Adjusting Fully Battened Mainsails Compared to Standard Battened Mainsails + Vectra

[flaming]

Out of interest, is adjustable mast bend not required to vary sail fullness (camber) at the top of a fully battened sail? Relevant because OP has a masthead rig, while a number of replies are from those with fractional rigs.

Not really I think...

What bending the mast really does is flatten the middle of the sail and open the leach profile.

In general the reason full battened sails are great on cruising boats is because they provide bags of power and are very stable. Why they are not used on conventional racing boats is because they are very difficult to depower. This isn't such a big deal to the cruiser, you just drop a reef in. But racers are about to turn the corner and go downwind so want the full area available without all the power. Hence being able to flatten the sail is a much bigger priority.

For cruising I would absolutely always specify a fully battened sail.

For the OP.

My questions are: from a performance point of view, over variable wind strengths, does fully battened hold it's shape well? Do you still tweek halyard tension for camber position, or is it hard set by the full battens? Do you have to adjust batten tension or is it set when the sail is rigged. Can you change the depth of camber on a fully battened sail? Vectran is it the best way for a polyester sail longitivtiy before going to a laminate. Those who have changed from standard to full length battens and have done so for some time now, do you see performance maintained over a long period?

Camber profile (as distinct from amount) is still set with halyard tension. You can still use a cunningham to flatten the bottom section, but it has less effect than you are used to. Camber amount is largely preset with batten tension. After many thousands of miles underneath my Dad's fully battened cruising laminate main that in practice I never bothered adjusting batten tension, just left it at a sort of medium tension. The main "tweaking" I did was to play with twist a lot more than we do racing. And in general to use more twist than I started out with. I suspect that this also had a lot to do with the shallow keel that was fitted to the boat, but might be worth bearing in mind.
I saw very little change in performance profile over the 10 years I sailed that boat. Though it's fair to say that when sold that main didn't have an awful lot left in it.

 

[Deleted member 36384]

.... I saw very little change in performance profile over the 10 years I sailed that boat. Though it's fair to say that when sold that main didn't have an awful lot left in it.

How old was the sail? My sail maker does claim longevity and holding shape well for most of it's life compared to standard battens.

Question regarding de-powering: I sail a lot, onto / off moorings and anchors, around close quarters, fast de-powering is sometimes required without changing course e.g. sheeting out, dumping the kicker or even scandalising. Will de-powering be significantly effected with a fully battened sail?

 

[flaming]

How old was the sail? My sail maker does claim longevity and holding shape well for most of it's life compared to standard battens.

Question regarding de-powering: I sail a lot, onto / off moorings and anchors, around close quarters, fast de-powering is sometimes required without changing course e.g. sheeting out, dumping the kicker or even scandalising. Will de-powering be significantly effected with a fully battened sail?

Sail was new with the boat. It did a lot of mileage. Was still basically fine shape wise, good in fact, but had the leech rebuilt. I'd have been looking to replace it reasonably soon if we'd kept the boat.

Depowering is done differently. It requires halyard tension for the battens to take their proper shape, so dump a foot or so of halyard and you kill all drive out of the sail with the wind forward of the beam. Dumping the kicker and sheet can also work, but the effect is lessened. But the halyard dump is such an effective way of depowering that you soon learn to just use that. Done that a lot sailing onto buoys myself.
And if you need power it's 5s of winch work to get the halyard back on.

 

[Deleted member 36384]

..... the halyard dump is such an effective way of depowering that you soon learn to just use that. Done that a lot sailing onto buoys myself.
And if you need power it's 5s of winch work to get the halyard back on.

I never would have thought about using the halyard. Sorry to ask another question flaming: the four reefs, worth it or not, I have the lines on the boom, so not an issue regarding hardware? The Rival likes a bit of power for her hull to punch through waves, as opposed to ride over them, she also can carry a bit too much weather helm when pressed. My opinion is that the 4 reefs would be an advantage at wind speeds where reef 1 is still a bit much area but reef 2 is too much area reduction. Alternatively, do you think that a quality roller reefing headsail would negate 4 reefs in favour of the standard 3 reefs.

Once again, thanks to everyone for the information.

 

[flaming]

I never would have thought about using the halyard. Sorry to ask another question flaming: the four reefs, worth it or not, I have the lines on the boom, so not an issue regarding hardware?

If I answered that it would be nothing more than a guess...

 

[dom]

24.1 sq. m.

Leaving aside the sail/4th reef for a moment; is that really right, for a 10t 41ft boat?

 

[Deleted member 36384]

If I answered that it would be nothing more than a guess...

Okay, thanks for the previous information you have offered . Quandary stated in a thread from a few years ago, for a Hanse, that there was merit in smaller reef areas at the expense of the 70% reef, as he would never sail the boat in serious winds.

Leaving aside the sail/4th reef for a moment; is that really right, for a 10t 41ft boat?

33.91 sq. meters, from the official sail plan drawing. The sailmaker took the area from a previous mainsail he made for the boat (different owner). Mmm, need to check.

 

[dunedin]

One point i would disagree with your sailmaker on - I would want a cunningham hole on the sail. North know a few things about fast sails, and our North fast cruising sail has one. Even with the halyard bar taught, we find it useful to apply some cunningham upwind between 10 knots apparent and when we put in reef 1.
Hugely easier to apply and release without releasing the sheet/kicker etc, as would be needed to tighten the halyard (even if this were possible).

Also, whilst we have added a third reef to both our previous boats (which has been a huge improvement, and used extensively), I would doubt that a 4th reef would be worth the extra complexity and masses of rope - unless like Skip Novak you intend to got to the southern oceans / Antartica regularly.

A foam luff on the genoa is of course essential for any sort of performance upwind when reefed.

Enjoy your new sails - on a "sailing boat" having great sails should be near top of the priority list

 

[westhinder]

I never would have thought about using the halyard. Sorry to ask another question flaming: the four reefs, worth it or not, I have the lines on the boom, so not an issue regarding hardware? The Rival likes a bit of power for her hull to punch through waves, as opposed to ride over them, she also can carry a bit too much weather helm when pressed. My opinion is that the 4 reefs would be an advantage at wind speeds where reef 1 is still a bit much area but reef 2 is too much area reduction. Alternatively, do you think that a quality roller reefing headsail would negate 4 reefs in favour of the standard 3 reefs.

Once again, thanks to everyone for the information.

BoB, your Rival gets most of its power from the Genoa, I think. I know my R34 did and I do not think yours (a 38?) is that different.
That’s why I would not get too hung up on the 4 reefs. I would always specify a genoa with a good foam luff, so that you get good shape and good drive from your genoa with a few rolls in. A genoa that is too full or baggy can also lead to excessive weather helm.
My Rival had a conventional mainsail, but when I bought my Starlight I got a fully battened which I replaced with a new fully battened. I find three reefs enough, although I have to add that I accepted my sailmaker’s suggestion to increase the amount by which the sail can be reefed. The reefs are proportioned evenly.
You will probably notice as I did that new sails give such a better shape, that you have more power, less heel, less weather helm and hence reef later.

 

[lw395]

....

Depowering is done differently. It requires halyard tension for the battens to take their proper shape, so dump a foot or so of halyard and you kill all drive out of the sail with the wind forward of the beam. Dumping the kicker and sheet can also work, but the effect is lessened. But the halyard dump is such an effective way of depowering that you soon learn to just use that. Done that a lot sailing onto buoys myself.
And if you need power it's 5s of winch work to get the halyard back on.

To depower like this, the topping lift is on?
I sail dinghies with FB sails. Depowering to stop the boat is not an issue. With the kicker eased , the sail will sit very calmly with the top half backwinded. When you get back in a boat with a 'soft' sail, it seems flappy and unstable when eased to slow down or hove to.

 

[lw395]

One point i would disagree with your sailmaker on - I would want a cunningham hole on the sail. North know a few things about fast sails, and our North fast cruising sail has one. Even with the halyard bar taught, we find it useful to apply some cunningham upwind between 10 knots apparent and when we put in reef 1.
Hugely easier to apply and release without releasing the sheet/kicker etc, as would be needed to tighten the halyard (even if this were possible).
.....

Many loose footed sails don't exactly use a Cunningham, they use a downhaul.
The tack is not fixed to the boom, it is on a slider in the luff track or tied around the mast.
It's used as you say, like a cunningham on a conventional sail, just without the redundant bit of cloth between the cunningham and the boom.
So I would suggest clarifying with the sailmaker whether he is talking about a sail designed to be used llike this or not.

 

[flaming]

Many loose footed sails don't exactly use a Cunningham, they use a downhaul.

That would be extremely unlikely on a cruising sail.

 

[flaming]

To depower like this, the topping lift is on?
I sail dinghies with FB sails. Depowering to stop the boat is not an issue. With the kicker eased , the sail will sit very calmly with the top half backwinded. When you get back in a boat with a 'soft' sail, it seems flappy and unstable when eased to slow down or hove to.

A dinghy FB sail is a very different beast. It's a lot stiffer.

In this case the topping lift doesn't do anything except ensure you don't drop the boom on the driver's head when you dump a foot or 2 of halyard,

 

[lw395]

A dinghy FB sail is a very different beast. It's a lot stiffer.

In this case the topping lift doesn't do anything except ensure you don't drop the boom on the driver's head when you dump a foot or 2 of halyard,

So the leech goes slack and loses all power a bit like scandalising?
I would have thought if you dropped the halyard just a foot and the boom dropped with it, you'd get a lot of fullness in the front of the sail and not really depower it.

A dinghy FB sail is indeed fairly different, athough they cover a fair range. A Solo sail is quite different from say a B14 sail. Years ago I had Solos with dacron sails and stiff masts.
But like the only FB yacht sails I've used, I've found they 'idle' in a fairly benign way compared to flappy soft sails when you're waiting or going alongside or whatever.

Personally I would be wary of an FB sail with no effective downhaul/cunnngham arrangement.

 

[flaming]

So the leech goes slack and loses all power a bit like scandalising?
I would have thought if you dropped the halyard just a foot and the boom dropped with it, you'd get a lot of fullness in the front of the sail and not really depower it.

No, with no tension in the halyard there is nothing to compress the battens so the shape in the sail just goes.

 

[dom]

Just read the opening post; couple of comments:

1. Notwithstanding the sail measurement question, even at c.35m^2 this is a modestly powered boat and the OP mentions the need for lightwind spd. In such circumstances the sailmaker shld have asked how the boat sails, in particular wrt weather helm. Boats of this age will be powered in accordance with design, available materials, cost, and a lack of accurate aero- and fluid-dynamic software. In other words the optimal high-modulus FB main today might be significantly different to your current sail (esp wrt roach), though this will partly be a fn of weather helm. Even if the boat has some weather helm it might still be sensible to add more roach as the drive of a FB sail will certainly move forward. It may also be possible to adjust mast rake, rig tension, etc.

2: A FB main puts significant compression loads on the luff boxes and good ones are expensive to spec. Hanses for example, esp the bigger ones, tend to have underspecced track gear and I've seen a system blown during a F4 gybe. It is imperative that this gear is up to scratch as it's a an expensive PITA to upgrade later. The fact that you are thinking of 4x reefs suggests you are none too timid.

3. Re boat-handling/de-powering the main - it's true that FB sails are tricky in the sense that the flow is inclined to suddenly go from stalled to laminar causing the boat to either shoot fwd or suddenly stop. You will get the hang of it.

4. Finally, the 4th reef: this will basically be a trisail reef and my guess is on such a sized mainsail/boat you'll never use it - and probably never even rig it, save in F8+ to F8++ conditions. (BTW IMHO and many others, boomless trisails are hopeless!)​

All in, my guess is that you'll find a way to craft a wonderful new sail that maximises your enjoyment of the boat and lasts for years. There are lots of useful options at the higher-end of this market, so be sure to harness them and optimise the all-important holistic balance between sails, rig, and boat! And with no pesky class rules to box you in, you have a free hand to boot :encouragement:

 

[Deleted member 36384]

Everyone, your information is really appreciated and has provided valuable input into my decision making process. Clearly I need to have detailed discussions with the sail maker who finally gets the order so that I get what is required.

As always, thanks for your time to reply.

Cheers,

BlowingOldBoots.

 

[Deleted member 36384]

To Close Out The Thread

I ordered a fully battened mainsail, Vectran material, Rutgenson 'Batcar' system, 3 reefs, cunningham and flattener, loose footed. Top reef is 60% luff length and the the remaining two reefs and cunningham / flattener will be spaced to suit the batten cars. I kept the cunningham and flattener not for these traditional functions but simply because as a reef point I have the fittings / lines all run in the boom (slab reefing system: reefing pennant and rams horn) and I may as well use them as they are permanently rigged.

Also ordered a new furling genoa, Vectran as I got a very good deal at SIBS. At some future point I'll add a smaller furling genoa and ghoster to complete my wardrobe.

Once again, thanks for your input, very valuable.

 

[Quandary]

Okay, thanks for the previous information you have offered . Quandary stated in a thread from a few years ago, for a Hanse, that there was merit in smaller reef areas at the expense of the 70% reef, as he would never sail the boat in serious winds.



33.91 sq. meters, from the official sail plan drawing. The sailmaker took the area from a previous mainsail he made for the boat (different owner). Mmm, need to check.

What Quandary was talking about was his Finngulf, (Hanse??? Moi???) typical Baltic hi aspect rig with fully battened North Finland sail running in a Selden ?? section mast specifically designed for the cars. It had three reefs but after the first season we never rigged the third one and very rarely used the second. This is mainly because if forty knots are expected I try to be somewhere sheltered with the sails down, If you don't race and rarely do more than 10 hr. passages there is no need to go out in that sort of weather. Ist reef 18-20 kts upwind, second was fine above 25 or so.
But you are only a lad with a heavy boat and a more compact rig. FWIW I don't think you need four reefs though.

 

[zoidberg]

There's something to be said for the thinking that went into this.....

He, his sail and spar-makers are 'walking the walk'.