Inmast furler battens

[daletournier]

Hi all, before I start please don't turn this into a "inmast furlers a bad" type thread, only people with inmast furling experience reply. I'm very happy with my Sparcraft imast furling system.

I purchased a new mainsail 18 months ago. I'm not 100% happy with it. When 70 degrees off the wind or closer as the wind picks up I get significant leech flutter. I've tried everything but can't get rid of it.

I've never had jamming issues with this system, I get the sail in and out fast and with easy. Because of the type of sailing I do, at times I've had to get it in while things are going bad, therefore less than perfect conditions, it's never failed.

Now, I'm considering adding battens to the sail to help with the leech. My only concern is does this increase the risk of jamming? To me it seems it would. Do you have to be more careful?

Interested in opinions from those that have battens and sail in less than perfect conditions.

Cheers Dale.

[psk125]

We have friends with a r/f main whose battens, when improperly rolled, ripped holes in their sails and jammed in the spar. They didn't find out until they went to unroll the sail.... and couldn't. Not fun for them.

[AKA-None]

I think dockhead or boatman has an in mast furler, but I don’t recall which. And I think it also has battens but then I may be misremembering

[Oceansailor]

Originally Posted by daletournier

Hi all, before I start please don't turn this into a "inmast furlers a bad" type thread, only people with inmast furling experience reply. I'm very happy with my Sparcraft imast furling system.

I purchased a new mainsail 18 months ago. I'm not 100% happy with it. When 70 degrees off the wind or closer as the wind picks up I get significant leech flutter. I've tried everything but can't get rid of it.

I've never had jamming issues with this system, I get the sail in and out fast and with easy. Because of the type of sailing I do, at times I've had to get it in while things are going bad, therefore less than perfect conditions, it's never failed.

Now, I'm considering adding battens to the sail to help with the leech. My only concern is does this increase the risk of jamming? To me it seems it would. Do you have to be more careful?

Interested in opinions from those that have battens and sail in less than perfect conditions.

Cheers Dale.

First I think there must be something wrong with the design of your sail. If it is designed right you should not have any flutter. Go back to the sailmaker and tell him to do it right would be my first advice. What material was used? Did it flatter from day one?


If it is tight without battens, adding battens will make furling more difficult. How much sail you can furl in to the mast depends on available volume in the mast, length of the foot and weight and type of sail cloth.

On my own boat I have had 3 different main sails. I have plenty of volume in the mast profile. Battens are not a problem.

The one that was easiest to furl had 4 full length vertical battens and a very stabile laminate cloth.

My next sail had 4 partial length vertical battens (10-15 feet) and a hight tech woven cloth. This sail was marginally more difficult to furl.
I think full length battens are a better alternative as they reduce wrinkles when furling.

The third sail had no battens. This sail was a little bit trickier to furl as the sail cloth stretched over time. I’m sure vertical battens would have been an improvement on this sail.

The cloth is more important than battens when it come to how easy it will be to furl.

A stiff laminate without battens is probably the optimal, if ease of furl is the most important factor.

If you want more performance, a stiff laminate with battens allows for more sail area.

[Jim Cate]

Dale, it is Dockhead who has posted glowing reports of his carbon laminate sails with vertical battens. I'm sure he'd be glad to elucidate!

Jim

[Kenomac]

I’m the one who has vertical battens on two large mainsails with in mast furling, I’ve also posted a youtube video of the process on several threads... only to usually receive a bunch of negative, idiotic, spiteful, boneheaded replies on CF, so I’m not doing it this time.

So...

It works great, no jams in over eight years (if one knows what they’re doing)... you can expect jams if one’s an idiot and can’t follow directions or has never been shown how to use it properly with necessary pressure on the outhaul.

Our sails are Dolphin DYS with sailcoat which makes it even easier. We did on one occasion have one of the uppermost battens disappear when it worked its way out, so be sure to velcro and secure each one carefully, it was probably our mistake.

Yes the four vertical battens make a difference over having a somewhat blown out Dacron sails without battens prior to getting new sails. Our sails are tri radial cut Dyneema DYS with sailcoat and dynemma thread... not some special super duper model that would make our boat go too fast.

I hope this answers your question.

[Lost Horizons]

Originally Posted by daletournier

Now, I'm considering adding battens to the sail to help with the leech. My only concern is does this increase the risk of jamming? To me it seems it would. Do you have to be more careful?

My last boat had vertical battens on furling main. It jammed couple of times as I was learning how to work it. When properly furled in, it would not jam. The boat I am having built now will not have battens; the builder cited the very reason that battens increase risk of jamming. I am going with their recommendation.

Have you tried to eliminate the flatter by adjusting the leech tension or sail’s geometry?

[AKA-None]

Sorry Ken I forgot you had a battened main

[Dockhead]

I have heard multiple horror stories about battens on in-mast furling mains, but I trusted my sailmaker and ordered them on my new carbon mainsail 5 years ago. I have 4 of them, and they are thin carbon fiber rods (not epoxy or plastic).



I've never had the slightest problem with them in furling, and they are brilliant at improving sail shape, and they allow a straight leech which has a much better shape than battenless hollow leech. The furler doesn't even notice them going in and out.



I guess YMMV depending on the type of in-mast furling system, and perhaps the type of sailcloth is also important. Perhaps the shape or thickness of the batten also influences performance in in-mast furling.



I would suggest reliance on a really good sailmaker who will take responsibility for the results.


My furling system and mast is by Selden, which is the more or less universal type in Northern Europe. The slot in the mast is quite wide which probably makes a difference.


But I guess it also makes a difference how the pockets are designed. Mine open only DOWNWARDS, so the tops of the pockets -- where they touch the slot in the mast first -- are sewed shut and can't catch. I did have problems with the battens falling out despite the elaborate velcro system my sailmaker made and I ended up sewing them shut at the bottom too.

[Dockhead]

Originally Posted by Kenomac

. . . . We did on one occasion have one of the uppermost battens disappear when it worked its way out, so be sure to velcro and secure each one carefully, it was probably our mistake.. . .

I had battens fall out several times, and I finally just sewed the pockets shut at the bottom.


It was probably NOT your mistake, but an inherent problem, so you might consider doing this too.

[daletournier]

Thanks for all the replys. I'm heading to Trinidad in 4 weeks time, will work with a sail maker there to solve the problem.