Independent guide: Follow the furler maker's installation instructions and selection charts. This page covers the decisions around the job.

Quick answer

A new headsail furler is sized to the forestay wire diameter and pin size, fitted over a forestay that is usually renewed at the same time, and set up so the halyard leaves the top swivel at the right angle. The drum height, the sail's luff length and the luff tape size must all suit the new unit. Installation is simplest with the mast out, though many furlers can be fitted with the mast stepped.

Decisions before ordering

  • Forestay diameter and pin size decide which models fit.
  • Drum position: on deck, raised on a link plate, or below deck. Raising the drum can improve visibility and clearance over an anchor, but changes forestay length.
  • Continuous foil or sectional foil. Sectional foils ship easily and are assembled on site.
  • Halyard geometry: the swivel height and halyard lead angle prevent wrap.
  • Sail compatibility: luff tape size, luff length and UV strip.
  • Line routing: blocks and fairleads back to the cockpit.

The installation

  1. Measure the forestay and decide on drum height.
  2. Renew the forestay, or confirm it is recent and documented.
  3. Assemble the foil sections over the forestay, following the maker's joint and adhesive instructions.
  4. Fit the drum and connect to the stemhead fitting with the correct toggle.
  5. Fit the swivel and set the halyard lead; add a halyard restrainer if needed.
  6. Route the furling line with good lead angles.
  7. Tension the rig and check forestay sag and mast rake.
  8. Hoist the sail, check furl in both directions and under light load.

By boat

  • Catamarans: the forestay often runs to a beam or bridle; the drum and forestay length need careful measurement.
  • Bluewater yachts: consider serviceability at sea, spare parts availability and a second forestay or cutter rig.
  • Trailer sailers: light furlers that tolerate the mast being lowered and raised often.
  • Racing yachts: headfoils rather than furlers, and sometimes a removable furler for cruising.

Frequently asked questions

Should I replace the forestay when fitting a new furler?

Usually yes. The foil is cut to the forestay length and fitting a new furler over an old forestay means the wire will be hidden for years more. Most riggers recommend renewing the forestay and its terminals at the same time unless the stay is recent and documented.

Will my old headsail fit a new furler?

Often, if the luff tape size matches the new foil groove and the luff length suits the new drum and swivel positions. Many sails need a new luff tape or adjustment by a sailmaker, so check before ordering.

How is a furler sized?

Furlers are sized mainly by forestay wire diameter and pin size, then by boat length and sail area. The maker's selection chart specifies which model suits which forestay; do not fit a unit to a wire size outside its range.