Independent guide: Furler designs differ between makers. Follow the manufacturer's service instructions and use the parts specified for your model.
Quick answer
A headsail furler is a bearing drum at the bottom, a foil around the forestay and a swivel at the top. It needs servicing when furling becomes stiff, noisy or uneven, when the halyard wraps, or when the forestay inside it is due for replacement. A service cleans or renews the bearings, checks foil joints and the swivel, and corrects halyard lead and tension. Because the forestay is hidden inside, a furler service is also the main chance to inspect the forestay.
Signs your furler needs attention
- furling is stiff even with the sheet eased
- grinding, clicking or squealing from the drum or swivel
- the sail furls unevenly, with a baggy top or tight bottom
- the halyard wraps around the foil
- visible play or wobble in the drum
- corrosion or white powder around the drum
- the furling line jumps off the drum or rides over itself
What a furler service involves
- Drop the sail and inspect the luff tape and UV strip.
- Check the halyard lead. The halyard should leave the swivel at a small angle to the forestay; a restrainer at the mast often fixes wrap.
- Service the drum. Flush, clean or replace bearings as the maker specifies; check the line guide and drum fastenings.
- Service the top swivel. Spin under light load; renew bearings if rough.
- Inspect the foil. Check joints, connectors and straightness, and look for wear at the feeder.
- Inspect the forestay terminals as far as the design allows — often only possible with the furler partly dismantled or the mast out.
- Reset furling line leads so the line enters the drum at the correct angle.
Repair or replace?
| Situation | Usually |
|---|---|
| Bearings rough, everything else sound | Service or bearing replacement |
| Foil damaged at one section | Replace that section, if parts are available |
| Unit is old and parts are discontinued | Replacement |
| Forestay due for replacement | Service with the new forestay, or replace the whole unit |
| Upsizing the forestay | Check foil compatibility; often replacement |
See furler installation for what a new unit involves.
Furlers by boat type
- Catamarans: large headsails on long forestays; furling lines run a long way aft and need well-aligned leads.
- Cruising yachts and liveaboards: the headsail may stay furled on the forestay for months, so UV strips and swivel condition matter.
- Charter yachts: heavy use by many crews; drums take abuse from unfurling under load.
- In-mast and in-boom mainsail systems have their own service needs — see in-mast furling and furling systems.
Owner care between services
- rinse the drum and swivel with fresh water after sailing
- keep a couple of turns of furling line on the drum when the sail is out
- never winch the furling line hard when it resists; find out why
- ease the sheet before furling and keep light tension on it as the sail rolls
Frequently asked questions
Why is my headsail furler hard to turn?
The usual causes are dirty or worn bearings in the drum or top swivel, a halyard wrapped around the foil, too little halyard tension, a bent or damaged foil, or a furling line chafing on a poor lead. Check the halyard lead angle and tension first, then have the bearings serviced.
What is halyard wrap and why is it dangerous?
Halyard wrap is when the headsail halyard winds around the forestay or foil instead of the top swivel turning. It jams the furler and can damage the forestay wire or its terminals, and a wrapped forestay has failed in some cases. Correct halyard lead angle and a halyard restrainer at the mast usually prevent it.
How often should a furler be serviced?
Rinse the drum and swivel with fresh water regularly and check function every season. Many owners have the furler professionally serviced when the mast is out or the forestay is replaced, and sooner if it becomes stiff, noisy or develops play.