flapping leech

[Bertolt55]

I'm new to this game and have a question about a constantly flapping leech in my mainsail. It flaps regardless of wind position and sheeting, and regardless of whether I have the sail reefed or not. Have I got something very basic wrong in my set up, or has the sail had its day? The boat is a 1979 Anderson 22. I've no idea how old the sail is. Any help much appreciated!

 

[Wansworth]

The mythical Anderson 22………ask a sailmaker probably need a new main

 

[Biggles Wader]

I cant see a kicking strap holding the boom down. Has it got one?

 

[dunedin]

Sometimes sails have an adjustable leech line - a thin nylon string/rope threaded through the back edge of the sail. If so you could try tensioning that a bit more.
Also, it looks like the boom needs to be pulled down more - using a tighter kicking strap (aka boom vang)

 

[Bertolt55]

Thanks for the replies! I did the kicking strap on a while ago, but didn't think it made any difference. I will try it again and maybe tighter. Not sure if there is a leech line on the sail - I'll check next time I'm on board.

 

[MoodySabre]

It looks like a leech line just the bottom batten in that video.
the sail is reefed but is the aft reefing line pulled tight enough?

 

[VicS]

Thanks for the replies! I did the kicking strap on a while ago, but didn't think it made any difference. I will try it again and maybe tighter. Not sure if there is a leech line on the sail - I'll check next time I'm on board.

Maybe need a more powerful kicker ? but the boom is so low that its is difficult to get a kicker to be really effective when close hauled

Cannot see your mainsheet but when close hauled in a strong wind setting the traveller fully to leeward and tightening the mainsheet a little will pull the boom down more effectively than a weak kicker.

 

[Norman_E]

With the sail reefed its hard to see if there is a leech line, but if there is one then it needs a bit more tension. A tensioned leech line goes some way towards controlling fluttering, but cannot fully deal with effects of stretching in an old sail. Its not unknown for the fitting that holds the leach line to fail. It happened to me once, but a sailmaker quickly sewed on a new one.

 

[Refueler]

Leech lines .... worst bit ever added to any sail. So many people overtighten - then when boom tensioned down by sheets / kicker - a 'hooked leech' is created ...

Fluttering leech - actually indicates near clean flow of the sail ... its same as a piece of paper held in wind ... the trailing edge flutters.

 

[jamie N]

The topping lift seems to be tight.

 

[Refueler]

The topping lift seems to be tight.

Yep ... well spotted

 

[greeny]

The topping lift seems to be tight.

And if so, no amount of kicker will pull the end of the boom down. Other question I have is whether the leech flutters with the sail fully raised i.e. no reef. Also, remember that If there's a leechline fitted it will need adjusting when the reef is set in the sail because its anchor/adjusting point is level with the reef cringle thats being used at the time

 

[greeny]

Leech lines .... worst bit ever added to any sail. So many people overtighten - then when boom tensioned down by sheets / kicker - a 'hooked leech' is created ...

Fluttering leech - actually indicates near clean flow of the sail ... its same as a piece of paper held in wind ... the trailing edge flutters.

I agree but on some sails it's needed. Only the minimum to stop or reduce the flutter without creating a hook.

 

[steveeasy]

Your topping lift looks tight. The mainsheet should be able to tighten the leech. My sail flutters just in one place. im going to fit a leech line to see if it helps.
As for a kicker. Never use mine sailing upwind. May use it downwind but I’m not really a fan of the kicker or perhaps a little unsure of the benefits of its use.

steveeasy

 

[dunedin]

Your topping lift looks tight. The mainsheet should be able to tighten the leech. My sail flutters just in one place. im going to fit a leech line to see if it helps.
As for a kicker. Never use mine sailing upwind. May use it downwind but I’m not really a fan of the kicker or perhaps a little unsure of the benefits of its use.

steveeasy

The kicking strap is essential downwind to stop the sail twisting too much at the top. And on a run, excess twist can cause a “death roll” effect, which needs the kicker on to stabilise.

 

[Spirit (of Glenans)]

Thanks for the replies! I did the kicking strap on a while ago, but didn't think it made any difference. I will try it again and maybe tighter. Not sure if there is a leech line on the sail - I'll check next time I'm on board.

You need to adjust your kicking strap frequently, to suit the conditions and point of sail.
It doesn't need to be particularly tight when close-hauled or close reaching, as the mainsheet will be having more effect, but should be progressively tightened the more you come off the wind. When you are broad-reaching or running, the mainsheet is not pulling the boom down, this is when you should have the kicking strap at its tightest.

 

[Spirit (of Glenans)]

Your topping lift looks tight. The mainsheet should be able to tighten the leech. My sail flutters just in one place. im going to fit a leech line to see if it helps.
As for a kicker. Never use mine sailing upwind. May use it downwind but I’m not really a fan of the kicker or perhaps a little unsure of the benefits of its use.

steveeasy

When sailing downwind it flattens the sail as required. The mainsheet, being slack at this point of sail, will not be having a flattening effect. It helps to keep the sail correctly shaped.

 

[Spirit (of Glenans)]

I'm new to this game and have a question about a constantly flapping leech in my mainsail. It flaps regardless of wind position and sheeting, and regardless of whether I have the sail reefed or not. Have I got something very basic wrong in my set up, or has the sail had its day? The boat is a 1979 Anderson 22. I've no idea how old the sail is. Any help much appreciated!

Others have commented that your topping lift looks tight. I feel that I should expand on their statements by saying that the primary purpose of the topping lift is to hold the boom in a horizontal position when the sail is dropped, both to keep the boom out of the cockpit and to make it easier to raise the sail most of the way up by hand.
It should be slackened off considerably, once the sail is raised, to the point that the boom is solely supported by the sail, and that the wind is inducing a slight curve in the slackened topping lift, but not to the point that it can come in contact with the backstay.
Try this before any further experiments with the leech line and you will doubtless find that the flapping has stopped and that you are getting more drive from the sail now that it is no longer partially scandalised.
Edit: I should add that that when reefing, your first action, before releasing the kicking strap, is to tighten up about six inches on the topping lift, to take the weight of the boom, hence making it easier to apply full tension to the reefing line. Don't forget to slacken it off again after you have hardened up the halyard.

 

[William_H]

I agree with Nigel re leach cord. Horrible things especially in jib. I must say I have never adjusted leach cord in main despite having one for 43yrs. (many sails)Usually the battens will keep the leach stable on main. Definitely loosen topping lift. I always take mine off but it is not adjustable. Then as said if it still flutters pull down on main sheet. ol'will

 

[Refueler]

Leech line. Think about it ... leech of a sail is not a straight edge. It has a slight curve / form to it. When you tighten leech line - you force the leech to lose its form and hook to be straight.

Leech line IMHO should be adjusted to not have slack line, locked and left alone - so sail can set properly.

Topping lift - I like mine set so boom is supported when sail is down, when sail up - just enough slack so sail / sheet / kicker control boom and TL is not catching sail or backstay. I never have to adjust it.