Good sailcloth for JR

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  • 26 May 2018 11:21
    Reply # 6263891 on 1206989
    Anonymous member (Administrator)

    Again, I think there is a mismatch between the needle size and thread size. Reducing the needle size will no doubt reduce the pressure needed to push it through the cloth. Even if you end up breaking a few needles, that would be a minor price to pay to get a pucker-free seam.

    I once destroyed a whole sail due to (lots of) pucker and lack of experience to understand what was happening (1992, see NL26, p.12). I didn't even know the word 'pucker' at the time...

    Arne

  • 26 May 2018 10:40
    Reply # 6263871 on 1206989

    Thank you for the comments, it helped in the thinking process. I wasn't there in person when she did it, but the resume was something like: "as the fabric has that thick texture it deforms more while the needle goes through it, especially doing the triple zig-zag. Changing the shape of the zig-zag to a bit more gentle and keeping the seam a bit under tension while sewing seemed to do the job.
    Not perfect, though, but overall it looks satisfying enough to move on.

  • 25 May 2018 16:05
    Reply # 6261311 on 6259930
    Hard Perk wrote:

    The needle was 120 and the thread 45. They use similar materials often, also repairing sails. The machine is a professional one in good shape. We'll try out some different approaches tomorrow. 


    http://www.amannusa.com/pdf/nahtkraeuslen_gb.pdf

    This guide to puckering might be of use.


  • 25 May 2018 15:35
    Reply # 6261280 on 1206989

    When i had problems with the needle gumming up i ran the thread through a swab of alcohol before it went through the tension mechanism (film canister with a cotton ball).  The issue went away with waxed thread.

    I like WeatherMax - it has a nice hand, seems to be elastic and not take on a permanent set, gets along well with my hotknife, and i was able to get half if my 500 sq foot sail through the throat of my sewing machine.  But Topgun 9 sewed more easily and did not pucker.  That material does not come in the color we want.

  • 25 May 2018 10:09
    Reply # 6260915 on 1206989
    Anonymous member (Administrator)

    Hard.

    For the last three junksails I have made, all from 220g/sqm (6.5oz) Odyssey III, I have used the thick T-90 (V-92?) thread. My thinking behind it was that I wanted to use the thickest thread that my machine could sew fairly well. All the professionally made sails, sprayhoods and awnings I have seen, have failed in the seams before the cloth gave up. As late as yesterday, I hand-stitched a broken seam on a batten pocket on Samson’s (professionally made) 70sqm mainsail.

    Even when using that thick T-90 ‘haywire’ thread, I only need 110 needle.

    I suggest trying a thinner needle as well as reducing thread tension. You may get away with as thin as size 90 (=0.90mm). If you can get your hands on some thicker thread, say V-68(?), I think that will pay you back in the long run.

    Arne

    PS: Just a thought  -  could it be that the basting tape increases the resistance and augments any tendency to puckering? I have only used tape a couple of times, and found that it stuck badly on the needle.


  • 25 May 2018 08:07
    Reply # 6260848 on 6259731
    The last time I had similar problems, I put more pressure on the foot, and that did the job.  I'm not quite sure why - this sort of puckering usually happens with very light fabrics, but I suspect it could be from trying to send long lengths of material through the machine.
  • 25 May 2018 02:19
    Reply # 6260468 on 1206989

    120 is a large needle and 45 is thin thread.  I used 100 and 110 needles with 69 thread.  I did have to change to bobbin more often.   You can use this as a guide http://www.tolindsewmach.com/thread-chart.html and play with the needle size. What kind of machine are you sewing with.  Other ideas...

    • Paul's thoughts on the size of the hole in the needle plate and adjusting the tread tension super low are right on.  You are doing zig zag, so you have a slot in your plate, but the same applies.  You may be able to use silver solder to narrow the slot if necessary.
    • Use a large foot on your machine.  I tried a roller foot without luck.
    • Check timing of the needle vs the feed dogs.  Check feed dog height.  Make sure your machine is to specs.  
    • Consider rolling the seams with a pipe or tube after taping to better help hold the layers together.  
    • When taping, stretch the lower and upper cloth equally such that the tension matches - in your pictures you are already developing some wrinkles when the cloth is just tapped.  If you are using pins to hold the lower cloth down, pre-stretch it and then carefully apply the upper seam layer.  Release the pins and see what you got.  Repeat... 
    • Large stitch length helps - go to the max your machine can do.
    • 10 mm wide remnants, about 500mm long are sufficient to practice on and tune your machine.
    • The cloth is hard to sew!  I struggled.  My sail maker struggled with his project.  Very slight cloth pucker will come out under tension from the wind.  You got quite a bit though and I definitely understand your concern.
    • You have a triple stitch zig-zag.  Can you get away with a single row rather than two.  That would decrease your puckering. 
    • WeatherMax is very elastic cloth - try not to sew it on the bias https://www.canvas-boat-cover-and-repair-advisor.com/how-do-you-stop-the-puckering-on-weathermax-seams-comments.html
    • Guide by the manufacturer: https://issuu.com/challengesailcloth/docs/challenge_sailcloth_weathermax_prod

    Let us know how things turn out.

    Last modified: 25 May 2018 13:44 | Anonymous member (Administrator)
  • 25 May 2018 01:35
    Reply # 6260389 on 1206989

    Speaking of Weathermax, I think that is probably what I will use, but I was wondering if something a little lighter than weathermax 80 would be OK. They have here a product called weathermax lite. 

    Weathermax 80 is 8 oz. and weathermax lite is 6.5 oz

    I will be getting around to buying the cloth soon.

    For coastal cruising in a  3 ton boat, would the 6.5 oz be OK?

  • 25 May 2018 01:11
    Reply # 6260378 on 6259930
    Hard Perk wrote:
    Arne Kverneland wrote:

    Hard,

    how thick thread  and needle are you using?

    Are you able to reduce the thread tension, both on the under-thread and over-thread?

    It looks to me tha slacker thread tension is needed.

    Arne

    The needle was 120 and the thread 45. They use similar materials often, also repairing sails. The machine is a professional one in good shape. We'll try out some different approaches tomorrow. 


    Possibly  to much tension. The other thing to look at is the size of the opening that the needle goes through on the needle plate. If you are using a professional sailmaking machine then that hole is probably rather large. Not a problem with stiff sail cloth but Weathermax is soft and dimples with every stitch...

    A smaller needle and or closing up the opening a bit should help. Plus the minimum amount of tension that will work. The seams are the most difficult, once you have three or more layers, things go better.



  • 24 May 2018 20:46
    Reply # 6259930 on 6259865
    Arne Kverneland wrote:

    Hard,

    how thick thread  and needle are you using?

    Are you able to reduce the thread tension, both on the under-thread and over-thread?

    It looks to me tha slacker thread tension is needed.

    Arne

    The needle was 120 and the thread 45. They use similar materials often, also repairing sails. The machine is a professional one in good shape. We'll try out some different approaches tomorrow. 


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