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Are Battens Really Needed?

Discussion in 'Sail Trim with Don Guillette' started by geehaw, Mar 19, 2018. Add this thread to a FAQ

  1. geehaw

    geehaw

    Joined May 15, 2010
    229 posts, 1 likes
    O-day 25 shoal keel
    US Valdez
    I bought a new mainsail. I got it from one of those Chinese sail houses. It is loose footed and no roach what so ever. So I was wondering if I needed the battens. The reason I ask is they are all only partial battens and the sail seems to fold where the battens start. The sail seems to make a “V” shape there rather then a nice round shape. So this makes it impossible to shape the main as the draft position always is right at the beginning of the battens or at least looks that way to me.
     


  2. kappykaplan

    kappykaplan

    Joined May 1, 2011
    717 posts, 92 likes
    Pearson 37
    US Lusby MD
    Photos, please.
     


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  3. Justin_NSA

    Justin_NSA

    Joined Jul 7, 2004
    4,402 posts, 620 likes
    Hunter 30T
    US Cheney, KS
    The battens should be complimenting the sail shape, not distorting it. It's possible that it wasn't cut right for your boat.
    The experts will chime in.
     


  4. Jackdaw

    Jackdaw

    Joined Nov 8, 2010
    8,306 posts, 1,756 likes
    Beneteau First 36.7 & 260
    US Minneapolis MN & Bayfield WI
    Are you sure it has NO roach at all??? Battens are absolutely needed on any sail that has any positive roach. This means sailcloth that is over the direct line between the head and the tack. Any such sailcloth cannot be tensioned by sail trim, and will flap uncontrollably when sailing unless the area is stiffened with battens. While this applies to most mainsails to some degree, it also applies to jibs.


    mainsail.jpg

    It might be that your battens are too stiff. Or in backwards if they are tapered.
     


  5. BobbyFunn

    BobbyFunn

    Joined Apr 16, 2017
    181 posts, 94 likes
    Hunter 170
    US Tampa
    Can we assume you have the halyard/downhaul taken care of, the outhaul snug and the boom vang tightened as needed?

    Battons could be too long. The mainsail doesnt really need so much draft that would not want to form a continuous line from leading to trailing edge.

    If all lines are tight and you cant get rid of that then id return sails or start thinning them out/shortening them.
     


  6. Jackdaw

    Jackdaw

    Joined Nov 8, 2010
    8,306 posts, 1,756 likes
    Beneteau First 36.7 & 260
    US Minneapolis MN & Bayfield WI
    Battens really can't be too long. Many sails have full battens. That can however be too stiff.
     


  7. Doug4bass

    Doug4bass

    Joined Jun 9, 2004
    563 posts, 46 likes
    Catalina 385
    US Marquette. Mi
    I have a loose footed furling Doyle with vertical battens. The main has a very small roach.
    Each year or so one batten has a habit of flying out the top of the pocket.
    You’ll know when a batten is missing by watching the leach go crazy.
     


    Last edited: Mar 19, 2018
  8. BobbyFunn

    BobbyFunn

    Joined Apr 16, 2017
    181 posts, 94 likes
    Hunter 170
    US Tampa
    The battons are probably too stiff, but,
    yes they can be too long. A full batten should be long enough to pretension shape like what they do to concrete by tensioning cables before it sets. Release the tension and the concrete compresses on itself. The batten should want to make a shape, giving in under normal loads to reverse itself.

    A batten that only goes part of the way is flawed, in that it doesnt want to take any shape other than flat. As soon as there is a difference in rigidity the surface fails at that weak point. This is where the flexibility parameter comes into play.

    The batton is too long if it does not contribute to a curved surface like a compressed full length batten. A partial batten should just be long enough to keep the leach from flapping, but at a point that is not anywhere near the max chord.

    I have a mainsail with both a full and 2 partials. I fully compress that upper full one so it has a shape even when there is no wind.

    The two partial lower battens go in pretty far for my taste, but i keep the outhaul and vang tight almost always. Otherwise, the mainsail folds at the end of the batten. They are very old granny pants sails.

    In model sail making, i found this out on day one of the first design with roach. My full length batten ruined the sails as they were just taped on=flat batten=flat sails. The partial battens need to just go past the "red line".
     


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  9. Jackdaw

    Jackdaw

    Joined Nov 8, 2010
    8,306 posts, 1,756 likes
    Beneteau First 36.7 & 260
    US Minneapolis MN & Bayfield WI
    Ah. you mean too long for the pocket. Agreed.
     


  10. mainesail

    mainesail

    Joined Sep 3, 2013
    15 posts, 0 likes
    Columbia 8.7
    US ROCKLAND & ST. PETE
    Actually, battens are NOT needed, BUT, the batten presence is designed or not designed into the sail. Some of the other replied go to some details, but not the core. Historically sails have had no battens. Eventually folks figured out that greater sail area, via the roach, could be added, but that area needed support, hence battens. A battenless design, generally has negative roach, ie. concave leach. A straight leach needs support, generally. Full length battens are just an extension of the original concept. I would highly recommend that you take the sail to your local independent sail loft to consult. I wouln't be surprised if other critical elements need attention. You kinda get what you pay for. Cheers.
     


  11. geehaw

    geehaw

    Joined May 15, 2010
    229 posts, 1 likes
    O-day 25 shoal keel
    US Valdez
    Thanks for replies. And to answer some questions. Yes there is no roach. No pictures boat won’t be in the water for a couple more months. I agree with mainsail I got what a paid for. I live in Alaska the closest sail loft is thousands of miles away. The batten are only 3/4” wide so have a hard time believing they would be to stiff. But what do I know? Kinda the reason I am here.
     


  12. mainesail

    mainesail

    Joined Sep 3, 2013
    15 posts, 0 likes
    Columbia 8.7
    US ROCKLAND & ST. PETE
    If you want, I'll put you in touch with a local sailmaker, here in Camden, Maine. Grant Gamble, he will absolutely treat you right, probably be worth the shipping..He does mostly read work, doesn't pop out racing sails. If your sail is fundamentally solid, a bit more should get you a nice battenles sail good for 10 years plus. Not sure about timing, but he has a very nice young woman apprenticing with him now. I'm at mainesail113@yahoo.com if you want to make contact... Cheers, Will
     


  13. shemandr

    shemandr

    Joined Jan 1, 2006
    3,257 posts, 423 likes
    Marblehead Skiff 14'
    US Greenport, NY
    I'm used to a tired mainsail having a crease where the battens end. As the sail stretches and the battens don't it is sort of inevitable. For a new sail I wouldn't want that. But the flat exit the battens provide are worth a lot. The worst is a hook on the leech of the mainsail which is total drag. In higher winds sometimes the main sail trimmer can only get the leech trimmed part of the time. Without battens there would be no chance.
     


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  14. JimInPB

    JimInPB

    Joined Aug 22, 2017
    579 posts, 161 likes
    Hunter 212 & 170
    us West Palm Beach
    I have thin stiff ones & I have very soft ones that are twice as wide & about 1.5 times the thickness. Dimensions & materials vary widely.
     


    DrJudyB likes this.
  15. DrJudyB

    DrJudyB

    Joined Jun 25, 2004
    141 posts, 65 likes
    Corsair F24 Mk1
    003 US San Francisco Bay, CA
    Yes, photos please.

    Shoot from under the middle of the boom up towards the head. Position the camera at 50% of the foot from tack to clew. Shoot with a mpmedium wide angle, Including as much of the leech and luff as possible. If you have a windex at the mast head, please show it in the picture.

    Please take the pic under sail, heading upwind on a close reach.
    Please estimate the wind speed.

    And don't over tighten the halyard, outhaul or vang.

    The aft third of the main should be flat with almost no curve.

    Judy B
    Sailmaker
     


    Last edited: Mar 27, 2018
    justsomeguy likes this.

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