Most of sail care is one habit: dry before stowing. Almost everything that goes wrong with a stored sail traces back to it having been put away damp.
Why drying matters more than cleaning
Salt is hygroscopic. It draws moisture out of the air and holds it, which means a salty sail is never entirely dry even in a dry locker.
That moisture is what grows mould, and mould on sailcloth is difficult to remove, permanently marks the cloth, and its stains are cosmetic while the conditions that produced them are not — persistent damp degrades stitching and, on a laminate, works into any damaged edge and starts delamination.
So: rinse when convenient, dry always.
Rinsing
Fresh water, low pressure, both sides. A hose is right; a pressure washer is not — it drives water into seams and can damage a laminate’s film.
Rinsing is worth doing at the end of a season, after any offshore passage, and any time the sail has been thoroughly soaked in salt water.
It is not worth doing after every sail, and a sail that lives in salt air will never be salt-free.
Cleaning
Most sails need far less cleaning than owners think, and the wrong method does more harm than the dirt does. A sail’s resin finish and its coatings are part of how it holds its shape, and vigorous scrubbing and strong chemicals remove them.
The method depends on what the sail is made of. This is the part that matters most, and it is where the damage happens.
Woven Dacron
The most tolerant. A mild soap solution and fresh water with a soft bristle brush, then rinsed thoroughly. For a genuinely dirty sail, soaking in warm soapy water for a couple of hours before hosing off works.
Ordinary laundry detergent is acceptable. Check the label and avoid anything containing bleach — many detergents include a bleaching or brightening agent, and it is not always obvious from the front of the packet.
Laminate
Do not soak and do not scrub. Hose it off, deal with anything specific by spot-treating gently, and dry it.
The reason is the construction: soaking works water into the layers and into any damaged edge, and scrubbing abrades the film and the taffeta. A laminate is a bonded structure and it does not want water inside it.
Nylon and aramid
Never bleach. Nylon and aramid fibres lose a very large proportion of their strength on exposure to chlorine bleach — the sail comes out looking clean and is structurally a different sail. This applies to spinnakers, gennakers and any sail with aramid in it.
Continuous fibre
Treat as laminate, with additional care for the surface protection, which is what stands between the fibre structure and everything else.
Mildew
Prevention is the whole answer, and it is drying — see below.
If it has happened: on Dacron, a percarbonate-based cleaner used according to its own instructions will lift surface mildew, worked gently with a soft brush and rinsed thoroughly.
Do not use chlorine bleach on any sail. It is sometimes recommended for Dacron, and we do not: the dilution and contact time that lift the stain without attacking the stitching are narrower than they sound, and a mistake is not reversible. If the marks matter enough to be worth a chemical stronger than percarbonate, send the sail to a loft — it is a service job.
On a laminate, nylon or aramid sail, accept the marks. They are cosmetic; the chemicals that would remove them are not.
Stains that have gone into the cloth rather than sitting on it are generally permanent regardless of material.
Never
A pressure washer — it drives water into the seams and can damage a laminate’s film.
A washing machine or tumble dryer — mechanical action and heat, applied to a structure that tolerates neither.
Solvents.
Bleach on anything but Dacron, and never in a detergent.
Drying by hoisting the sail and letting it flog. This is a common shortcut and it does more damage in an afternoon than the dirt would have done in a season.
When to hand it to a loft
If the sail is laminate or continuous fibre and genuinely needs cleaning, if the stain is unfamiliar, or if the sail is valuable enough that guessing is not worth it.
A loft has processes for this and can clean sails that an owner should not attempt. It is worth asking rather than experimenting.
Drying
Completely dry, both sides, before it goes into a bag.
Hoisted in light wind on a dry day is best. Spread on a clean dry surface works. Draped over a boom for an afternoon usually is not enough — the folds stay damp.
What matters is that it is dry, not how it got there.
Folding and rolling
Rolling suits every cloth. A roll is a gentle curve with no hard line anywhere in it. Where a sail can be rolled, roll it.
Folding is what cloth objects to, and laminates object most. A fold is a sharp line, and a film folded repeatedly along the same line eventually cracks along it.
Dacron tolerates folding well. Vary the fold lines from time to time rather than using exactly the same creases all season.
Laminate should be folded as little as possible and never repeatedly on the same lines. Roll it where you can; where you cannot, flake it loosely and put the folds in different places each time.
Continuous fibre the same, with attention to the surface coating — the fibre structure is protected by that surface, and a hard crease works against it.
Nylon packs small and tolerates it, which is why spinnakers live stuffed in bags. It still wants to be dry.
Battens: leave them in if the sail is being flaked on the boom. Take them out if the sail is being folded small for the winter. Battens are numbered, so keep them in order and they go back in the right pockets.
Storage
Dry, dark, ventilated, and not too hot. A locker on the boat is usually acceptable if it is dry. A garage is fine. A hot attic is not — heat ages resin and adhesives.
Off the floor and away from anything that leaks, drips or corrodes.
Not compressed under something heavy for months.
Nothing hard in the bag with the sail.
Mice. They will nest in a stored sail and the damage is expensive. If sails are stored ashore, store them where that cannot happen.
An annual look by a loft
Worth mentioning because it is the cheapest maintenance available and the least done.
A sail seen once a year by someone who works on sails gets its stitching, its edges and its hardware checked properly, and gets small things dealt with while they are small. Restitching a sound sail costs a fraction of replacing it, and a sail that is restitched before its seams fail generally outlives one that is not by a wide margin.
The end of the season, when the sail is coming off anyway, is the time.
Winter, in order
- Get the sail off the boat before the weather turns, not after.
- Rinse with fresh water if it has had a salty season.
- Dry it completely.
- Look it over while it is spread out — this is the best inspection opportunity of the year. See Inspection and Maintenance.
- Deal with anything you find now, when the loft is quiet, rather than in April when it is not.
- Fold or roll appropriately, bag it, label the bag.
- Store it somewhere dry.
The single most useful item on that list is step 4. Small repairs found in November are cheap and done at leisure. The same problems found in April are urgent, expensive and delay your season.
Furling sails left on the boat
A furling headsail that stays on the forestay over winter is exposed to months of weather and takes UV even through its strip, and a strong winter gust can unroll it with nobody there.
Taking it off is better. If it stays, roll it tightly, secure the furling line properly, tie a sail tie around it, and check on it.