Harken: Furling Questions and Answers

Furling—Q & A

How do I select the right furling system for my boat?

Harken furling systems are sized according to headstay and clevis pin diameters. Harken furling systems come with a variety pin diameters, but only one is correct for your boat. It's also handy to know the headstay length to determine if additional foils are needed. Use the I and J measurements to determine the length of the headstay. Contact Harken if you have questions.

Are all Harken furlers capable of reefing a headsail?
Yes, as long as the furling system has aluminum extrusions covering the headstay.

Can I use my old sails with my new jib reefing and furling system?
Yes. Ask your sailmaker to modify the sails you use regularly, including at least one genoa and one heavy- air sail. If you sail in an area that requires specialty sails like drifters, convert these as well. Sails should be in good condition.

How are sails modified for jib reefing and furling systems?
Your sailmaker will remove the hanks and add a luff tape so the sails slide into the foils. Larger sails may need to be shortened to make room for the halyard swivel. Adding a suncover to your most frequently used sails will protect them from ultraviolet damage when furled.

What should I look for when I purchase a new sail?
Look for a sail designed for a range of sailing conditions. It should have shaping devices in the luff for improved sail shape while reefed, but still be able to handle reefed sailing loads, and sun protection.

What's the best way to protect my sail from the sun?
Any sail left rolled on the headstay needs protection. Prolonged exposure, to ultraviolet rays will destroy sailcloth.

Some sailmakers use UV-proof sailcloth. This cloth can be used on the genoa foot and leech panels without adding a lot of extra weight. Most sailmakers prefer Acrilan®-type covers (the same material used for mainsail covers) sewn on the sail leech and foot.

Some use a long sock-like wrap to cover a furled sail. The advantage is you can cover any sail without adding weight to your genoa. The disadvantage is you’ll have to raise the cover on a spare halyard and fasten twist snaps or zip the sock closed. These covers can flog in a breeze.

Can I change sails with my Harken jib reefing and furling system?
Changing Sails Yes, easily. Changing furling sails is similar to changing a hank-on jib. Simply attach the head and tack of the sail to their shackles, pass the luff tape through the prefeeder and feeder, and raise the sail. The prefeeder and feeder remove wrinkles and minor twists in the sail so you can raise sail while at the mast or standing in the cockpit. If you plan to make a lot of sail changes, you should order the optional head and tack snap shackles.

SAILS, SHAPE, SIZE & DESIGN

Will my sails still have a good shape when reefed?
Harken furling systems have independent halyard and tack swivels that furl the sail's center before the tack and head. The resulting flatter sail is good for reefed sailing. The shape is not as good as a sail designed specifically for reefing, but is much better than a unit without independent tack and head swivels.

What size genoa should I use as my primary reefing sail?
This depends on your boat and your normal sailing conditions. Most boats find a 150 percent genoa ideal. However, if you sail in a windy area, you may want to use a 125 percent genoa. In a light-air area, a larger genoa may be needed. Discuss sail size with your sailmaker.

What is the proper luff tape for my Harken furler?
Units 00AL, 0, 1, 1.5, 2, 2.5, 3, 3.25, and 3.5 use #6 luff tape. #6 luff tape is 0.1875" in diameter (about 5 mm). Unit 4 and 4.5 furlers use # 6 or #7 luff tape, #7 luff tape is .218875" (about 6 mm) in diameter.

Sail Clews Most furling sails are designed with a high clew to give the lower part of the sail a better wrap around the foils, as well as to improve visibility under the sail. We’ve found a sail with a moderately low clew has the greatest efficiency and that it will maintain good visibility because the tack of the sail is raised off the deck.

I've heard you can't really reef a sail. Is that true?
You can reef sails using a Harken system. If you reef a standard sail, your sail shape will be fair. You will also have to choose which sail to
set, and understand that it won't work well in all conditions. A specialized reefing sail will maintain good sail shape through a wind range of five to 40 knots. Additional sail shape adjustments can be made by increasing or decreasing halyard tension and by changing genoa lead block position.

Reefing works well, so why do I need more than one jib?
Experienced seamen never sail without a heavy air jib because even the best reefing sail can be damaged. In a blow, you should change to a heavy-air reefable sail before leaving the harbor. A storm jib is vital for offshore passages because of the possibility of hurricane weather. If you live in a light air area, sailing will be lots more fun if you use a light air sail.

QUESTIONS FOR YOUR SAILMAKER

What does it cost to add luff tape to my sail?
Costs vary, but most sailmakers base prices on luff and leech lengths.

What brand of sails should I buy?
Select a sailmaker who offers answers that show an understanding of reefing and furling systems.

How strong should my reefing jib be?
The sail should be powerful enough to move the boat efficiently in light air and chop, but flat enough to sail reefed in severe conditions. Modern shaping devices allow sailmakers to build sails that work in winds ranging from five to 40 knots. Most sailmakers use foam or rope luff pads. Some use the Aeroluff® system. Ask your sailmaker which shaping device is best for your boat.

Can I use my cruising spinnaker with a Harken furling system?
Yes. Most cruising spinnakers attach to the headstay with a snap shackle. Ask your sailmaker to replace the shackle with one that works with a furled sail. He will probably use a padded strap or string of beads to hold the sail near the headstay.

I am a competitive racer, but I also like the convenience of furling. Can I use my racing sails on a Harken system?
Yes. Most racers don't use a #1 genoa on the furler because the luff is usually too long and construction too light. A #2 or smaller genoa should be strong enough to handle reefing and short enough to use with your furling system. All Harken furlers feature an easily removable drum that allows you to use the dual groove extrusions as a twin-foil headstay.

Can I still use my hank-on jib with a Harken Small Boat furler?
You can use the jib if you replace the hanks with luff tape. You do not need a new jib cut. Most sailmakers can do this for you.

CODE ZERO FURLING

Can I use a Code Zero furling for a Screecher sail on my trimaran?
The Code Zero furler was designed to handle the massive sail area of upwind spinnakers on ocean racing boats, but it can also be used with Screecher sails. Because the single line driver of the Code Zero furler is fairly large, there is more torque power when rolling up the sail. If a Screecher is used in heavier air, rolling up the sail is considerably easier.

If the sail is somewhat oversized, the continuous line can handle any amount of sail without the drum filling up with line. The disadvantage is that because the line is continuous, there are two lines to deal with instead of one.

For cruising sailboats, we have a dedicated Screecher furler that works off the same concept as a standard headsail furler. A Screecher furler only has one line and the cost is a fraction of a Code Zero.

SMALL BOAT FURLING SYSTEMS

Can Small Boat furlers be used for reefing the headsail?
No. Small Boat furlers do not have a foil system and cannot be reefed. You should only sail with the headsail completely furled or unfurled.

How are Small Boat furlers attached to the sail and boat?
Headsails used on Harken Small Boat furlers require the installation of a luff wire onto the sail. The luff wire comes out from the luff at the head of the sail and attaches to halyard swivel. The top of the swivel attaches to the halyard. The bottom end of the luff wire attaches to the top pin of the furler’s spool assembly.

Small Boat furling systems can be installed either as an integral part of the headstay or behind the stay as an independent part.

How do I fly multiple headsails if I have a 436 furler?
You should install the furler behind your stay. Some boats have a chain plate at the bow with multiple holes. The headstay goes to the forward hole and the lower unit is installed in one of the holes behind it. The 426 halyard swivel has a stainless steel crane that keeps the halyard swivel close to the stay.

Can I store a sail on my Small Boat furler?
Yes, you can store your sail furled on the furler so it’s ready for the next time you use your boat. If you leave the boat with the rig in place and the sail furled for long periods, make sure the sail has adequate protection against UV damage. Your sailmaker can sew a sunscreen on in a narrow strip along the foot and the leech of the sail. When the sail is furled, the screen will be the only portion of the sail exposed to the sun. Remember to furl the sail so that the sunscreen is on the outside.