Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 15-09-2016, 14:39   #1
Registered User
 
lindabarzini's Avatar

Join Date: Jan 2016
Posts: 140
How to fill leech of sail

The leech of my mainsail just doesn't seem to hold air. When close-hauled in 10-15kts of breeze, most of the mainsail holds a nice full curve, but as the sail reaches the roach area, it starts flapping.

I can't figure out if the main halyard or outhaul needs more tension (it is an in-mast furling North Sail) or if the sail itself is simply blown-out (9-years old).

What is the best method to fill the leech/roach part of the sail for maximum lift?
__________________

__________________
lindabarzini is offline   Reply With Quote
Old 15-09-2016, 14:52   #2
Senior Cruiser

Cruisers Forum Supporter

Join Date: Aug 2009
Location: between the devil and the deep blue sea
Boat: a sailing boat
Posts: 16,571
Re: How to fill leech of sail

It is an odd question. The way you put it, there can be a number of challenges. And so a number of good solutions.

Can you take a picture of the sail showing the problem?

b.
__________________

__________________
barnakiel is offline   Reply With Quote
Old 15-09-2016, 15:25   #3
Senior Cruiser
 
Jim Cate's Avatar

Cruisers Forum Supporter

Join Date: May 2008
Location: cruising SW Pacific
Boat: Jon Sayer 1-off 46 ft fract rig sloop strip plank in W Red Cedar
Posts: 10,323
Send a message via Skype™ to Jim Cate
Re: How to fill leech of sail

Since it is an in-mast furling sail, it probably does not have any roach at all (unless equipped with vertical battens, which you did not mention). That being the case, the symptoms you describe indicate that the leech area is badly stretched, and either a recut or replacement will be required to cure the ailment.

Jim
__________________
Jim and Ann s/v Insatiable II back in Pittwater again.
Jim Cate is offline   Reply With Quote
Old 15-09-2016, 16:03   #4
Registered User
 
Panope's Avatar

Join Date: Sep 2012
Location: Washington State
Boat: Colvin, Saugeen Witch (Aluminum), 34'
Posts: 1,484
Re: How to fill leech of sail

Does this sail have a leech string?

Steve
Panope is offline   Reply With Quote
Old 15-09-2016, 16:06   #5
Moderator
 
Don C L's Avatar

Join Date: Sep 2014
Location: Channel Islands, CA
Boat: 1962 Columbia 29 MK 1 #37
Posts: 3,274
Images: 27
Re: How to fill leech of sail

yes, tighten the leech line.
__________________
DL
Pythagoras
1962 Columbia 29 MKI #37
Don C L is offline   Reply With Quote
Old 15-09-2016, 16:06   #6
Registered User
 
Training Wheels's Avatar

Join Date: Aug 2014
Location: Left coast.
Posts: 588
Re: How to fill leech of sail

Quote:
Originally Posted by Jim Cate View Post
Since it is an in-mast furling sail, it probably does not have any roach at all (unless equipped with vertical battens, which you did not mention). That being the case, the symptoms you describe indicate that the leech area is badly stretched, and either a recut or replacement will be required to cure the ailment.

Jim

^^^This!
__________________
Training Wheels is online now   Reply With Quote
Old 15-09-2016, 16:17   #7
Registered User

Join Date: Jun 2013
Location: Cruising
Posts: 97
Re: How to fill leech of sail

1- Tighten leech line
2 - You're overtrimming. Ease traveler & vang a bit, tighten halyard & outhaul.
3 - Vertical battens?
4 - Recut

Personally, I envision this as an outhaul problem. For going upwind, I'd crank on the outhaul and make that sucker as tight as can be. No battens means it'll be tough regardless, but not impossible. I can see your roach curling wildly if the mainsheet is super tight, traveler centered, halyard tight, but outhaul loose.

Otherwise, tell your local loft and they'll take some extra canvas out of that leech.
__________________
vmattiola is offline   Reply With Quote
Old 15-09-2016, 16:38   #8
Marine Service Provider

Join Date: May 2012
Location: New Orleans
Boat: We have a problem... A serious addiction issue.
Posts: 3,823
Re: How to fill leech of sail

Jim is right, but if you can tighten the leech line it will help a bit. Eventually the leech line has to be pulled so tight it starts to cup, at which point it's probably better (faster at least) to let it flutter.
__________________
Greg

- If animals weren't meant to be eaten then they wouldn't be made of food.
Stumble is offline   Reply With Quote
Old 15-09-2016, 17:07   #9
Senior Cruiser

Cruisers Forum Supporter

Join Date: Aug 2009
Location: between the devil and the deep blue sea
Boat: a sailing boat
Posts: 16,571
Re: How to fill leech of sail

Quote:
Originally Posted by Stumble View Post
Jim is right, but if you can tighten the leech line it will help a bit. Eventually the leech line has to be pulled so tight it starts to cup, at which point it's probably better (faster at least) to let it flutter.
Oooops. IMHO, do not let anything flutter. Flutter kills the leech tape area.


b.
__________________
barnakiel is offline   Reply With Quote
Old 15-09-2016, 18:19   #10
Registered User
 
Panope's Avatar

Join Date: Sep 2012
Location: Washington State
Boat: Colvin, Saugeen Witch (Aluminum), 34'
Posts: 1,484
Re: How to fill leech of sail

Quote:
Originally Posted by Panope View Post
Does this sail have a leech string?

Steve
I hope that when I asked the above question, no one thought I was countering Jim's assessment.

I do not know anything about marconi rigs.

I am genuinely curious:

Do all modern main sails have leach strings?

Do "roachy" mains have leech strings?

Do Full batten mains have leech strings?

Steve
Panope is offline   Reply With Quote
Old 15-09-2016, 18:23   #11
Registered User
 
Sandero's Avatar

Join Date: Apr 2006
Location: Southern Westchester/Northport LI
Boat: Shiva - Contest 36s
Posts: 4,250
Re: How to fill leech of sail

You should have a leech line in a pocket sewn into the leech which a cleat at the bottom As yoy tension the line you introduce a "curl" or tension into the leech.

Your leech is not straight and so as you tension it... it will take a curved shape. You want the entire sail to be a smooth continuous curve (air foil) with the tell tales on the leech streaming aft not curling or drooping.

Not a great pic but you can see the leech line pocket and at least one telltale streaming properly... and of course the curve of the leech.
Attached Thumbnails
Click image for larger version

Name:	IMG_5902.jpg
Views:	139
Size:	402.6 KB
ID:	131221  
__________________
Sandero is offline   Reply With Quote
Old 15-09-2016, 19:06   #12
Registered User
 
UNCIVILIZED's Avatar

Join Date: Jun 2014
Location: Up the mast, looking for clean wind.
Boat: Currently Shopping, & Heavily in LUST!
Posts: 4,428
Re: How to fill leech of sail

The guys have already nailed down many of the issues, & their possible fixes. However if you have battens, you might try increasing the tension on them via the pocket closure system, if possible. It'll stiffen up the sail's roach by a wee bit, for a time.

Plus, if you can tension your battens, then you might also look at putting a stiffer set of them into the sail. Or laminating some S-Glass or Carbon onto them to stiffen them up. In addition to trying the adding tension to them trick.

And does this problem at all get better if you ease the Traveler a bit, while taking in on the Sheet slightly. Or vise versa? It's worth a try anyway. Though yes, I know, odds are it has been.


Panope, to answer your questions. All of them are yes, for the most part.

On the leech cord tightening, for those unfamiliar with what it is, & the terms used to define it, & it's effect. Cupping is when the cord's tightened enough so that the leech line pulls the loose fabric at the sail's trailing edge into a small "cup" type hook/pocket in the sail, with the cup (pocket) facing to weather/upwind. So that there's a big air brake on the sail's trailing edge. Which kills much of the smooth flow on the aft portion of the sail, sometimes significantly reducing it's production of lift.
__________________

The Uncommon Thing, The Hard Thing, The Important Thing (in Life): Making Promises to Yourself, And Keeping Them.
UNCIVILIZED is online now   Reply With Quote
Old 15-09-2016, 21:19   #13
Senior Cruiser
 
Jim Cate's Avatar

Cruisers Forum Supporter

Join Date: May 2008
Location: cruising SW Pacific
Boat: Jon Sayer 1-off 46 ft fract rig sloop strip plank in W Red Cedar
Posts: 10,323
Send a message via Skype™ to Jim Cate
Re: How to fill leech of sail

Quote:
The guys have already nailed down many of the issues, & their possible fixes. However if you have battens, you might try increasing the tension on them via the pocket closure system, if possible. It'll stiffen up the sail's roach by a wee bit, for a time.
Unciv, it is a in-mast furling main... hard to increase batten tension when there are no battens!

Jim

PS I dunno if such sails usually have leech cords or not. With no roach, one could cut hollow (reverse roach) into the leech, and that tends to stop flutter... possibly even as a retrofit cut in this case, and that would not be expensive to do.
__________________
Jim and Ann s/v Insatiable II back in Pittwater again.
Jim Cate is offline   Reply With Quote
Old 15-09-2016, 22:32   #14
Registered User
 
UNCIVILIZED's Avatar

Join Date: Jun 2014
Location: Up the mast, looking for clean wind.
Boat: Currently Shopping, & Heavily in LUST!
Posts: 4,428
Re: How to fill leech of sail

Jim, there are in mast furling mains which have battens. The battens are just vertical instead of horizontal is all. Much as are found on some jibs now as well, even RF jibs. But the mains had them first.
__________________

The Uncommon Thing, The Hard Thing, The Important Thing (in Life): Making Promises to Yourself, And Keeping Them.
UNCIVILIZED is online now   Reply With Quote
Old 15-09-2016, 22:42   #15
Marine Service Provider

Join Date: May 2012
Location: New Orleans
Boat: We have a problem... A serious addiction issue.
Posts: 3,823
Re: How to fill leech of sail

Quote:
Originally Posted by Panope View Post
I hope that when I asked the above question, no one thought I was countering Jim's assessment.

I do not know anything about marconi rigs.

I am genuinely curious:

Do all modern main sails have leach strings?

Do "roachy" mains have leech strings?

Do Full batten mains have leech strings?

Steve
About the only sail where you won't see them at all is high end racing sails because by the time you need it the sail is getting replaced. All the leech line does is trim out stretch in the sail fabric, so for cruisers and club racers they can get more time between buying new sails. Basically unless you are going to buy a new sail evey 6-12 months they are a really good thing to have.

Eventually the sail is just too stretched out and instead of preventing the sail from fluttering it pulls a hook or cup in the leech. At which point even club racers should be buying replacements.
__________________

__________________
Greg

- If animals weren't meant to be eaten then they wouldn't be made of food.
Stumble is offline   Reply With Quote
Reply

Tags
sail

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Want To Buy: Wanted: ATN Spinnaker Sock for 44' Leech SalishCraig Classifieds Archive 0 27-07-2011 09:36
For Sale: Used Storm Trysail (or Trisail) Luff 24' Leech 26' Foot 15' feathercrafter Classifieds Archive 0 12-05-2010 20:01
For Sale: Doyle Kevlar Racing Sail 63' Luff, 62'5" Leech, 31'3" Foot feathercrafter Classifieds Archive 0 12-05-2010 19:56
Lines From Leech To Topping Lift Moonchaser2304 Deck hardware: Rigging, Sails & Hoisting 12 12-04-2009 19:55
Leech line problems Jim Cate Deck hardware: Rigging, Sails & Hoisting 23 25-03-2009 09:43


Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 11:10.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.