Proper sail maintenance is easy and takes little time, but it can make a big difference in the life and performance of your sails. Whether you have new racing built from Kevlar® or Dacron cruising sails that are several years old, a little care can maximize the value of your investment.

Avoid flogging

The best way to maintain the strength and shape of your sails is to minimize the amount of time they are flapping in the breeze. Flogging and leech flutter degrade cloth properties quite quickly, so every effort should be made to avoid these actions. This is especially true with Kevlar® sails, which could lose all their strength in a few hours.

There are a few specific ways to increase the life of your sails. Don't motor into the wind at full throttle when hoisting your main. If you are powering with the main up, keep it trimmed so it doesn't flap. In heavy wind, reduce sail enough so you don't have to flog the main. Always keep your main and genoa leech lines tight enough to stop the leeches from fluttering.

Don't exceed the recommended wind range

One of the quickest ways to destroy a sail is to use it in more wind than it was built for. The best way to avoid this is to stay strictly within the maximum wind speed recommended by your North sailmaker for each sail. Usually this limit is stamped on the clew of each racing headsail. If it isn't, find out what the maximum is from your sailmaker and write it on the clew so the crew knows each sail's range.

Reduce chafe

Chafe is another enemy of sails. The more a sail rubs against any part of the boat or spars, the sooner it is likely to show failure. There are a couple of good ways to extend the life of sails: First, avoid chafe whenever possible, i.e. don't let the running backstays rub against the leeward side of the mainsail; don't drag sails over non-skid decks, around shrouds, or along the dock.

Second, when you can't avoid chafe, at least minimize it. Use tape or leather to cover spreader tips, stanchion tops—any part of your rig that constantly rubs on sails. This is especially important when using light sails such as spinnakers or light genoas. Check your boat for untaped cotter pins, sharp corners on fittings, unprotected burrs, screw heads, halyard hooks, etc. and tape them. Remember to check the front of the mast carefully, since your genoas drag across it every time you tack.

Protect from the sun

Direct sunlight is one of the worst enemies of sails since it will eventually cause breakdown of the cloth. Therefore, your goal should be to keep your sails out of the sun whenever you are not using them. A roller furling headsail, for example, should definitely have UV material on its leech and foot for protection when it's rolled up. If you flake your main on the boom, always put a cover on it.

Store sails dry and folded

When not in use, your sails should be stored dry, free of salt, and folded in their sailbags. Don't fold them on the same creases every time, as you will have eight or ten permanent creases instead of many light ones that gradually shake out by the time you reach the starting line. Most one-design sails will last longer if they are rolled in their sausage bags. Store a spinnaker dry and loosely stuffed in its turtle or folded in its envelope bag. Don't store spinnakers wet for any length of time, as darker colors will bleed into lighter ones, and dampness promotes the growth of mildew.


North's state-of-the-art fabrics give sails a better shape and longer racing life than ever before. We test every lot of material used in North sails to get the best value for your money. However, today's fabrics also require a bit more care to keep them performing to their potential as long as possible.


Sails made of Mylar film laminated to a polyester substrate provide good strength for their weight, but they are also relatively fragile, so it's wise to:
  • Never exceed your sail's recommended wind range
  • Never use a genoa that doesn't have spreader patches
  • Don't flog the sail unnecessarily
  • Don't overstretch the luff of a Mylar sail. Mylar sails need only a bit of luff tension to position the draft correctly. Therefore, tension the halyard and Cunningham only enough to remove horizontal wrinkles from the luff. Mark the genoa halyard so you don't over-tension it when coming into the leeward mark.
  • There are other precautions you should take with Mylar sails. Don't let any solvents (such as diesel fuel or cleaning agents) get on them, because these will dissolve the glue and cause separation. Mylar film is sensitive to heat, so be sure not to let your sail touch any part of the engine or even rest against an interior.


Kevlar is exceptionally strong for its weight, which means it won't stretch nearly as much as Dacron or Mylar. That's why you'll find Kevlar in many racing sail leeches, where loads are the greatest. However, Kevlar can also break down quickly if not treated properly. The key with a Kevlar sail is to avoid flogging and leech flutter.


This material is the most widely used for both racing and cruising sails. It offers very good durability, but all of the precautions mentioned here should still be taken to maximise the life of your sails.


Nearly all spinnakers and Gennakers are made out of nylon. This material is popular because it is lightweight and strong. However, since nylon is light it can tear quite easily, so be careful when handling it. If you get a small tear, you can tape over it temporarily, but get the sail repaired by your sailmaker as soon as possible.


No matter what your sails are made of, there are a few guidelines you should follow to prolong the life of each particular sail.

Head Sail Care

The most common sail damage is caused by using headsails, particularly light No. 1s, in too much wind. If a puff comes through unexpectedly, ease the sheet to keep the sail from loading up too much. If the increase in wind is sustained, change to a heavier sail. Another common cause of damage is tearing or splitting caused by backing the sail against the spreader. The first thing you should do is have spreader patches installed in the proper locations. Also make sure the spreader ends (and the forward stanchion tops) are well-protected with leather and/or tape. Even with these precautions, however, the sail may fail if it's backed hard on the spreaders.

Here are some good ways to prevent failure:
  • Make sure your jib tailer casts off the jib sheet early enough on the tacks and doesn't overtrim coming out of the tack
  • Don't use wheels, rollers or pads that extend the spreader tip beyond the shroud (less protrusion means less damage)
  • Inspect seam stitching in spreader areas periodically
  • Keep the leechline tucked away in its pocket— not flying free
  • If you have a grooved headstay, be sure to use the pre-feeder so you won't rip the luff tape
  • Don't trim on the sheet until the halyard is all the way to the top

Mainsail Care

Mainsails take a lot of abuse because they are used in all conditions. Therefore, it's especially important to treat them carefully in order to maximise their useful life. As mentioned, the most important consideration especially with a Kevlar main, is to avoid flogging. Always trim the sheet hard enough to settle the sail and prevent hard flogging of the leech.

Some other ideas:
  • Keep the leechline tight enough to stop flutter
  • Don't pull too hard on the Cunningham of a laminated sail
  • Make sure the battens are inserted properly
  • Use colored sailties when reefing so you won't miss them when unreefing
  • Make sure the reefing line is led so you don't pull too hard on the foot
  • Spreader patches will help the main last longer when it is eased against the rig for running

Spinnaker Care

Nylon is relatively stretchy, so it's able to absorb large loads without breaking. However, spinnaker material is quite light and can easily fail from use in too much wind. Explosive refilling after a collapse is definitely a problem. Another common cause of failure in spinnakers is tearing on sharp objects. This often happens on sets or takedowns, so be sure that these areas are catch-free. You should also be sure that your genoa halyards are free of "meathooks" and that the pulpit doesn't have any snags.

One Design Sail Care

Like all other sails, avoid flogging. Sometimes, such as starting, this is unavoidable, but in between races you should definitely drop your sails instead of letting them flap. It's a good idea to break new sails in for a few hours before using them in racing conditions. Yarn-tempered sails should be rolled when not in use. If your sail has a window, avoid storing it in high-temperature areas like car boots/trunks. A good way to keep sails salt-free is to put them up on a CALM day, hose them off and let them dry in place.

At the end of the season, if you bring your sails to your North Sails Service Centre, we can check them over and do any necessary repairs. Though all sails age with time, properly cared for sails will give you much more value for your money than those left flogging in the breeze.


  • Ensure that the sails are aired regularly, especially after rain. This may mean unrolling the headsail at the mooring for an hour, on a calm, dry day.
  • Exposure to sunlight is helpful but too much causes other problems.
  • Do not put away damp or salty (the salt attracts and retains moisture), and store in a dry location.
  • If the boat is to be left for more than a week or two, take the sail off the rig and store it dry, or arrange for somebody to air it regularly and especially after rain.
If mildew occurs...
Treat mildew at the earliest possible moment. If you do not, it can spread quickly. There is an excellent chance of getting mildew stains off when they are new, relatively small, and close to the surface. There is little chance once they have spread and set into the fibres.

Isolate mildew-infected sails, anchor lines, covers, and so forth, from clean sails. The quickest and surest way to spread mildew is to rub an existing growth against a receptive surface.

The single most popular mildew killer and remover is simple household bleach. This is also known as sodium hypochlorite, sold in the U.S. in 5.25% solution with water. This is potentially nasty stuff and manufacturers recommend diluting it quite a bit further before using. Tilex® and other "mildew removers" are mainly sodium hypochlorite in solutions of about 3%, which is still a pretty healthy dosage.

This is one of the few known, proven solvents for these fibres. We have seen people poke their fingers easily through spinnakers rinsed in chlorine-treated (same as bleach) swimming pools. Of course, this means you should not clean Kevlar and nylon with Tilex® or other commercial mildew cleaners that contain sodium hypochlorite.

CAUTION: DO NOT EVER MIX BLEACH AND AMMONIA. The result is phosgene gas which killed and disabled thousands in the First World War. This little home science experiment continues to kill and cripple people to this day.

For particularly stubborn, deep set stains, surface cleaning will not work. It is necessary to immerse the stain in a fungicide for 12 hours or more, to allow it to get in to where the stain is. It is not necessary to use a particularly high concentration, only to get the fungicide where the stain is. No amount of vigorous surface scrubbing will do what a good soak will do.

After washing with bleach, always rinse thoroughly with plenty of fresh water. Bleach that is not removed can cause long-term structural damage that is more harmful than the cosmetic damage caused by the mildew.

If the mildew stain does not come out after one good wash with the proper equipment and chemicals, give up. Experience shows that further washings/scourings/ treatments remove very little additional stain and cause a lot of other damage.

Scotchguard® and related water repellents do not have any properties that either kill or prevent the recurrence of mildew. They may be marginally effective at repelling some of the moisture and nutrients on which mildew feeds, and might make cleaning easier by holding the stains away from the fibres. However, there is not much evidence either way on this.

Dettol®, a commonly available household disinfectant, is the most powerful and effective fungicide and inhibitor you can use to prevent recurrence and spread of mildew. Various health and environmental agencies prohibit the use of stronger fungicides since the same thing that kills fungus has similar effects on higher life forms, as most of us would like to picture ourselves.

Anything you use on a sail to kill or remove mildew and stains, will wash or wear away in a relatively short time. This is directly analogous to anti-fouling bottom paints. North NorLam™ fabrics are treated with the most powerful commercial fungicide we can use without jeopardizing the health of employees and customers. It is 100% effective in preventing mildew in laboratory conditions, and demonstrably less effective in the real world.