Mainsail Leech Problem

Jan 22, 2008
763
Hunter 340 Baytown TX
Part of my mainsail leech twists off to leeward. It's very noticeable since it's right at a draft stripe and reef reinforcement. Sail is 3 or 4 years old. Leech line is tight and battens seem okay. What do I look at next? Are there other trim adjustments or is a repair needed?
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Jun 9, 2008
1,771
- -- -Bayfield
Hard to totally tell, but your mainsail draft is further aft than your headsail. Tightening the mainsail halyard (or cunningham, if you have one) will bring the draft forward, which might help. Obviously you are sailing in a stiff breeze given the way you are heeled over.
 
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Apr 21, 2014
184
Hunter 356 Middle River, MD
Seems like you might have extra or stretched fabric along the leech which may require re-cut by the sail maker.

Picture looks like a lot more than the 15 degree heel recommended by the designer...although I really like your race videos.

Jeff
 
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May 17, 2004
5,028
Beneteau Oceanis 37 Havre de Grace
Have you ever used that third reef point, or do you know if a previous owner may have? It looks to me like the cloth is stretched right there allowing the extra to fall off.
 
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Jan 22, 2008
763
Hunter 340 Baytown TX
Have you ever used that third reef point, or do you know if a previous owner may have? It looks to me like the cloth is stretched right there allowing the extra to fall off.
Good point, it’s the second reef and I have never used that reef and I bought the sail new in 2016. To me, it seems like something is stretched or distorted, but it’s right at the reef reinforcement that should not stretch or distort.
Top photo is from last Saturday, with the first reef in. Bottom photo is a couple weeks ago in a race when we got caught with too much sail up when the wind increased.
 
Jan 11, 2014
11,321
Sabre 362 113 Fair Haven, NY
The leech line looks a little tight, that will cause the leech to curl to weather.

In the second photo the topping lift looks like it is still attached to the boom and is tight. This is lifting the end of boom up, reducing tension on the leech. With less tension, it will slack off to leeward. Take the topping lift off or loosen it enough so that it flops around.
 
Jan 22, 2008
763
Hunter 340 Baytown TX
The leech line looks a little tight, that will cause the leech to curl to weather.

In the second photo the topping lift looks like it is still attached to the boom and is tight. This is lifting the end of boom up, reducing tension on the leech. With less tension, it will slack off to leeward. Take the topping lift off or loosen it enough so that it flops around.
Thanks, both good points. It's hard to tell, but the topping lift is loose and streaming aft. Sail foot was cut wrong and topping lift is adjusted every time we raise or lower the main. Foot was cut flat instead of having a raised clew that the rig was designed for so it's too close to the arch. I've got the TL on a 4:1 with a clam cleat at the base of the mast. Since I noticed the curl to leeward a couple weeks ago, I have tried every leech line setting from completely loose to tight as it can go. There is a little less curl when it's tight.
I should be on the bay this Saturday and I'm going to mess with batten tension. I'm constantly adjusting the big full batten. Too loose and it's a wrinkled mess, too tight and it forces too much draft. But, I haven't messed much with the two lower partial battens.
I do keep a tight mainsheet and thus tight leech when the wind is up, to act as a proxy backstay to try to get a little sag out of the forestay and try to point better. Probably not doing a lot of good. It may be better to twist off and just sail flatter. Definitely better to reef, but it takes too much time to shake out the reef for the reaching leg where the big main can actually keep up and maybe pass a few other boats.
 
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Joe

.
Jun 1, 2004
7,999
Catalina 27 Mission Bay, San Diego
May not be what you want to hear.... but I don't think there's anything wrong with your sail that a little de powering won't help. Ease off the mainsheet, drop the traveler a bit, check your draft position with the Cunningham, get the boat upright and you'll sail faster.... which is the point, right?
 
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Oct 19, 2017
7,732
O'Day 19 Littleton, NH
I like what Joe has to say. I would also like to see the genny sheet moved aft. I think the draft in the slot is affecting your mainsail shape.
How is the leeward stay tension? Is there enough bend in the mast?

-Will (Dragonfly)
 

JRT

.
Feb 14, 2017
2,037
Catalina 310 211 Lake Guntersville, AL
How do you adjust batten tension? Mine are all full and seem shoved all the way in the slot with velcro on the leech.

This is a good learning experience for me, I like the idea of a raised clew cut foot sail as mine is also close to the bimini.
 
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Oct 19, 2017
7,732
O'Day 19 Littleton, NH
Not all battens can be adjusted. The ones that tie into the pockets can be tightened with the tie strings. If yours drop into the pockets, it may require slightly longer battens wedged in tighter.

-Will (Dragonfly)
 
Jan 22, 2008
763
Hunter 340 Baytown TX
How do you adjust batten tension? Mine are all full and seem shoved all the way in the slot with velcro on the leech.

This is a good learning experience for me, I like the idea of a raised clew cut foot sail as mine is also close to the bimini.
The battens on my Quantum main have a screw on the end that adjusts the length. I will try to remember to get a photo when I adjust them. Not sure how it works, I think it moves the batten end cap.
I offered a copy of the manufacturer's sail plan to the sailmaker who made my main and jib. He said he didn't need it, would get his own measurements. The main was a foot short, too long on the boom, and the clew was way lower than the original. He did add a panel to increase the height, but that just screwed up the sail. The jib has never been right, either. He did come out on the bay with me and look at all the problems. Said there was nothing they could do about it, because the boat didn't have a backstay. Like I kept that a secret from him or they had never made sails for a B & R rigged Hunter of that era.

H340.JPG


This Hunter sail plan shows how the boom should angle up to give the arch plenty of clearance.
I have the rig tuned and checked annually by a local company that seem to be expert with B & R rigs. I've got a good 4 to 5" of prebend and the leeward shroud doesn't show slack until pushing hard in 15 to 20 knots apparent or so. I'm always telling the crew, "when in doubt, let it out". If I let the main out too much, it's backwinded by the jib. I let the jib out far enough to not backwind, I lose the telltales and the jib luffs. A 340 with standard main is tough to trim and balance upwind. The jib is only 108% and the 16' boom and big roach puts a lot of sail area aft, so you have to keep the jib driving hard to minimize weather helm. I keep the main halyard and the cunningham tight to keep the draft forward to help balance, but that makes it even easier for the jib to backwind the main. But, on reaches, she's very easy to trim and sail. The sail plan works better with the roller furling main rig.
I have looked back at photos from the last year or so, and the leeward curl started small and has been getting worse, like something is stretching or fabric is failing.
 
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Oct 19, 2017
7,732
O'Day 19 Littleton, NH
Said there was nothing they could do about it, because the boat didn't have a backstay.
What the |-|€|_|_ has that got to do with fixing a bad sail? Was he suggesting that B&R rigs can't be correctly fitted for sails?

-Will (Dragonfly)
 
Jan 22, 2008
763
Hunter 340 Baytown TX
What the |-|€|_|_ has that got to do with fixing a bad sail? Was he suggesting that B&R rigs can't be correctly fitted for sails?

-Will (Dragonfly)
Well, for the right price they can. They wanted more money than I thought I should have to pay to make the sails right that I had already paid for. They knew I was pretty dissatisfied and probably wouldn't be buying any more sails from them so they lost interest in my business. The sails came from Singapore or somewhere and I thought were actually well made and have some nice details on them. I'll see if I can get the leech issue solved without a recut and some stitching has been coming loose. Next set of sails will come from a loft that will make them locally, we've got four or five sail lofts around the bay.
 
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Jan 19, 2010
12,362
Hobie 16 & Rhodes 22 Skeeter Charleston
There are some sail lofts that will work on other people's sails. I have had great interactions with Bacon Sails out of Annapolis. If you call them, don't bother with the crispy jokes.... they have heard them already.:biggrin:
 
Jan 11, 2014
11,321
Sabre 362 113 Fair Haven, NY
The battens on my Quantum main have a screw on the end that adjusts the length. I will try to remember to get a photo when I adjust them. Not sure how it works, I think it moves the batten end cap.
The Bainbridge Batten ends have this sort of arrangement. The end of the batten fits into the car and rests against an aluminum bracket. . The screw is threaded into this bracket, when the screw is tightened, the bracket moves aft which increases the the tension on the batten, increasing the draft on that batten. This only works for the full length battens on the sail.


The jib has never been right, either. He did come out on the bay with me and look at all the problems. Said there was nothing they could do about it, because the boat didn't have a backstay. Like I kept that a secret from him or they had never made sails for a B & R rigged Hunter of that era.
It is way past time to find another sailmaker. Take it back and make him fix it. It is only cloth, if it is cut right and sewn right it will fit.