Succinct instructions on flat sail building

  • 25 Jul 2019 20:45
    Reply # 7797134 on 7796692
    Anonymous wrote:

    I've been curious about Shirlz's decision to go back.  She cites two things:  she hated the baggy look, and the cambered sail required more maintenance.  And she's got more experience and capability than I'll ever have.

    1) In matters of aesthetic taste, there can be no arguments.  If someone doesn't like the look of their home, it can really wear on them.  I like the look of cambered sails and actually dislike the flat look.  I've spent too many years around airplanes and jet engines to see anything but drag and inefficiency in flat foils.

    2) Others have found that a camber sail doesn't necessarily lead to higher maintenance if particular steps are taken in the design. 

    It really would be so little effort to put some camber in.  But horses for courses.


    I don't get the worry about the baggy looking cambered sails.  If you wanna look at ugly, have a look at a typical pointy end rig cruising boat with some of the junk they carry on deck and aft.  Their boat looks like a floating chandlery.   
    A bit of bagginess in my JR rig until the wind fills in doesn't bother me.  Of course, purely an opinion, and each to their own :-)

    Last modified: 25 Jul 2019 20:47 | Anonymous member
  • 25 Jul 2019 20:41
    Reply # 7797114 on 7795562
    Deleted user

    Each of my sails sre about 370 sq ft. Do i need false seems in the panels.  Thanks

  • 25 Jul 2019 18:59
    Reply # 7797012 on 7796466
    Paul wrote:

    I would ask David Tyler to re post his excellent formula for  calculating the batten angle with cambered panels which works perfectly.

    Here you are, Paul.
  • 25 Jul 2019 18:40
    Reply # 7796985 on 7795562
    Deleted user

    Thank you Mr Tyler. That is exactly the help i was looking for, at least now i can get material ordered and a game plan in place. I will try and take your advice and go from flat to flattish. I like ththe idea of camber and have always been more inclined to try hinged battens to achieve camber. A fefew years ago i spoke with a very knowledgeable gentleman from this site who said if he had to do it all again he might just sew up some flat sails and go sailing. I myself am not much on taking pictures or youtubing but i may try and show some of my process when i get around to making the sails. To you experienced sailmakers it is probably so easy.  Thanks. Wade

  • 25 Jul 2019 15:38
    Reply # 7796692 on 7795562
    Deleted user

    I've been curious about Shirlz's decision to go back.  She cites two things:  she hated the baggy look, and the cambered sail required more maintenance.  And she's got more experience and capability than I'll ever have.

    1) In matters of aesthetic taste, there can be no arguments.  If someone doesn't like the look of their home, it can really wear on them.  I like the look of cambered sails and actually dislike the flat look.  I've spent too many years around airplanes and jet engines to see anything but drag and inefficiency in flat foils.

    2) Others have found that a camber sail doesn't necessarily lead to higher maintenance if particular steps are taken in the design. 

    It really would be so little effort to put some camber in.  But horses for courses.

  • 25 Jul 2019 15:15
    Reply # 7796660 on 7796257
    David wrote:
    Robert wrote:

     Here is a question: has anyone done cambered sails and regretted the change on a cruising boat.  Thanks Wade


    Paul Fay, Ti Gitu, wrote about this in JRA magazine 58.

    Speedwell of Hong Kong went from flat to camber and then back to flat. Shirlz posted an entry about this called Back to the basic junk sail.

  • 25 Jul 2019 12:04
    Reply # 7796466 on 7795562

    Hi, I have just been asked by Arni for an update on our cambered panel sails - which to start with Mo and I were not happy with. However now having sorted the problems we would not have anything else. I will write about all our findings over the next few days and post it here but I do need your patience as we are out sailing and will be drying Ti Gitu out to clean the bottom.

    I would ask David Tyler to re post his excellent formula for  calculating the batten angle with cambered panels which works perfectly.

  • 25 Jul 2019 10:34
    Reply # 7796336 on 7795562
    Anonymous member (Administrator)

    I think we should ask Paul Fay to write an update about his sails. That report was from 2011-12. I can see two reasons for his problems. The battens were on the light side at only, or even at less than 50mm on a 15-ton ship, the same as I used on my 3-ton Johanna. The batten parrels were quite long on the shown photo, which gives problems with negative batten stagger when reefing and furling the sail.

    As far as I know, Paul has sorted out these problems now, so it would be most interesting to hear his present view on the matter of cambered versus flat sails.

    Arne


  • 25 Jul 2019 09:13
    Reply # 7796257 on 7795562
    Robert wrote:

     Here is a question: has anyone done cambered sails and regretted the change on a cruising boat.  Thanks Wade


    Paul Fay, Ti Gitu, wrote about this in JRA magazine 58.
  • 25 Jul 2019 09:04
    Reply # 7796256 on 7795562

    Whether you build any shape into the panels, or whether you don't, I think we've all come to the conclusion that the PJR way of doing things, with long vertical cloths going right down the sail, is a hard way to proceed, and it's much easier to make a sail panel by panel. Join two panels, add the batten pocket, join another panel, and so on. You'll find some photos of my preferred method in this photo album. You can make a flat sail this way, or a cambered sail, just as easily. I would like to suggest that even if you're quite happy with a flat sail, you'll get it to set better if each panel has just a little rounding on its upper and lower edges. Here's the shaping for the lower panels of this sail - not extreme, not hard to do, and will make sure that even if you don't hinge the battens and get the full amount of camber that I was aiming for, the luff and leech will stay taut.

       " ...there is nothing - absolutely nothing - half so much worth doing as simply messing about in junk-rigged boats" 
                                                               - the Chinese Water Rat

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