Flappy Mainsail Leech

Fire99

Fire99

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Evening folks,

A wee question for you. Was out sailing yesterday and saw that my Mainsail Leech seemed pretty flappy on a beat. (Snapdragon 23) . Is there anything that can be done to 'trim' this out (if it needs it of course)?

Thanks,

Nik
 
Fire99 said:
Evening folks,

A wee question for you. Was out sailing yesterday and saw that my Mainsail Leech seemed pretty flappy on a beat. (Snapdragon 23) . Is there anything that can be done to 'trim' this out (if it needs it of course)?

Thanks,

Nik
Click to expand...

First - was your topping lift fully free? Next, do you have a boom vang/ kicking strap & was it fully tightened. Finally, try tightening your leach line a little if you have one.

Fluttering of the leach is not unusual if beating well, it is due to the turbulance caused by the wind slipping off the back of the sail, you might try easing the sheet a little (but not enough for the luff to lift) and see if that helps.

Snappies are lovely old cruisers but are seldom set up to sail like racers! She will respond to being kept full & by rather than pinching. Point too high & she will slow down & crab off to leeward.
 
Thanks for that. Yep, Kicking strap was tight. I don't think my mainsail has a leech-line, which posed my question (since I read about them in sail trimming books etc)

I tend not to try pointing too high. (May I add the '23' won a race back in the day. Won it's class doing a round Britain. True story.. Irrelevant to this but I liked it. :D )

I do like to try and get the best out of what I have.. Why not..
 
Mainsail leeches do tend to get stretched, and this can be worse if they haven't been properly handled. I don't think the flapping itself affects performance much but it shortens the life of the sail and can be very irritating. Many mains need a little tightening of the leech line, but not enough to make the sail curl, especially as the wind strength rises. My main has done about 18,000 miles and is OK except when reefed, when some tightening of the leech helps.

You could "trim it out" I suppose, by yanking hard down on the kicker, but this would take all the twist out and spoil the performance. The leech should make a graceful aerofoil-like curve from masthead down.
 
johnalison said:
Mainsail leeches do tend to get stretched, and this can be worse if they haven't been properly handled. I don't think the flapping itself affects performance much but it shortens the life of the sail and can be very irritating. Many mains need a little tightening of the leech line, but not enough to make the sail curl, especially as the wind strength rises. My main has done about 18,000 miles and is OK except when reefed, when some tightening of the leech helps.

You could "trim it out" I suppose, by yanking hard down on the kicker, but this would take all the twist out and spoil the performance. The leech should make a graceful aerofoil-like curve from masthead down.
Click to expand...

Thanks for that. I'll take another look tomorrow. It may just be that the sail is somewhat past its prime.. :)
 
I detest flappy leeches. You seem to have a boom-end mainsheet so I guess there aren't many options left to you.
Sail may be knackered.
 
The big question is whereabouts on the leech is it flapping?

If it is nearer the head of the sail you can try reducing the twist in the sail. Close-hauled you'd do that with the traveller & mainsheet more than the kicker. Adjust the traveller so that the mainsheet is pulling the boom down more directly.

That said, it may well just need the leech line pulled on. I'd be surprised if there isn't one. Usually you adjust them by swinging from the boom by one hand whilst trying to get the line to stay in that damned jammer with the other :) If you really don't have one already, get them to fit it such that you can adjust it at the tack end of the mainsail (i.e. runs up the leech then down the luff to the cleat) as it cuts back on the acrobatics to adjust it. Take the chance to get leech telltales too so that you can gauge the twist of the main easier.
 
Fire99 said:
Evening folks,

A wee question for you. Was out sailing yesterday and saw that my Mainsail Leech seemed pretty flappy on a beat. (Snapdragon 23) . Is there anything that can be done to 'trim' this out (if it needs it of course)?

Thanks,

Nik
Click to expand...
I assume all your battens are in place, and long enough. Pulling down a mainsail by the leech instead of the luff is a frequent cause of stretched cloth there - could be someone before you did not know this.

You may not have a leech line on a 23 ft boat....
 
dt4134 said:
Usually you adjust them by swinging from the boom by one hand whilst trying to get the line to stay in that damned jammer with the other :) If you really don't have one already, get them to fit it such that you can adjust it at the tack end of the mainsail (i.e. runs up the leech then down the luff to the cleat) as it cuts back on the acrobatics to adjust it. Take the chance to get leech telltales too so that you can gauge the twist of the main easier.
Click to expand...

I've never seen a leech line arranged like this. Does it run over a small block at the head? How does it work with 1 or more reefs in?
 
DaveS said:
I've never seen a leech line arranged like this. Does it run over a small block at the head? How does it work with 1 or more reefs in?
Click to expand...

Yes there's a small block at the head. With a reef in you can adjust it at the various points at the luff just as normal. There'll be separate cleats at the right height on the luff for each set of reefing point. Not sure how it is handled at the leech but presumably there is some strengthening to stop the leech line damaging the sail where it is flaked on the boom.

I've mainly seen it on racing laminate mains where there is no acceptable option but to stop the leech fluttering, even in conditions where you wouldn't want to put a crew member at risk to adjust a leech line at the leech. In heavy weather a fluttering leech can destroy a laminate mainsail in as little as 15 to 20 minutes.
 
dt4134 said:
There'll be separate cleats at the right height on the luff for each set of reefing point. Not sure how it is handled at the leech but presumably there is some strengthening to stop the leech line damaging the sail where it is flaked on the boom.
Click to expand...

Yes, it was what happens at the leech when there's a reef in that was puzzling me. When reefed the part of the leech below it is not tensioned. I suppose that friction in the flakes might give a sufficient anchor for the line, but is seems a bit iffy.

I hadn't realised laminate sails were so fragile. Another reason to avoid, methinks. :eek:
 
Well gang. Good news and bad news. Bad news is that I don't have a Leech line. I've checked, felt and fumbled but no line exists.

However, giving the kicker a good pull, whilst pulling down on the boom, did seem to improve things a little.

In summary, I think it's just something I'll have to suffer until the sail is changed.

Maybe a nice 2nd hand sail will turn up soon, whilst finances are stretched somewhat.
 
DaveS said:
Yes, it was what happens at the leech when there's a reef in that was puzzling me. When reefed the part of the leech below it is not tensioned. I suppose that friction in the flakes might give a sufficient anchor for the line, but is seems a bit iffy.

I hadn't realised laminate sails were so fragile. Another reason to avoid, methinks. :eek:
Click to expand...

Don't let me put you off laminates. They are far easier to trim to an efficient shape. They can make cruising laminates more long wearing than lightweight racing sails (taffeta on either side of the laminate helps a lot) but there are like anything high tech and do need looking after by a knowledgeable user. It's the same with anything else: you might abuse an old monkey wrench by using it as a makeshift hammer but you wouldn't do that with your sextant.
 
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