Sail too long in the luff

[thinwater]

Originally Posted by Ssas5342

I have a sail off a Seawind 1000xl on my Seawind 1000 (extended to an XL) The sail is too long in the luff as the boom on the factory xl is a little lower on the mast.
I’ve attached the sail on what I assume is the Cunningham cringle, and it fits well.
I’ve noticed that the leech, or around 1/4 of the lower rear of the sail, is somewhat flatter than I would expect when under pressure. There’s a good belly in the sail and by tightening the top lift I can get some more shape towards the rear of the sail.
Apart from the obvious lowering the boom, (major surgery), does anyone have an opinion if this is caused by the sail being secured by the Cunningham cringle or is there a way to get a better sail shape?

When the outhaul is tight, the lower 1/4 of the sail should be flat. This is to avoid backwinding from the jib upwind. Did you try loosening the outhaul (you didn't say)? The shape problem, if there is one, is probably related to trim, not the wrong grommet locations. But by all means, have the foot of the sail renovated, as others have suggested. How complicated this is depends on how far it needs to be moved, though if the cunningham hole works, I'm guessing not far.


Is the sail truly at full hoist (look at it from down the dock)? There could be something preventing full hoist, like a fat splice and excess hardware. You could try just tying the sail on with a halyard knot or similar. This may get you 3-6 inches more hoist.

[onestepcsy37]

just one more thing.

i had taken my 'too long in the luff' to a sailmaker to shorten it at the head. having done that, if i had more time than money, i could have done a half decent job on it myself. so if you are in to saving a few dollars and have the time i don't think the process is all that difficult.

1. figure how much sail you need to cut off at the head.
2. remove the existing headboard.
3. measure (twice!!), mark, and cut (once!!) the sail head off. use a square held against the luff to make sure you mark a straight line.
4. seal the cut edge with a cigarette lighter or any other method
that will keep it from fraying.
5. make a new headboard. not hard. use aluminum or thin starboard
or any other light, stiff, waterproof material.
6. attach the headboard.

just a suggestion....

[Ssas5342]

Originally Posted by thinwater

When the outhaul is tight, the lower 1/4 of the sail should be flat. This is to avoid backwinding from the jib upwind. Did you try loosening the outhaul (you didn't say)? The shape problem, if there is one, is probably related to trim, not the wrong grommet locations. But by all means, have the foot of the sail renovated, as others have suggested. How complicated this is depends on how far it needs to be moved, though if the cunningham hole works, I'm guessing not far.


Is the sail truly at full hoist (look at it from down the dock)? There could be something preventing full hoist, like a fat splice and excess hardware. You could try just tying the sail on with a halyard knot or similar. This may get you 3-6 inches more hoist.

Yeah, tried all those. Hauling up on the top lift helped a bit of shape. The sail is definitely all the way to the top.

[Ssas5342]

Here are some photos of the sail with a Cunningham on the first reef point. There are some vertical crinkles I’m not happy about.
Still looks too flat towards the leech to me.

[fxykty]

That is not a flat leech, that’s inverted. And there is no way those battens should be inverting like that if the sail is in decent condition.

The inversion could be because you are not tensioning the sheet enough - does the cabin top restrict the amount you can pull the boom down? If that’s the case, the sail has to be shortened - the suggestion to do it at the head is preferable if the top batten can handle the shortened luff and greater load. If not, shortening at the bottom is reasonably simple - though it will need a lot of strengthening at both clew and tack (as a cunningham is not designed for foot loads - the tack does that job even when the cunningham is loaded).

If you are tensioning the sheet correctly, then the leech is stretched to sh*t and the sail is no good.

[Tupaia]

Sorry, based on your picture the sail is past it sell by date, even the cross cut seam is showing distortion above and below. Tightening up the leach lines and using stiffer battens may improve it a little but not worth spending the money unless you have some battens laying around.

[Rucksta]

I'd be looking at increasing the sail tension on the battens and clearing those lines that are fouling the area that is too flat / inverted.

Then make the decision to trash or modify the sail.

There are two or three seams that could be re-stitched while you are at the sailmakers for a new headboard or foot chop.

This may produce a reasonable sail for another season while you assess the requirements for a new sail.

Another measurement that may be contributing to the poor shape is luff cut for mast pre-bend.
It looks like you have to much cut for the amount of pre-bend.

Guess based on incomplete information.

[Gary Mc]

I hate to say it but that is one ugly sail.
It was poorly made and has seen much abuse. The leech is badly stretched out, something that should not happen like that with full battens if the sail was properly made. The battens are likely not stiff enough
The luff should have additional main slides between the full battens and I would say that the Dacron was too light for the use this sail has seen.
If a new sail is out of the question now, you need to take it to a decent sail maker and have them do what they can with it.
Good Luck

[Sailmonkey]

I’ll echo, the leech is either not tight enough (sheet) or the sail is shot.

I’m leaning towards a sail that is done. Don’t spend a dime on it.

[smj]

If I remember correctly the original Seawind 1000 mainsails were known to have the dreaded S curve, which this one seems to have a bad case of.

[Rucksta]

Originally Posted by Gary Mc

I hate to say it but that is one ugly sail.

Totally agree; yet the leech tell tales are all streaming in spite of the pot belly around the CoE.

[Tupaia]

Originally Posted by Gary Mc

The luff should have additional main slides between the full battens.

This is poor advice for club footed mainsails, where the mast is raked and or the boom kicked up, typical on multihulls. The intermediates will cause jams when reefing because the perpendicular distance from the mast to the reef point is shorter than the distance from the goose-neck.

[Ssas5342]

Ok, so this is what I think might be happening. (Sensible corrections or discussion may follow)
The sail is too long in the luff as it appears the factory Seawind 1000 XL has a lower boom. The sail is currently held down by what I assume was a Cunningham cringle. Therefore, the whole geometry of the sail is out. The luff and leech are out of kilter. This being the case, the sail cut will never allow the leech to be tight as it will not give enough through the belly to allow the right shape.
Im off to see the sail maker today to ask his opinion. I’ll let you know how it goes.

[Ssas5342]

Originally Posted by Tupaia

Sorry, based on your picture the sail is past it sell by date, even the cross cut seam is showing distortion above and below. Tightening up the leach lines and using stiffer battens may improve it a little but not worth spending the money unless you have some battens laying around.

The battens are pretty stiff. I think the photos are exaggerating the flatness of the leech. I was also experiment with a few things so the shape could be as a result of that. As you can see, I’ve got it hauled down using the first reefing point. In the end, the following photo is what it’s really all about.

[wingssail]

Originally Posted by Ssas5342

The battens are pretty stiff. I think the photos are exaggerating the flatness of the leech. I was also experiment with a few things so the shape could be as a result of that. As you can see, I’ve got it hauled down using the first reefing point. In the end, the following photo is what it’s really all about.Attachment 232155

Attachment 232154

I am pretty impressed. I've never actually before seen a sail with a shape like that; I don't know how you did it (but if you look at the primary flight feathers of a large bird, they do have a shape like that, so maybe it's fast).

I think maybe you have too many things too tight.

Start over. Put the sail up to the first reef (both tack and clew reefing being used). Then haul the halyard just snug to take out the luff wrinkles, and then sheet in to close hauled and see what it looks like. Don't two-block anything!

If you still have that weird leech falling off, then I think the sail needs major surgery and it probably isn't worth it. If it looks OK then you will have an idea what it might be like with some taken off the foot or the head.