Key takeaways
- Always rinse sails with fresh water and dry them completely to prevent mold and ice-expansion damage.
- Inspect high-load areas and repair minor stitching issues before winter storage to avoid the spring loft rush.
- Roll sails instead of folding them to preserve the resin and sail shape.
- Keep high-tech laminates in temperature-controlled environments to prevent brittle film cracking.
- Store sails off the ground to prevent rodent damage during the long Midwest winter.
The Hidden Enemy of Your Wardrobe
As August draws to a close here in Wisconsin, the evening breeze on Lake Mendota is starting to get that sharp, crisp edge. We still have some great weeks of sailing left, but the reality of a Badger State winter is looming. For many sailors I coach, the focus in October is usually on the hull and the engine. But your sails—the engine of your boat—often get shoved into a damp bag and left in a freezing garage.
If you want your sails to maintain their design shape and structural integrity, how you treat them during the off-season is just as important as how you trim them on a reach. A frozen, damp sail is a recipe for delamination and mildew, both of which will slow you down on the race course next spring.
The Freshwater Rinse and Dry
Even though we aren't dealing with salt on the Great Lakes, our sails pick up plenty of grime. On Lake Michigan, city soot and lake spray leave a fine residue. On inland lakes like Lake Winnebago, we deal with algae and organic matter.
Before you even think about folding them, you must rinse them. I like to pick a dry, low-wind day to hoist the sails at the dock and spray them down with fresh water. If you have stubborn stains, use a very mild soap and a soft sponge. Never use a power washer; the pressure can easily blow out the resin that gives Dacron its stability.
Crucially, you must ensure the sails are 100% dry. I once saw a student store a slightly damp mainsail in a plastic bin over winter in a Milwaukee storage unit. By May, the sail was covered in black mold spots that had eaten into the fibers. Because the water expands when it freezes, moisture trapped between the layers of a laminate sail can actually cause the layers to pull apart.
Inspection: Catching the Small Tears
Winter is the best time for a thorough inspection. Lay the sail out on a clean floor. I tell my students to look specifically at the high-load areas: the headboard, the clew, and the tack. Check the stitching on the batten pockets and the sacrificial UV cover on your jib.
If you find a small nick, fix it now with some PSA (pressure-sensitive adhesive) sail tape. If the stitching is fraying, it’s much cheaper to send it to a loft in November than to wait until the April rush when every sailor in the Midwest is trying to get their boat ready for the first regatta. According to the Racing Rules of Sailing (RRS), you are responsible for your equipment; a sail that fails mid-race because of a neglected tear isn't just a bummer, it's a safety hazard if it happens in heavy air.
Storage Strategies for the Deep Freeze
In Wisconsin, the temperature swings are dramatic. We go from 40 degrees down to -20 in a matter of days. These fluctuations cause materials to expand and contract.
- Avoid Tight Folds: If you have the space, roll your sails rather than folding them. Rolling prevents permanent creases in the cloth resin. For my racing jibs, I use long PVC pipes to roll them and then hang them from the rafters of my garage to keep them off the floor.
- Pest Control: Mice love nesting in sailcloth. It’s warm, soft, and quiet. Do not store your sail bags directly on the floor of a shed or barn. Use a shelf or a hanging system. I’ve seen a brand-new carbon fiber main ruined in one winter because a rodent decided the luff tape made a great snack.
- Climate Control: If you have high-tech laminate sails (Mylar or Kevlar), keep them in a basement or a temperature-controlled environment. The extreme cold of a Wisconsin winter can make the film brittle, leading to cracking when you first unfurl them in the spring.
Real-World Example: The Lake Michigan Lesson
Last year, a local J/105 sailor left his genoa in the turtle bag on the boat, covered only by the winter tarp. The tarp leaked near the bow, water pooled in the bottom of the bag, and then it froze solid. The ice crystals acted like tiny knives, cutting into the fibers of the sail. When we pulled it out in May, the bottom three feet of the sail were structurally compromised. That’s a multi-thousand-dollar mistake that could have been avoided with twenty minutes of work in October.
Take the time to treat your sails with respect this off-season. Your boat speed (and your wallet) will thank you when the ice finally breaks next year.
Written by Dmitry Shteyn — Wisconsin sailor and educator. Find more sailing notes on the daily blog or read the longer guides.