay with steel fittings swaged together up here. Corrosion would have already set in and it would be a countdown until something failed in a catastrophic manner. 

Synthetic standing rigging is immune to these sorts of problems and the steel components utilized are small and easy to inspect, making their impact on the entire situation much less grave.