Mechanical difference between roller furling and reefing?

duffer1960 · #1 (**permalink**) 06-09-2003

What is the mechanical difference between a roller furling and a roller reefing headsail system? I know roller furling only lets you run with the sail all the way out or fully furled, whereas roller reefing lets you reef the headsail to different percentages. Is the difference only in the foil (stronger), or is there something else? Also, can a roller furling system be converted to a roller reefing system?

Thanks.

Russ

Sailmc · #2 (**permalink**) 06-09-2003

I believe all the systems today both reef and furl. The only time you see a system used only to furl is when someone is furling a mylar sail. These really can''t be used in a reefed posistion without causing damage to the sail.

maxcontax · #3 (**permalink**) 06-09-2003

On my little boats, furling gear had a swivel at the head of the jib, attached to a wire cable along the luff edge to a furling line at the tack: if you partially furl (reef) with this, the load on the sail will torque the luff edge wire and the sail will unfurl. Roller Reefing has a solid bar along the luff edge that will not twist under load, allowing for partial jib sail plans. Mechanically, that was the difference.

geohan · #4 (**permalink**) 06-09-2003

The difference between roller furling and roller reefing/ furling is primarily in the construction of the sail to prevent excessive draft when reefed. My Norlam genoa (dacron/mylar/dacron sandwich) has a piece of 3/4" thick soft foam incorporated in the luff. It is about 12" wide at midheight, tappering to about 2" at each end. Its purpose is to roll up the center of the sail around a larger diameter thus flattening the sail. There are also patch reenforcements on the leach and foot at selected reefing positions.

knothead · #5 (**permalink**) 06-09-2003

You should be able to reef with any furling system that has the extrusions covering the headstay. Without the foam luff you may not get a real good shape but that has never been a real issue with me. I''m usually just trying to reduce sail in a hurry.
Some furling systems incorporate a tack swivel which allows the belly of the sail to start rolling up before the foot and that is also said to give a better shape.
But as was mentioned earlier, if your system is consists of only the furling drum at the bottom, a swivel at the top and the sail has a wire luff, then it was made for furling only.