A quality mainsail cover is your sail’s first line of defence against the elements. Whether your boat is docked for a few days or left moored for months, a well-maintained cover protects your sail from sun, rain, dust and bird droppings—extending its lifespan considerably. But even the best canvas needs regular care. Here’s how to keep your mainsail cover in prime condition season after season.
1. Rinse Regularly with Fresh Water
Salt crystals are abrasive and, over time, can degrade stitching and fabric coatings. Giving your mainsail cover a light rinse with fresh water after sailing—especially following rough conditions—helps prevent the build-up of salt, dirt and airborne pollution.
2. Wash It Properly—But Gently
When the cover starts looking grimy or develops mildew, it’s time for a proper clean. Use lukewarm water and a gentle soap, like washing-up liquid, and avoid strong detergents or bleach. A soft sponge or brush works best. Rinse thoroughly and allow the cover to dry completely before reinstalling or storing it.
3. Guard Against UV Damage
UV exposure slowly weakens even the toughest marine fabrics. Most sail covers are made with UV-resistant materials, but an extra layer of protection goes a long way. Applying a UV fabric spray once a year can help preserve both strength and colour. If your boat is out of action for a while, consider removing and storing the cover in the shade.
4. Prevent Mildew and Mould
Mildew forms in damp, poorly ventilated spaces—exactly the conditions under a wet cover. Always ensure the sail is flaked neatly and dry before covering. If the cover becomes soaked, open it up as soon as possible to air it out. If mildew appears, treat it early with a mould cleaner suitable for canvas or a diluted vinegar solution, then rinse and dry thoroughly.
5. Inspect Stitching, Zips and Fastenings
Stitching and fasteners wear out faster than fabric, especially in high-stress areas like the mast end or clew. Check zips, twist-lock fasteners and Velcro regularly. Look for fraying seams, loose stitching or rusty fittings and deal with them promptly—either with DIY fixes or a visit to a local sail loft.
6. Store Properly When Not in Use
During the off-season or extended periods ashore, storing your cover properly is essential. Clean and dry it first, then roll it rather than folding to prevent creasing. Store in a breathable bag or canvas sack—never in plastic—to avoid trapped moisture. Keep it in a shaded, dry space with good air circulation.
Final Thoughts
Taking good care of your mainsail cover is straightforward, but easy to overlook. Just a little routine maintenance can prevent costly repairs and extend its service life by several years. Treat your cover well, and it will do the same for your sail.
If you’re ever unsure how to handle a specific repair or cleaning issue, feel free to reach out to the Loong Sails team. We’re always happy to help keep your kit in top shape.
LOONG SAILS-UK LIMITED 