What Is Furling?
A drum-and-profile arrangement that rolls the sail away with a pull on a line — the bit that makes short-handed sailing possible, and the one most often left until the last minute on maintenance.
Furling is a system that stows the sail by rolling it around its own axis: on a headsail, a profile wraps around the forestay with a drum at the bottom; on a mainsail, the furling gear is built into the mast or boom. Furling is what opened the door to sailing short-handed, often just as a couple.
The system puts a lot of strain on a single moving assembly: a drum bearing, a line that builds up unevenly, or, on in-mast furling, the wrong boom angle can lock the sail at the worst possible moment.
Maintenance and rules
Fresh water: wash the drum down with fresh water once a season to clear salt from the bearings.
No forcing: if furling starts to stiffen up, never force it with the winch; resistance is telling you something is wrong, and the winch will turn that message into an expensive breakage.
Annual check: check the profile joining screws and make sure the furling line is winding on evenly.
Most jams on in-mast furling are not technical failures but user error: when furling, the boom angle and sheet tension must be set to the maker’s instructions. If the furling line winds onto the drum unevenly and climbs over itself, it will bind; the line diameter and pre-tension must be set up correctly.