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Old 04-04-2013
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Sail Cut & Shape

Need your opinion. What is good and not so good about this sail shape/cut?

Rehoboth Bay/Indian River, DE
S/Y KJ, Helms 25
1976 #552
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Old 04-04-2013
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Re: Sail Cut & Shape

The two lower battens are either not tapered or are inserted backwards. There shouldn't be a sharp ridge at the front of them.

No roach.

I don't get what's going on at the foot of the sail. Is the halyard fully raised? Is the downhaul pulling the boom all the way down? Is there enough tension on the reefing lines to prevent full hoist of the sail?

The draft is pretty far back, which also implies light halyard tension.

It looks like you have a lot of vang on (or it's very light air and no topping lift), which is closing the leech of the sail.
boats that I sail on regularly: Pearson 28-2, Rondar 505, Yankee 30, Blanchard Junior
Seattle, WA
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Old 04-04-2013
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Re: Sail Cut & Shape

Are you trying to find issues with how the sail is made, or with how you are trimming it?
Orange Crush
1974 C&C27 MkII

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Old 04-04-2013
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Re: Sail Cut & Shape

Go out in at least 5 kts of wind, trim the sail for upwind work and take a picture looking from the mid boom location up to the masthead. Then post the picture.

Looks like a new sail. Something you don't like about it?
Merit 25 # 764 "Audrey"
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Old 04-04-2013
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Re: Sail Cut & Shape

Your leech is 'hooked up' to weather; leech is too tight from either too much mainsheet pressure (or vang pressure); or more probably, the sail isnt sufficiently 'raised' (not enough mainsail halyard tension after raising). Could also be your reefing clew lines are too tight.

My suspicion is insufficient halyard tension (or insufficient cunningham tension). The Helms 25 has a mainsail luff dimension of approx. 25 ft. so when 'raising' the main, get it 'up' and then add an additional 2 to 2-1/2" of luff stretch via extra halyard, etc. tension so that the sail takes on the 'designed' dimensions that the sailmaker intended. Once you get this proper luff/boltrope tension, put marks on the halyard and a corresponding mark on the mast so when you 'raise' and 'stretch' you be at close to proper tension and 'stretched out' luff dimension every time. You have to 'stretch out' the luff on dacron sails made with luff 'boltropes' ... otherwise they will set with a 'hooked up' leech and will be 'draft aft' --- only good for extreme 'weather helm' and very aggressive heeling ;-).

The tack angle (the angle that the top of the boom makes with the mast when the sail is 'properly raised') for a Helms 25 main is 88°

Here's how to properly raise a 'boltroped' dacron mainsail: How to properly RAISE a woven dacron mainsail -

The H25 is fairly quick and lightweight boat so a more forward draft position and more 'rounded' luff shape (a 'speed shape') from higher halyard tension will be of benefit, especially when sailing 'fast'. The 'rounded' shape of the luff section will be 'more forgiving' in 'variable wind and boat speeds' .... use extra outhaul tension when doing this to keep the 'amount' of draft a bit 'minimized'.
When you get the luff tension correct, those diagonal small creases ('girts') radiating from the clew to the middle of the luff will probably disappear.
You also need to 'lubricate' your mast track.

Last edited by RichH; 04-04-2013 at 10:44 AM.
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Old 04-04-2013
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Re: Sail Cut & Shape

Thanks for all the great input.
I'm trying to get a better shape and no wrinkles.

Probably about 8 knots in this shot,~ 50 degree to wind.

This rig has a mast claw and halyard crimp in the SS cable part of the halyard. Tension is by the downhaul at the adjustable gooseneck on the mast track. There is no mechanical advantage there and you just have to push down on the boom at the gooseneck as hard as you can and cleat the downhaul line. Doing this, the luff seems bango string tight, but maybe still not enough.

The vang is loose in this shot.

It is a loose foot sail using slugs on the luff boltrope.

No topping lift on this rig. Just a 2' clip line on the backstay for the end of the boom.

Reefing lines had no tension, not cleated.

The bottom two battens concerned me also. They came that way from the sailmaker and I don't think they are tapered at either end, but I'll check again. The sharp ridge at the front of the battens can be reduce by more outhaul, but then I have very little draft.
The sailmaker did give me a smaller diameter second from the top full batten to get a better shape, but the top round batten has no bend unless it's blowing 15 kts.

Sail is a few years old with not many hours on it.

Jeff, thanks for the link. Very informative.
Rehoboth Bay/Indian River, DE
S/Y KJ, Helms 25
1976 #552
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Old 04-04-2013
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Re: Sail Cut & Shape

The long wrinkle along the boom is caused by too much outhaul tension. You want to close off the shelf on your loose foot in a beat, but this is too much. A little more halyard tension will get rid of the puckers in the luff and will move the draft for you. Agreed, if you want to spend money, buy more flexible battens. Your top batten is way too stiff also. You have a lot of weight hanging on your leach in the form of the two reef lines. They look like 7/16? You can get by with smaller if that is the case. You can also do an ocean racer trick and tie a continuous loop (leaving a little pig tail) between the two reefing clews with some leech cord. That way reef 2’s clew line can be tied around the boom, taking weight off the sail. When you are in reef 1, you then reeve the second line through reef 2’s clew using your leach cord. We used to do this all the time with reefs 2 and 3 on the Areodyne.
George B
2000 Catalina 34 MkII
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Old 04-04-2013
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Re: Sail Cut & Shape

The first thing I want to do when I look at that pic is yank on the cunningham. You definitely need more luff tension. The top batten looks stiff, but more luff tension might force some shape into it. Right now the top has no shape at all. You could try to taper your bottom two battens yourself with a belt sander or something. (or just buy some!)

I am not convinced the wrinkles along the foot are from too much outhaul. The sail actually looks fairly full as it is. I was thinking more outhaul myself!
1979 Santana 30 Tall Rig
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Old 04-04-2013
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Re: Sail Cut & Shape

The wrinkles along the foot could also be the reef lines being a tad tight. Altho it really doesnot look like that is the issue personally. Tightening the halyard would be one of the first things to do or try.

Top batten as mentioned, also looks too stiff for that light of wind. I actually have two top battens, one light for up to 10-15 knots or so, the stiffer for when I know the winds will be above 15. An I literally will not put in a top batten if I am racing and feel the winds will be under 5-8 knots for that day/evenings race. If cruising I would install the light one for most cases.

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Old 04-04-2013
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Re: Sail Cut & Shape

How much flex should battens have...?

Can you measure it, ie: is there a chart that shows 24" batten requires 15# pressure to flex it 1" in the center...?

Which is stiffer wood or poly battens of the same size...?

On my sail 3 are poly and 2 are wood and they all feel stiff to me...??? Other that length, how do I know which one goes where...?
"Might as well cast off...If anything is gonna happen...It's gonna happen out there..."
"Captin Ron"
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