“Years of life left in that…..”

Hmmm…. Ah….Yes…But surely, there’s years of life left in that yet?

At this time of year we occasionally have to have that difficult conversation with a customer who has brought their sails in for a winter overhaul. After another enjoyable season they look slightly dumbfounded when we look at the sails and suck air through our teeth. A bit like a new car sales man did once when I tried to trade in my old Rover 214 for a new Ford.

Another year of sailing means another year of furling and unfurling, another year of exposure to the sun, another year of flogging and abrading against the rigging and sadly it all takes its toll. The resulting dilemma of whether it is worth spending money on the existing sail or investing in a new one is always tricky.

We all know that sails are expensive and, like a car, they only depreciate but unlike a car, if the clew pulls off when you are sailing away from a lee shore, it can leave you in a very sticky situation. 

Richard Bowers

Richard Bowers. Sail maker at Moatt sails limited

I am Richard Bowers and in this article I will describe six of the most common issues we see when older sails come in for their winter overhaul. Plus some steps that you can take to protect your  investment and eek a bit more life out of them. 


Sail threat number 1: Ultra-violet radiation…remember your sunblock!

Now, I will qualify the following comment but Ultraviolet radiation is the first threat that your sails will ever face. The qualifying caveats are that:

  • you are not constantly sailing at night ( the moon does not cast a lot of UV. Although it does reflect a bit apparently. UV in Moonlight)
  • you don’t have a dog on board ( could easily be the first threat a sail meets if you do!)
  • you have not stored your new sails in the garage or barn (more of that later)
  • your sails aren’t made of dyneema (massively resistant to UV and reassuringly expensive)

I am not qualified to deliver a discourse on the affects of Ultra Violet affects materials but I do know that skin, plastic and sailcloth are all affected to some degree by exposure to the sun. If I tried to bluff, my knowledge would run dry very quickly. Luckily there is a great article which may be of interest if you would like to delve deeper https://www.livescience.com/50326-what-is-ultraviolet-light.html.

Suffice it to say that the problem where sails are concerned is that exposure to the Ultraviolet radiation weakens the base sailcloth. Nylon is particularly badly affected. Polyester (the basis of dacron sailcloth) is slightly more resistant but surprisingly, kevlar is very sensitive while Dyneema is not affected very much, hence caveat number four above. The following link will take you to an interesting graphic comparing the relative loss of strength when various materials are exposed to Ultraviolet radiation. Ultraviolet exposure of UHMWPE fiber (Dyneema)

Just like the cloth itself, the thread used to stitch sails together is also vulnerable to UV. Some threads (Tenara™ is one) are better at resisting UV but all threads will lose strength over time. As a test, try scratching at a seam. If the thread breaks under your fingernail, it’s a good indication that the sail has seen a lot of sunshine. We often see seams which have burst due to weakened thread.

The result of UV exposure is most clearly demonstrated on the UV strips of furling genoas.

Protection from UV

As mentioned before, nylon is particularly prone to degradation by UV so avoid leaving your spinnaker lying in the sunshine to dry for longer than necessary. If you cannot find a suitable space in the shade then just make sure that the spinnaker is moved out of the sun as soon as it is dry.

Roller furling genoas are typically protected by the addition of an extra strip of cloth on the foot and leech. This UV Strip can be considered sacrificial. Not only do they offer the sail excellent protection but they can be replaced once fully defunct. Another option if performance is a priority and the extra weight of the UV strip is not desirable, is a zipped cover which is hoisted on a separate halyard. It costs a lot less to replace a UV strip or renew a cover than to replace a sail.

When it comes to racing sails, it can be tempting to leave your lovely hi-tech genoa flaked on deck between races or during whilst waiting for a sea breeze to build. This, however, is often during the hottest part of the day when the sun is at its zenith and UV radiation at it’s most intense. As mentioned earlier, kevlar is badly affected so if your membrane sail contains kevlar (even the black stuff) it is worth at least covering the sail with a sail bag or stowing it below decks when not in use. This also removes any temptation the foredeck crew may have to lie on it and sunbathe.

Mainsails should be covered whenever they are not in use and a well-designed sail cover will protect your mainsail for many years. Similar to racing genoas, if you are hanging around becalmed between races on a sunny day, it is worth lowering the main and putting on the sail cover.

Sail threat number 2: Flogging

Sailing is a dynamic sport and when a sail is in use it can flog. A classic example is during a tack or gybe and when hoisting. In a racing scenario, a headsail can flog during the build-up to a start. All flogging will put the sailcloth in the body and leech under extra stress. This stress causes the sailcloth itself to weaken and ultimately break down through either damaged fibres and filler of a woven fabric or by causing delamination of laminate cloths and membranes.

This effect can be seen quite clearly in woven fabrics where the surface will initially take on a marbled appearance and eventually the base fibres will become exposed. When sail cloth gets to this stage it will be severely weakened and sails often fail just inside the leech tape.

Modern bonding techniques used in making laminated cloths are much better than in cloths from the past but even so, the sailcloth itself will lose “body” and strength with repeated flogging.

Be prepared….

Like a Scout, it pays to be prepared before hoisting or unfurling a sail. This will minimise the time that a sail is left to its own devices.

For a headsail, having the sheets pre-loaded onto a winch with any slack pulled though will save time and avoid having to load a winch once the wind has caught a sail and flogging has started. This applies to unfurling a cruising headsail as well as to a racing genoa during a tack. The less a sail is allowed to flap, the less stress damage is caused.

Make sure that the sheet leads are correctly positioned to trim the sail efficiently. When furling a roller furling genoa it may be necessary to move the sheet cars forward. Having reefing marks on the foot of the sail and corresponding marks on the genoa tracks. In this manner, the genoa sheet cars can confidently be positioned in the correct spot every time.

Being supported on the luff and foot, mainsails are better supported from the start and therefore less prone to damage from flogging. However, during hoisting or putting a reef in heavy weather, there is a period of time when the mainsail will flog. Being prepared here means ensuring that the halyards and reefing lines run efficiently and are loaded onto a winch in advance. This will minimise the time required to carry out the operation, reducing the amount of time when the sail can flog.

Another approach to reducing flogging damage in mainsails is to install full-length battens. These also make folding easier, particularly when used in conjunction with a set of Lazy jacks.

Sail threat number 3: Chafe

In use, sails are constantly in motion and if they come into contact with parts of your boat or rigging there is the potential to cause damage through chafe. Overlapping head sails probably have the worst of it. During every tack, a large area of the sail will be dragged across standing rigging and if your boat has an inner forestay then this chafe potential is increased.


Standing rigging and fittings attached to your spars can damage your sails so ensure that any sharp edges are removed, covered or wrapped with tape. Additional patching can be fitted to your sails in those areas which are likely to come in contact with abrasive objects. Spreader damage, in particular, can be mitigated against by the addition of spreader patches on genoa leeches and in the body of a mainsail. Also, the area where a guard rail wire meets the pulpit can be a snagging point for headsails. Here again, it is good practice to remove any sharp edges and/or wrap the joint with electrical tape. The addition of extra abrasion-resistant patches to the sail will also protect the sail at that point.

A classic area of potential abrasion

Old maxims ring true!

If chafe does lead to a hole or damaged seams then the old maxim of a “stitch in time saves nine” could not be more apt. The best way to prevent a major break down is to fix even the most innocuous-looking damage before it can spread. One essential part of your onboard equipment has to be a sail repair kit. It can be a simple as a plastic tube containing a needle and some thread but if you are planning on sailing for prolonged periods, it would be useful to have a more comprehensive kit. It could include:

  • Sailmaker’s hand sewing needles at various gauges
  • Waxed thread
  • Sailmaker’s palm
  • Scissors
  • Pliers

Additional pieces of spare cloth, sticky insignia material, stainless steel rings and webbings appropriate to your needs would be great additions. In fact, some discs of the insignia material are a great way to stick a quick patch on a sail in situ.

Sail threat number 4: Salt

Yachts and boats sailed on the sea encounter salt as another invisible threat to a sail’s longevity. The problem begins when salt water penetrates any stitched area of a sail. When the water dries the salt, formerly in suspension, forms into crystals around the thread. Under the action of the sail’s movement, these salt crystals begins to abrade the thread. It is a slow process but over time the thread gradually weakens leading to seam failure.

The solution

The most effective prevention is regular washing with fresh water to return the salt to a solution and rinse it way. For a dinghy sail this is a relatively straight forward part of the packing away routine. Simply rinse the sails after returning to shore whilst you are washing the boat down. Let plenty of water flush over the sail to remove as much salt as possible (and mud if you had a capsize and stuck the mast tip in the putty)

Yacht sails are harder to rinse but less likely to have been covered with salt water to the same extent as a dinghy sail. The obvious exceptions are spinnakers which may hit the water during a racing drop and the foot of genoas which can be coated by spray driven over the bow when sailing into waves.

If your boat is kept on a marina berth, close to a standpipe, then it is possible to rinse the tack area of the genoa with a hosepipe. Even the tack of a roller furling genoa should be accessible and rinsing the tack webbing is recommended as this is a classic area of failure. Your roller furling drum will benefit too! Spinnakers can be rinsed on the foredeck and loosely flaked to dry.

An annual launder and overhaul is the best way to ensure that salt is removed and abrasion damaged is kept to a minimum.


No matter how carefully you look after your sail there will come a point when the combination of salt abrasion and UV damage will cause stitching to become weak. You can test for this yourself by scratching your finger nail over a seam. If the thread is weak it will break easily under very little pressure. At this point it is worth taking the sail in question to a sail maker for assessment. Re-stitching may be an option if the fabric of the sail is still in fair condition.

Sail threat number 5: Mould….If it can grow, it will.

Mould or, for our American cousins, mold and mildew grow in damp, warm conditions. Although it will not have any effect on the performance or the structural integrity of a sail, mould will cause unsightly staining.

Perhaps surprisingly, seawater does not seem to be a deterrent and fresh water is an absolute breeding ground. Whether it’s rain or freshwater from a lake, a sail left damp in a warm environment will soon fall prey to mould and once mould gets a hold it grows quickly and can be very difficult to treat or remove.

Prevention is better than cure…

Ensuring a sail is dry before storing is the single most effective method of preventing mould. We know that UV is threat number one so leaving a sail hanging out to dry for too long is detrimental but providing it is taken out of the sun once it is dry then that is preferable to allowing mould to settle in.

Roller furling sails can be difficult to dry before furling particularly on a rainy day. If it is the case that you have to leave your sail wet then try to make the effort to return on a dry day and unfurl it to allow it to air.

Sails made from laminated sail cloths with polyester taffeta outer layers such as Cruise lam and CDX can grow mould in the slight delaminations caused where a sail is folded. If this is left unchecked it can spread between the layers causing black staining which is impossible to remove. Avoid folding this type of sailcloth on the same fold lines to reduce the chance of local delamination occuring.

Possible cures

If mould has become established, there are a few treatments which can improve the appearance of your sails. As a sail loft, we use the professional cleaning service offered by Tip Top Sails to wash our customer’s sails. Typically, during a winter service, a sail will be washed to remove salt and dirt and then specific treatments can be applied to tackle green mould which is the mould most likely to respond to cleaning. Black mould is more difficult to treat but its growth can be halted and its appearance improved by treatments that Tip Top will use if requested.

It is possible to tackle the job yourself with a soft brush, and plenty of fresh water. You will need a reasonable amount of space and if you are tempted to use a pressure washer then please use it at low pressure and do not place the nozzle close to the sail as this can cause damage to the fabric and burst the seams of a sail.

If you are a brave chemist then, oxalic acid in a very dilute solution can work well. There are proprietary products available such as Star Brite Sail and Canvas cleaner available from good chandlers or Amazon.

At this point, I must warn you not to be tempted to use any biological detergents. These can make your sails photosensitive causing them to go brown when exposed to the sunlight again. An interesting experiment that is probably best left to students of Fox Talbot’s early forays into photography.

Sail threat number 6: Of Mice and men

Of mice:

Your sailing season is over. You have rinsed your sails and dried them thoroughly. During the rinsing process, you have noticed a few small nicks which you have repaired, you have carefully folded your sails and placed them in the safety of your garage or roof space. Imagine how surprised you will be when you take your sails out of storage in the spring, only to find that Mr and Mrs Mouse have eaten their way through your sail!

Sadly it does happen. No matter how careful you are the little rodents will make a beeline for your sails. They love polyester and nylon but they are not eating it, they are using it to make nests.


Mice and rats are difficult to mitigate against. If you can keep your sails in your house, under the bed, that’s probably a safe bet. Garages, barns, and sheds are harder to protect but if that is your only option then using a strong box as protection is wise. The occasional check during the winter is recommended too. You might just catch the meeces before they get too far through your favourite jib!

More patches then Wurzle Gummidge’s trousers !

If disaster strikes the only cure is to take your sail to a sailmaker and ask for a full assessment of the damage and possible repair options. Fortunately for the owner of the spinnaker above, Mr. Mouse had kept all his holes in one panel which meant it was straight forward enough to replace the panel. We have another customer who had stored his a fifty-two foot yacht’s spinnaker in lock-up close to the marina. The spinnaker was in a dowser which held the sail in a neat tube ready for Mr and Mrs Mouse to eat their way through from one side to the other. The result was a spinnaker with more patches then Wurzle Gummidge’s trousers!

..and Men:

This last point relates to damage caused by our own moments of thoughtlessness. Things often happen in a hurry at the end of the season. Flinging sails off the boat on to the dock or bending your rolled up dinghy mainsail to get it into the back of your Ford Fiesta can cause damage in an instant. Add this to storing sails carelessly and we are often the architects of our own downfall.

Your sail is worth more than your outboard…

Manual handling aside (you just need to be careful team) storage is one area where with a bit of thought can mean the difference between hoisting a pristine, well cared for sail in the spring or trying to get the creases out of your pride and joy whilst trying to hide the small wear hole from your wife.

If you can find some space in a dry, rodent free garage with room enough to allow air to circulate, that is nirvana in sail storage terms. Once safely in place, do not allow your children to climb on your sails and do not use a sail as a prop/cushion for the outboard motor (I know you don’t want to scratch the engine’s paintwork but…) or your carbon spinnaker pole (yes, I know how much that cost)

If safe storage is a problem then many sail makers will offer winter storage at reasonable rates. Often this storage will be offered for free in conjunction with winter laundering and overhauls so it is always worth asking the question.

2 Responses to “Years of life left in that…..”

  1. John Hasker December 13, 2019 at 5:23 pm #

    Many thanks Richard. Always a pleasure to read your articles.

    • Richard Bowers December 18, 2019 at 1:36 pm #

      Hi John,

      Thank you for your feed back.

      Have a great Christmas break.

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