SailNet Community banner
  • SailNet is a forum community dedicated to Sailing enthusiasts. Come join the discussion about sailing, modifications, classifieds, troubleshooting, repairs, reviews, maintenance, and more!

partiallyfurlled jib good or bad

6K views 20 replies 18 participants last post by  Donna_F 
#1 ·
I've talked to two respected sail makers and they both saiduse all of your jib or none of it. The reason they gave me sounds good.Thier logic is that I'm putting pressure on the jib whereit shouldn't be and that will cause the shape to stretch out and blowout its shape sooner,and suggested a getting a new sail for summer when it's the winds are stronger.Sounds good but than again if I buy a second jib it would be best for them,and not my wallet. I have an islander 30 in the San Francisco bay if that helps.
 
#2 ·
I use my head sail reefed, but I have a foam luff fitted. The sail has good shape to near 50% but any more than that and there is no shape, and my sheet blocks can't be moved any further forward. After 50% furled you'r no longer really looking at performance but just getting out of where you are. My sail is old and on its last leg having had plenty of all weather use.
 
#4 ·
I think my questions would be: how big is your current unfurled genoa and what percentage of the time do you feel you need to sail with it reefed, and how much sail are you taking in? There was a 150 on my boat when I bought it. When it came time to replace it I installed a 130 that I felt suited my vessel ( which tends to take an early reef) and the average conditions in my home waters better. For very light winds I carry a gennaker.

If you feel that you need to substantially reef your genoa "all" summer long on SF bay, then they may be correct in "suggesting" a smaller sail. You may find a smaller sail is still fine for spring and fall as well. I'm not suggesting that you ditch your current sail, If you have a foam or rope luff pad it should help maintain some shape even when furled. Just something to consider when it comes time to replace.
 
#5 ·
Roller furler system vs. reefing furler system

Not all furling systems are made to allow the sail to be partially furled. Systems that do are more substantial than those that don't and the sails are reinforced. The boat I sailed on with a furler that allowed it had a jib with beefier edging and had clearly marked points to which the sail was to be partially unfurled.

Not to say that you can't do it but I believe that you'll compromise the sail. I've been told that it's ok if you don't have a reefing furler system. I prefer to save my sail.

http://www.sailnet.com/forums/learning-sail/77979-jib-furling-question.html
 
#6 ·
If you reef it and it blows out the shape, you'll have to buy a new sail....two sails. If you buy two sails you won't have to reef but you will have to crawl up on deck to change the sails periodically....two sails. I'm not seeing the disadvantage of having roller reefing for your foresail.

goat (confused by simple logic)
 
#7 ·
It also depends on how close to the wind you are sailing. When going downwind, the sail is fully stalled. You are using 100% drag and need no lift, so sail area is everything and shape doesn't matter. You can reef as much as you want when going downwind.

When you are beating, it is the exact opposite. You need all the lift you can get and drag forces cause leeway, so shape is everything. That is when reefing hurts performance most.

What is acceptable is up to you, depending on where you are on the convenience-performance axis.
 
#8 · (Edited)
All sails cut and assembled from FLAT sail fabric material are 'broadseamed' near and towards the luff portion of the sail. Broadseaming is the 'tapering' or narrowing of the 'width' of the panels by cutting away thin curved strips of panel material so that the sail can take on its accurately curved 3 dimensional shape. Broadseaming only occurs in the forward or first 30-40% of the sails cord length.
The resultant 3-dimensional shape (due to the panels being 'broadseamed') is what gives a sail its 'aerodynamic' ability.

If one rolls-up (furls/reefs) the first 30-40% of a sail's cord length, all the broadseamed section of luff to mid-cord panels are no longer 'available' to generate that 3 dimensional shape in the forward part of the sail.

Rx: rolling up beyond 30% of a sails cord length causes a sail to become the equivalent of bowed flat sheet of plywood.
The maximum one can roll up any sail and expect any reasonable shape is about 25-30%, 'maybe'-40%, maximum. Beyond that value the area where the point of MAXIMUM DRAFT is now inside the rolled up material; and, the sail no longer has exposed 'sail draft' other than a flat steady continuous curve - which can not be a 'decent' aerodynamic shape for other than being a 'parachute'!!!!!!!

Another way to look at this is: a 'Cruiser' who has his/her sails 'rolled up' beyond that 30%, and who cant start his/her engine while attempting to claw away ('point'/closehauled) while being 'blown' towards a lee shore will ultimately risk being called - 'beach debris'.

;-)
 
#9 ·
Interesting discussion, never really concerned me, maybe it should. My Neil Pryde Genoa has reefing lines. I reef it often now. Initially I would put on a tough face and leave it out, but now I realize the boat is actually faster when flatter. Life is short man and am not swapping sails. If it wears out I can replace it with the money I saved by not buying the smaller jib. Besides I would rather spend the money on a whisker pole, that is my next purchase.
 
#11 ·
You don't say anything about your sail, one reason can be that the sail is not made for roller reefing..

Sails designed for roller reefing will have reinforcements in the sail to allow for the different load pattern a partly furled sail will see.

There are two different issues a sailmaker need to address
  • A large sail for light air - works better if not to heavy light (weaker) cloth
  • In higher winds you need smaller sail area and heavier (stronger) cloth.
It's difficult to make a sail that cover for all of this.

As other have already have written there is a limit to how much you can reef the sail before it's unusable for upwind work.
Sailmakers have different ways of doing this, but there are limitations to what they can do.
 
#12 · (Edited)
[*]In higher winds you need smaller sail area and heavier (stronger) cloth.
[/LIST]It's difficult to make a sail that cover for all of this.
An all purpose sail made for roller reefing and whose construction is or at some variation of a 'radial' pattern can have lighter weight material at the luff which can easily handle the lighter velocity winds when the sail is fully 'out'; and, when 'reefed' has mostly or only the heavier weight fabric exposed.
The additional benefit of such a multi-weight sail is that the lighter weight material near the luff can be rolled 'tighter' (geometrically) for less turbulence/drag (due to less 'diameter' of the 'roll-up') when the sail is at near the 30% maximum 'roll up'.

:)
 
#13 ·
Hello,

The last headsail i purchased was a %130 UK Halsey Passagemaker. It is designed to be reefed. The furler unit was a Furlex 100S, which is also designed for reefing. The sail had a foam luff so when reefed the sail still had good shape. There were two lines marked on the foot of the sail. When rolled to the first mark the sail was a 110. When rolled to the second it was a 100.

My current headsail is a Hood model, built around 2007. It also has two marks on the foot and has a foam luff. I do reef it and it works well.

Barry
 
#16 · (Edited)
Your sailmaker had a point; furling sails are designed to be flown most efficiently unfurled. 100% unfurled. In heavy weather (near gale force or higher), you should not use a partially furled Genoa. Keep it rolled up. Look to some of the past cruising rallies where boats tried to do this in gale-force winds. Furling gear failed, sails ripped. Rip a furled sail in high winds and seas and you'll have a monster on your hands. Worse yet, you have just placed your crew in harm's way. They will be fighting friction and a pitching foredeck to try to wrestle the sail down. Alternatives include something like the Gale Sail (sleeve wraps around the furled sail) or a removable inner forestay or staysail stay on which you can hank a staysail or storm jib. Be sure to talk with your rigger about the mast support necessary for this arrangement.
 
#17 ·
In the SF Bay, you are going to need to reef. I wouldn't worry about partly furling your jib - the hassle of switching to a smaller sail would dissuade me from doing it. If you're racing, you may want to though.

As has been mentioned, in very high winds, you must not use a furled jib/genoa. The furling line / gear is not designed for those loads, so will fail, leaving you with the full sail at the worst possible moment. If you want a head sail, you will have to put up a storm jib.
 
#19 ·
Thanks guys.This is why I never trust information on a product the salesman is selling.I'm not sure what my sail%is and I haven't spent much time on her yet. Itook my sails to the loft to get aidea of whatkind of lifthey had left.Jib has 5 main has 10. I added 2 reefs to the main and a new uh cover on the jib. I wanted to make sure I don't ruin my jib early. I'be got years on the bay so I know it can go from 5-10 to 20-25 within a few miles or hours. I get good performance in light air and when it starts to get in the upper teens low 20 it gets a little ruff for the family. Know that the main can be reefed things should be smoother and if not I feel better rolling in the jib some.

So in 5 years should I get a 120% radial cut and a cruising spinnaker?
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top