Sailtrim question

[cliveshelton]

This weekend in a light wind on the east coast (lovely trip from Burnham to Walton backwaters) I noticed my mainsail exhibiting a rather distinct reverse curl along the clew. See attached image. Unfortunately the lighting is not good in the image but the top 2 battens are visibly "S" shaped and the others (2) are more pronounced if you could see them properly. The belly of the sail is too far forward and behind it the sail curls away along the clew. It is almost as if the battens are not stiff enough or perhaps not inserted well enough into their pockets to create the usual foil shape. However I have checked that there is no right and wrong way round to insert them (they are the same stiffness at both ends) and cannot really adjust them to create a permanent bend (they are held in with velcro).


View attachment 31525

Does anyone have an suggestions about the bit of string I should pull to create a better sail set?
Over to you and many thanks.

 

[sailorman]

This weekend in a light wind on the east coast (lovely trip from Burnham to Walton backwaters) I noticed my mainsail exhibiting a rather distinct reverse curl along the clew. See attached image. Unfortunately the lighting is not good in the image but the top 2 battens are visibly "S" shaped and the others (2) are more pronounced if you could see them properly. The belly of the sail is too far forward and behind it the sail curls away along the clew. It is almost as if the battens are not stiff enough or perhaps not inserted well enough into their pockets to create the usual foil shape. However I have checked that there is no right and wrong way round to insert them (they are the same stiffness at both ends) and cannot really adjust them to create a permanent bend (they are held in with velcro).


View attachment 31525

Does anyone have an suggestions about the bit of string I should pull to create a better sail set?
Over to you and many thanks.

that halliard looks wanged up
light winds, ease off halliard & outhaul to give a nice max draught about 1/3 > 1/2 from the mast

 

[emsworthy]

that halliard looks wanged up
light winds, ease off halliard & outhaul to give a nice max draught about 1/3 > 1/2 from the mast

+1

Halyard looks way too tight for light winds.

 

[bbg]

Looks to me like the reef line is too tight. That might be pulling the leech and causing the problem.

[pedant mode] clew is the aft corner of the sail. leech is trailing edge / side [/pedant]

 

[Seajet]

Check the leech line in the trailing edge of the mainsail ( if fitted ) is loose, not cleated too tightly.

If your clew outhaul is easily adjustable, playing with that, the kicker / vang and a slightly slackened halliard should give the desired shape.

Also check the topping lift is slack.

 

[dunedin]

Halyard over tension generally would not cause that issue.

As others have suggested check reef line and/or topping lift not too tight, as seems to be no tension up leech (back edge) of sail
We managed to get something similar recently when leeward lazy jack had hooked on end of a batten

 

[Twister_Ken]

Whack the vang on harder.

 

[saltylegs]

The reefing pennant is too tight (you can see the slack in the leech just below reef point) and the lazy jacks also appear to be taught, the halyard may also be too tight.
Ease all of the above and if draft is still to far forward then increase mast prebend, but I think if you address the above then all will be ok.

 

[Fantasie 19]

Looks to me like the reef line is too tight. That might be pulling the leech and causing the problem.

[pedant mode] clew is the aft corner of the sail. leech is trailing edge / side [/pedant]

+1 and also Seajets suggestion re topping lift...

 

[Champagne Murphy]

Light winds-genny pulled in a bit too much? We've found this can 'push' the main and bend it if the wind is too light to keep it everted

 

[sailorman]

Light winds-genny pulled in a bit too much? We've found this can 'push' the main and bend it if the wind is too light to keep it everted

"Back winding"

 

[Champagne Murphy]

"Back winding"

Bless you

 

[ProMariner]

It's a 'bum sail'

Some are born this way, some become this way over time. If you have a local friendly sailmaker, show them better pics, from under the foot looking up, and maybe get them to fit full tapered batons, if the sail is worth it. It will not fix it, but will reduce the effect.

Try a couple inches more mast bend, if you wish the sail flatter.

 

[BAtoo]

Does anyone have an suggestions about the bit of string I should pull to create a better sail set?
Over to you and many thanks.

Quite possibly pulled too many bits of string. In light winds (& most times when the boat won't "go") ease everything & start again gently.

 

[michael_w]

Looks a bit over sheeted too.

 

[onesea]

Ok I am not very good at sail trim and my dress sense is terrible (some say), but I have always thought of sails like clothes...

In this case I think you have a little to much tension in the worng places

Which is probably better than poorly cut sails or not enough tension in the right places:

It takes time to get the right tension to get the set just right:

Although when the wind pics up it might be worth tightening the strings

or you could end up with the thing go very wrong..

Some times easing sheets and spilling unexpected wind helps, makes an exciting ride and good spectator sport to...