Sail Maintenance

Things that damage sails:

Chafe (causes damage very rapidly).
Ultraviolet radiation.
Salt and dirt in the weave.
Over-stressing (usually just the last straw on top of other damage).
Exposure to solvents/acid (rare).

Inspecting sails for damage:

Batten pockets.
Stitching on all edges of sail (especially leech of headsail).
Stitching of all seams.
Grommets and rings, including reef-points.
Slides on mainsail.
Leech-line (and its cleat).
Tears, punctures and chafe damage of material.
Headboard of mainsail.
UV cover on roller-furling head-sail.
Chafe guards.

North Sails "Sail Care Tips"
SailNet - Dan Dickison's "Racers' Sail Care Tips"

Washing sails:

Use fresh water, mild liquid dishwashing detergent, and sponge (no brush).
Rinse and dry.
Never stow sail wet. If you have to, don't bag it and don't fold or roll it tightly.

From Rich Hampel on alt.sailing newsgroup:

I do the cleaning while the sails are on the boat. I clean the deck, and spray on the detergent as I have someone slowly raise the sail. I use a long handled brush and scrub the offending spots as the sail goes up, then lower and place a plastic tarp over the soggy mess. The plastic tarp makes sure the detergent doesn't dry out. After about 30 minutes (you have to let enough time to let the detergent work) I re-scrub, lower, then raise the sail several times as I rinse with a hose. Make sure that you get ALL the detergent out of the sail. Several rinsings will be necessary. Then go sailing to dry the sail.

Removing stains from sails

Mostly from "Sailing Tips" by William M. Burr Jr., and from sail-repair class at Hogin Sails:

Rust: Keep the area wet. Use lemon juice (let soak for an hour). If it fails, use detergent. If it fails, use acetone or alcohol or M.E.K. If it fails, use a weak solution of oxalic acid.
Blood: Keep the area wet. Use soap and cold water.
Or: Rub gently with fresh or salt water for a long time. If it fails, use detergent. If it fails, use bleach 1-10 in water and rinse thoroughly.
Mud or grass: Use detergent.
Mildew: Use lemon juice. If it fails, use detergent and bleach (carefully: bleach damages sails) and rinse very well.
Oil/grease/tar: Hard to remove.
Use hand-cleaning jelly used by car mechanics: rub in, leave for an hour, rub more in, scrub with soap and warm water.
Or: Use rubbing alcohol, trichloroethylene, or mineral spirits, then soap and water. Rinse thoroughly.
Paint/varnish: Use acetone or alcohol or M.E.K.
Fresh glue: Use mineral spirits (soak).

SailNet - Kathy Barron's "Sail Care and Cleaning"

In a good rain, wash the salt out of all of the sails (the spinnaker especially will be lighter and more efficient).
In spots vulnerable to chafe, brush "sailmaker's liquid plastic" onto the stitching.

Sail reconditioning: SailCare (people who have done this have mixed feelings: may be good money into a worn-out sail, may damage stitching. Best on a relatively new but dirty sail.)
SailNet - Brian Hancock's "Considering a New Mainsail"
Sailmaker's Supply

Sail-repair:

SailNet - Don Casey's "Sail Repair 101"
SailNet - Don Casey's "Sail Repair At Night, Sailor's Delight, Part Two"

Some items learned at sail-repair class at Hogin Sails:

Inspect sails often and fix damage right away. "A stitch in time saves nine" really is true.
Sail-repair tape by itself can be used to patch very long tears on a spinnaker, but not on heavier sails.
Use Dacron/polyester thread: it is UV-resistant and you can melt the end (making a small blob) instead of knotting it.
On a sail, white thread lasts longer than dark thread.
Patch material should match sail material in terms of weight, stiffness, stretchiness. Orient the weaves of the sail and the patch in the same direction.
When patching a tear in the middle of the sail, people usually make too small a patch. The material around the tear probably has been stretched and weakened.
Seal all cut edges of sail material with hot knife.
Can use round-point needles for canvas, but not for sails.

See my Boat Sewing Machine page

Cleaning the mast track: use a soapy cloth tied to a spare sail slide, with a halyard and a downhaul. Lubricant: silicone makes a mess; liquid soap is cleaner but doesn't last as long.