New sail for a Coromandel. What design and to self sew or not?

  • 01 Feb 2021 11:47
    Reply # 10052684 on 10048319
    Anonymous member (Administrator)

    Bonjour

     I suggest a low-cost quick and dirty temporary improvement that I experienced on Mingming.

    Most of Mingming sail (the two top panels have been replaced) must be as old as yours and have sailed many more miles. It is still at post ! I restitched all the seams because the thread was rotten out by the UV.

    The battens were made out with semi-flexible electric 1 inch PVC tubes, reinforced by soft wood for the higher ones. They were also rotten by the UV and breaking quite easily.
     
    For other purpose (experimentation), I changed the battens to very (on experimental purpose ) flexible glass polyester rods and changed the sheeting system for a double sheet (starboard and port) lambda sheeting system.

    I had issue with the front part of the battens and suffer nice S bending (as described in PJR) and I just doubled the 30% forward part of the battens. The doubled part is linked with the batten by gaff tape.

    The lambda sheeting consist in adding a parrel between the rear end of the batten and the 30% back point on each side of the sail for the sheeted battens. Then, on each side, the sheet is fixed to the middle of the parrel instead of the rear end of the sail.

    Doing so, the camber of the sail remains almost constant when the wind velocity increase.

    The shape of the sail is far from optimal with a rather flat forward part, a camber in the middle part and a flat after part.

    It only cost a few blocs and a second sheet.

    It is easy to sail but the main cons is that you have two sheet spaghetti nests instead of one. The aerial part of the non operating sheet is not an issue as it remains behind the sail.
    Eric


    2 files
    Last modified: 01 Feb 2021 11:51 | Anonymous member (Administrator)
  • 31 Jan 2021 23:26
    Reply # 10051549 on 10048319
    Anonymous member (Administrator)

    Link;

    Good, or bad, see for yourself: The Junk Rig Association - Arne Kverneland

    If you start up to the left, you'll find some chapters about designing and making a JR with cambered panels.
    Arne

  • 31 Jan 2021 18:30
    Reply # 10050895 on 10048319
    Deleted user

    Thank you so much David, Michael and Arne for your thoughts and expert knowledge.  It is now quite clear to me that I need to make my own cambered sail.  I will go though this site and try and find as much as I can before asking any questions. I assume this part of the forum is the right place for questions. I will try and keep them to a minimum.  I will get familiar with what I am to do over the next few months and sail with my old sack for the summer (my children are still of an age where throwing estuary mud at my sail is 'fun' anyway.....) and then look to start sail making towards the end of the year. 

    Thank you again. If there are any good links you would like to send my way I am sure they woulc be invaluable to me.

    John.

  • 31 Jan 2021 15:52
    Reply # 10050568 on 10048319
    Anonymous member (Administrator)

    John,
    the idea of sewing one’s own sail may sound scary, in particular if you have never ‘set foot in’ a sewing machine. However, after just a little practice, it is not harder to make half-straight seams than to make half-straight cuts with a jig-saw or band-saw.  If you can have someone give you a one-hour start-up course, you will be ready for a couple of exercises, for instance making a shopping bag or sail bag. The one-hour course will be about how to reeve the (upper) thread, how to spool the under-thread and install the spool, and then to adjust the thread tension to get the stitches right.

    The construction method I use for my sails almost completely avoids rolling up canvas under the arm of the machine: Just about all sewing is along an edge, so there is no need for  long tables on both sides of the sewing machine.

    I have found that there is no (legal) home-activity, which pays better than making my own sails.

    Arne


  • 30 Jan 2021 22:54
    Reply # 10049184 on 10048319

    Hi John,

    we bought our Coromandel Mai Poy with a sunbird-rig with double-cone-hinged battens and the old original rig. After one year we sold the original rig for small money and stood with the sunbird rig. If I will replace the sail somewhen in the future, I would choose a cambered sail in Arne´s style. I would not replace the old sail with an old styled new sail, even if the wooden boom and yard looks dignified. There was much progress in junk rig in the last thirty years.

    I would sew it by my own.

    Good Luck by coming to a decision

    Michael

    Last modified: 30 Jan 2021 22:55 | Anonymous member
  • 30 Jan 2021 19:34
    Reply # 10048784 on 10048319

    Hi John, 

    cambered sails are definitely worth the extra effort, especially in light air. The improvement in windward performance is marked over a flat sail.

    Building a cambered sail according to Arnie's instructions is not difficult and should make a worthwhile winter project. Building your own sail is a very rewarding project and you will get great satisfaction in the years to come whenever you sail with it.

    All the best with the project.

    David.

  • 30 Jan 2021 14:33
    Message # 10048319
    Deleted user

    Hi There,  In the few times I have posted in the JRA I have posted in the wrong place...  I think I have the right place for this, and if not I will get my coat....

    I have a Newbridge Coromandel.  It has the very delipidated original sail.  Someone over the years put bendy battons in the sail. I love to sail her but have never really left the harbour (Salcombe, UK) as I have been working on her and have other commitments.  

    She badly needs a new sail.  I don't have loads of time as have kids and work to keep me occupied.  I have found a local sail maker who reckons he can make a new (like for like) new sail for around £1000. Or I could make one my self.  My first question is; are the benefits of learning how to make a sail worth allocating lots of time to or should I just get one made so I can keep sailing.  Any thoughts would be amazing.

    My second question is one of design. I am hoping if I go a new sail (the same as I have now) I would see some improvements in performance simply because it would be new.  I would refit stiff battens.  Should I take the opportunity to go for a cambered sail or a split junk or just stick with the design that came with the boat and that I know? I guess I am asking if I would (in the long term) regret not 'upgrading' my rig some how.

    I am aware that there are not set answers for these questions so I am just looking to get a feel. I live remotely and have no one locally I can to talk to about this so wanted to put my questions on here.  

    I enjoy working on boats but much prefer sailing them and with limited time I want to spend most of my available time sailing.

    I look forward to any thoughts any one may have.

    Thank's in advance and have a good day.

    John (Coromandel 'China Girl, Salcombe, Devon, UK).




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