New sail configuration

Oct 24, 2010
2,405
Hunter 30 Everett, WA
We are considering new sails (certainly overdue) on our 1989 Hunter 30 (tall skinny mast).
I'm trying to figure out if I want a luff flattener (115%) with a UV strip, and a new loose footed main.

We don't race, but I'd like a sail that will hold it's shape.
I'm also considering raising the jib up to clear the bow pulpit and possibly allow some visibility under the headsail. Yes, I'm looking at SBO as the supplier. They are great folks and support the best sailing forum on the web.
What would you order?

Ken
 
Jan 11, 2014
13,006
Sabre 362 113 Fair Haven, NY
If you have a roller furler, you most definitely want a UV strip. Without the UV strip you will be buying a new head sail in a couple of years.

Are you asking about the luff foam for the jib? The purpose of the foam is to allow the sail to be reefed and still maintain a reasonable shape when furled. These are particularly useful on 150% headsails that need to be furled to 135 or 110. The question to ask is how often do you furl a 115%? Is reducing sail by reefing the main and keeping the jib full a reasonable option for the sailing you do?

Raising the tack of the headsail above the pulpit is going to affect sail trim. Another option is to have the sail cut with a higher clew, but leave the tack at or near the deck. This will improve visibility and have less effect on sail trip. It will also not trap water that comes over the deck.

Talk to the sail maker, about the options.
 
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SG

.
Feb 11, 2017
1,670
J/Boat J/160 Annapolis
I wouldn't cut a sail up that high. You'd be better-off with a slightly higher clew. You'll give-up a lot of performance and really encourage weather helm, in my opinion.

Also the cut of the sail would really have to be a lot different -- so I'd talk with a sail designer/maker who you can rely upon before I did did that.
 
Mar 1, 2012
2,182
1961 Rhodes Meridian 25 Texas coast
UI use a pennant on mine to raise the foot.. Sail is also cut high,, but I've gotten in trouble with a low cut jib, sailing short handed. Not safe to not be able to see to leeward.

rail-down-small.jpg


Another angle

Tehani-Oct-29-large.jpg
 
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Feb 26, 2004
23,054
Catalina 34 224 Maple Bay, BC, Canada
Hi, Ken,

Mine is a standard C34 110% that I installed high off the pulpit by purchasing a ProFurl furler with long link plates. I have found no impact to the sailing ability of the boat. Indeed, I find it much safer. What you need to consider is where the jib fairlead tracks are and how that works with your clew, so talking with your sailmaker certainly wouldn't hurt.

I have an 85 and a 110. I haven't reefed either one. Your boat, your choice :) on whether you feel it's necessary on a 115, and on your boat. IIRC, you're a fractional rig, so would have different characteristics than my masthead rig when it comes to wanting or needing to reef the jib, as your mainsail would be your "driver" more than mine is. I often sail without the main upwind and do quite well.

No question about the UV, don't leave home (or your boat) without it! :)

A loose foot would be cool, just make sure your outhaul is nice and smooth.

Happy Thanksgiving to you both.

Stu
 
Aug 13, 2012
533
Catalina 270 Ottawa
No question about the UV, don't leave home (or your boat) without it!
No question, but consider not using the heavier Sunbrella, but rather a sacrificial Dacron strip (or another UV protective material). The sail shape should be better, especially in light winds.

Marek
 

Rick D

.
Jun 14, 2008
7,186
Hunter Legend 40.5 Shoreline Marina Long Beach CA
You can consider a window in the jib if you single hand a lot in crowded conditions. I had one on two boats.
 
Oct 24, 2010
2,405
Hunter 30 Everett, WA
Thanks for the responses.

My boat has the furler below deck so the jib is literally at deck level. When sailing, the bow pulpit destroys sail shape for the bottom few feet. With that in mind, I don't think I get any benefit from that part of the sail.

I was thinking of shortening the luff just to reduce the interference from the pulpit.

As for the "luff flattener", I posted that question because I didn't know what it is.

I will definitely see what I can learn from the sail folks.
Ken
 
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Jan 11, 2014
13,006
Sabre 362 113 Fair Haven, NY
As for the "luff flattener", I posted that question because I didn't know what it is.
The luff of a sail is not a straight line. It has a convex curve in it. The larger the sail, the larger the curve. The Headstay is a straight line until the sail is raised and is full, then it takes on the curve of the headsail, this is usually referred to as headsail sag. If designed well, this makes the sail faster. The sail is also not flat, there is more material in the forward end of the sail, that gives the sail its shape.

Because of the curve and the extra material to give the sail shape, when the sail is furled there is more material in the middle than at the ends. The foam luff or luff flattener, makes the furled sail fatter in the middle than at the ends to take up the extra material used for the curve. The goal is to try and give the new luff (once partially furled) a decent shape.

Boats with above deck roller furling have the tack about 8" to 12" above the deck. Raising the tack on your boat a similar amount will probably have negligible negative impact on sailing performance especially when compared to the effect of the pulpit on sail shape. To raise the tack attach a short pendant made of a high tech line, like dyneema, or a section of SS wire. The luff of the sail should remain the length, unless it is already the length of the forestay.

If the headsail is already as long as it can be, shortening the luff by 2 feet will significantly reduce the size of the sail which will significantly reduce performance. It may cause other issues. If the goat is to keep the size of the sail at 115% of the foretriangle, then it would need a longer foot. That will affect sheeting angles and the standing rigging may get in the way, especially when trying to go to windward. The pointing angle may be larger and/or there may be issues with the sail chafing on the rigging.

Sailing is all so simple, until its not. :what:
 
Feb 26, 2004
23,054
Catalina 34 224 Maple Bay, BC, Canada
If the goat is to keep the size of the sail at 115% of the foretriangle, then it would need a longer foot.
Dave, if you shorten the luff length and want to keep the sail at a 115, wouldn't the foot actually get shorter if the leech stays the same?

LP Headsail Percent.JPG
 
Jan 11, 2014
13,006
Sabre 362 113 Fair Haven, NY
Stu,

Yes, if you only calculate LP and do not consider the sail area. If you want to maintain the same sail area some dimension has to change.

The area of a triangle is ½ * base * height

For a sail the base = luff, and the height is the LP

Assume a 10' luff and a 10 LP

½ * 10 * 10 = 50 ft2

Now assume a luff 2 feet shorter, same LP

½ * 8 * 10 = 40 ft2

Shortening the luff while maintaining the LP causes a big hit in sail area. Sail area is important.

When messing around with foresails there is lots to be considered; sail area, sheeting angles, chafing, to name a few.
 

SG

.
Feb 11, 2017
1,670
J/Boat J/160 Annapolis
The two dimensional drawing the Stu posted above are useful as exhibits; however, the sail isn't flat (as others have noted).

As others have discussed, the sail isn't simply a triangle, it's a part of the shappable wing which should provide LIFT, it has a different center of work depending of shape, angle of the apparent wind, wind speed, pitching, etc., etc.

If it makes no material difference how one cuts the foot out of a sail, why don't you think every race boat would do that?

[It's not just tenth of a second a mile. It has to do with pointing ability, drive on reaches, heeling of the boat, etc., etc. If those things make a difference to you, then I'd really consult with a sail maker. If its just que sera, sera, then just clip away :^))). I don't intend to be pejorative, just an observation. The difference may not be noticeable for any number of reasons -- have little to do with polar charts or weather helm.
 
Feb 26, 2004
23,054
Catalina 34 224 Maple Bay, BC, Canada
Yes, if you only calculate LP and do not consider the sail area. If you want to maintain the same sail area some dimension has to change.
I agree. However, IIRC, Ken said he wanted a 115. That's why I posted that dwg. Yes, I know sails are curved. But that dwg is one of the best I've seen explaining LP, and it is pertinent.
When messing around with foresails there is lots to be considered; sail area, sheeting angles, chafing, to name a few.
Absolutely, and is what I suggested to Ken, especially the sheeting angles from the clew to his jib track/fairlead looking at it from the side of the boat. Of course, it applies looking down, too, but I would think that wouldn't change much since the forestay and track remain in the same place. :)
 

Rick D

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Jun 14, 2008
7,186
Hunter Legend 40.5 Shoreline Marina Long Beach CA
Long before you consider doing that, you need to consider exactly what issue you are trying to solve. My furler is also below deck, so the jib is near-deck level. It isn't a sweeper, but very close to it. I did have a window installed in my older sail and it did help with day sails with short handed crew in congested conditions. When I had a new sail made, I didn't get the window. Frankly, I don't miss it that much to make me add one.
When you are close-hauled, to you bring the foot inside the lifelines? You should and should be able to. That ends the issue with the foot over the pulpit. On a reach, the sail will lay over the pulpit, but it isn't an issue. In fact, the only issue I have is when furling and the pulpit will tend to put a wrinkle in the lower section in some situations. The fix is simple; I simply redo it back at the dock or mooring. So, my advice is that, if it was really that good an idea, you would see a lot more boats with jibs cut that way. Good luck whatever you decide!
 
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Jul 1, 1998
3,062
Hunter Legend 35 Poulsbo/Semiahmoo WA
After reading the above (came in late), here are my thoughts:

1. Jib luff length: Find out what the fuller manufacturer has to say about the angle the jib halyard has to make between the swivel and the mast sheave. In the case of the OEM Hood furler, they have a specific angle range.

2. Jib clew height: When the jib is furled it would be a good idea to have it not higher than you can reach, and the height will be a few feet higher than when the jib is deployed. See Stu’s diagram in post #10. The height of the brown(ish) LP line where it meets the fuller should (hopefully) be reachable by standing on the deck.

3. Pulpit: Personal opinion here: I don’t think it matters much if the jib shape is altered a bit by the pulpit because when sailing close hauled and sheeted in tight any shape change is minimal and when way off the wind it will be forward of the pulpit. For the in-between angles I don’t think it’s a big deal ‘cuz like you say, you aren’t racing. If chafe is a concern (no problem on our boat), put some UV material in that area. [Edit: just read Rick's post above on this subject]

4. Sail cloth weight: For the cloth the sail maker will use, the weight will be determined by the sail dimension. In my case I went with the next heavier cloth weight to hopefully increase longevity. The good news: It really worked! After 20 years with thousands of miles under the keel in all kinds of weather the sail shape is, what can I say, marvelous. Really, really good. Have sail-shape pictures from when the sails were new and they’re still excellent. I do take the sails off at the end of the season to prevent mold (that’s what we get around here, right?) but, still, the shape is great.

5. Tall fractional rig: One reef in the main and you gotta masthead rig.

6. Loose foot: The sailmaker asked if I wanted it but I was hit broadsided so kept the bolt rope setup. In hindsight the loose foot would make it easier to take the sail off and put it on again. However, as was mentioned by Stu again (this guy has a lot of good comments), make sure the outhaul is nice and smooth. My boom has a block inside to provide mechanical advantage and it’s a tad harder to pull the outhaul out but helpful if one want’s to winch the clew in tighter.

7. Flatening reef: Make sure the spreader patches cover the area between the non-flattening and flattening reef areas. Heck, maybe even with the first reef in, too, but I don’t reef much off the wind. 40 knots down the Strait of Juan de Fuca, wa-hoo! with a full main!!! Riding the flood from Barkley Sound to Sooke Inlet, could have gone all the way to Port Townsend but had to take a break.

8. Full battens: Wouldn’t go with a full bottom batten again. Not worth the hassle.

9. Jib: Back to this sail again; wouldn’t go too high off the deck with the tack, currently it’s only about six to eight inches, and clew height, wouldn’t go with a Yankee cut again either. Maybe two or three feet but not more. Can’t say that the Yankee cut has ever helped with visibility to justify it. Since the furler is below deck make sure the tack pendant won’t interfere with the steel plate of the anchor roller setup.

9. Mast bend: Make sure the sail cut takes into account the mast bend of the rig and also discuss the fuller sag dimension. Weather helm was discussed earlier and aside from sail shape and dimensions, how the rig is tuned, like mast rake, affects the helm.

10. Main sail: Level boom or raise the clew? If I had to do it over again I’d raise the clew a bit to give more headroom. There’s a good reason why the boom is called the boom! Also, could give a bit more clearance for the dodger (this is the Northwest - we don’t use biminis).

11. Jib UV strip: This is not an option. The typical UV material tends to shrink over time and will cause a hook in the leach, not nice for the picky sail trimmer (c’est moi!). North sewed mine on flat and last year it was removed and new UV put on. HOWEVER!; they used a sticky-back material without mentioning it to me. Asked them what happens when it’s time to replace it and was told to buy a new sail. Between you and me, and everyone else here, that jib is still in really good shape (and they agreed). If that happens I’ll be looking at a different sailmaker.

12. Draft stripes: Nice to have. They can put them on or you can do it yourself. Take pictures when the sail is new.

13. Leach adjustments: Find out what will be used to determine if you like the setup.

That’s all I can think of at the moment, but: “The devil is in the details.” (and there are lots of 'em)
 
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jssailem

SBO Weather and Forecasting Forum Jim & John
Oct 22, 2014
23,251
CAL 35 Cruiser #21 moored EVERETT WA
@Stu Jackson
Using your drawings, instead of changing the locations of the Clew, change the location of the tack along the luff. I think that is what Ken is suggesting and still get a 115% sail.. Just off hand the sail would take on more of a genoa appearance with a longer foot thus pushing the clew aft. This would affect the sheet angles identified by @dlochner .
 

Joe

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Jun 1, 2004
8,204
Catalina 27 Mission Bay, San Diego
Basic geometry.... the Luff of the sail is the "base" of the triangle. The LP of the sail is the "height" of the triangle (in a "right" triangle the sides are the height.. being perpendicular to each other already) Therefore the AREA of the sail is 1/2 LxLP (Base x height). A sail's size is expressed as a percentage of its area compared to the area of the boat's fore triangle (which, btw, is a "right" triangle.... foredeck length x max hoist (at mast).....
The shortcut, therefore, is to compare a Sail's "LP" to the Boats "J".... try it the long way if you choose.... but it is correct. A 115 jib's LP will be exactly 15% longer than the boat's "J"

So.... if you shorten the luff to raise the tack off the foredeck... you must lengthen the LP to maintain the same sail area. As long as the L and LP relationship remain constant, manipulating the foot and leech length will determine the clew's height above deck, but not affect it's area ... from Deck sweeper to Yankee. It is very common for cruising boats to have higher clewed, raised tack headsails.... because they provide better visibility, are easier to handle, and capture less green water.
 
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Oct 24, 2010
2,405
Hunter 30 Everett, WA
I knew I should post this here.

John Nantz pointed out (I think correctly) that close hauled is when sail shape is most important. I guess I should put the headsail back on and take a closer look at what I have.

I was thinking if the leach length remained the same, with the same angle between the leach and luff, and the clew raised (shortening the luff) that the sheet position should be about the same as the original sail. If memory serves me I normally sail with the jib car about a foot or foot and a half from the aft end of the track. A smaller sail would still leave me with plenty of jib track, as it would just move the car forward. The great pictures Charlie posted are what I had in mind (although I do have a fractional rig.)

I'm also way too excited to see what a new set of sails can do for me. I suspect the ones I have in place are original from 1989 and I've been putting up with them for 3 seasons.
Much appreciation to those who chimed in.
Ken
 
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Jul 1, 1998
3,062
Hunter Legend 35 Poulsbo/Semiahmoo WA
I'm also way too excited to see what a new set of sails can do for me.
You have no idea!!!

I suspect the ones I have in place are original from 1989 and I've been putting up with them for 3 seasons.
It'll be like having a new boat, but without the cost of one. No more knockdowns in a little puff.
Edit: Disclaimer, I have no association with any sail loft.
 
Jan 11, 2014
13,006
Sabre 362 113 Fair Haven, NY
I was thinking if the leach length remained the same, with the same angle between the leach and luff, and the clew raised (shortening the luff) that the sheet position should be about the same as the original sail. If memory serves me I normally sail with the jib car about a foot or foot and a half from the aft end of the track. A smaller sail would still leave me with plenty of jib track, as it would just move the car forward. The great pictures Charlie posted are what I had in mind (although I do have a fractional rig.)
The sheeting angle will be roughly an extension of the LP. Extend the the line created by the jib sheet on to the sail, it should bisect the angle formed by the leach and foot. This puts roughly equal tension on the foot and leach, which in most conditions is the correct trim. When the height of the clew changes, it will change the jib sheet lead angle, the lead will have to move aft to achieve the same angle. How much depends on how high the clew is raised.

If I had paid more attention in Geometry 50 years ago I could write the proof that demonstrates this, but alas, I didn't.