Good sailcloth for JR

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  • 22 Sep 2018 12:22
    Reply # 6687311 on 1206989

    This subject got me thinking about how, hypothetically, I'd set about making SibLim's sail.

    It doesn’t seem to be a very good plan to think of shelves, as that seam would be along the warp. Vertical cloths in the panels are also out for the same reason, so broadseam is out. I come back to tucks as being the way to do it, with the least sewing within the panels and that sewing being along the weft, and with seams along the battens only, where the puckering can be pulled out easily, or simply ignored. I’ve had a quick look at the drawing again, and there doesn’t appear to be much adjustment needed to make this feasible. The lower three panels will come out of single cloths as they are, and the upper three panels just need slight adjustments to their leech lengths. In the accompanying image of the shape of the lower three panels, the cloth is magenta, the panel cut from it is black.

  • 21 Sep 2018 01:29
    Reply # 6685408 on 1206989

    Thought I'd post a photo of pucker in a sail currently under construction. The top  most panel in the foresail for Roger Fullerton's Feng Zheng.

    BTW: This particular seam was sewn on the Sailrite LZ1. The Elize gets rather less pucker but I did not yet have it when I did this panel.

    Last modified: 21 Sep 2018 01:32 | Anonymous member
  • 20 Sep 2018 22:15
    Reply # 6685211 on 6677220
    Anonymous wrote:

    just for the sake of science:

    In case you have a bit leftover from that Weathermax cloth, what about measuring up a strip of exactly 1m x 50mm? If you then wrap this (lengthwise) and run a seam along it, how long is the test strip after sewing?

    Arne

    Arne, here are my samples.
     
    Both 1M x 50mm bent over once. Left example is along the roll and it's where the pucker occurs. After sewing the piece was 92mm long giving me 8% shrinkage. It was easily stretched to 1M but always pulled back to 92mm.
     
    Right example was across the roll and after sewing was 99mm giving 1% shrinkage. The pucker is minimal once you are sewing more than two layers.
     
     Machine: Elize LZ9-245-5NL top & bottom feed walking foot machine.
     Needle: DPx35 SERV7 size:21
     Thread: Anefil poly V69


    Update, I thought I'd check out the the along role pucker but this time with basting tape. It does help reduce pucker... found it to be reduced to 4% on my machine.


    Last modified: 21 Sep 2018 01:16 | Anonymous member
  • 20 Sep 2018 20:22
    Reply # 6684980 on 6677977
    Anonymous wrote:

    Paul,

    That's strange, I have no puckering across the roll, on the short ends of my sail cover, only along the roll. So, if a panel were cut from one horizontal cloth, the tabling at luff and leech would not be puckered, but the seam between panels, in way of the batten, where it hardly matters, would be puckered.

    Machine: Bigfoot RZZ9
    Thread: Hemingway and Bartlett Dabond V69
    Needle: Schmetz 135x5 size 19


    Hi David, we are saying the same thing, just  a mix up with terminology. Across the roll, no pucker, along the roll, pucker. Your photo cleared it up for me.

    Indeed, when it's along the batten it's not a big issue, however it is rather more of an issue when two sections have to be joined....


    Last modified: 20 Sep 2018 20:26 | Anonymous member
  • 20 Sep 2018 09:25
    Reply # 6677977 on 1206989

    Arne,

    Your test carried out on a 835mm x 50mm strip, folded over and sewn once with zigzag stitch: finished length 823mm, 98.5% of the original length.

    Your test carried out on a 835mm x 50mm strip, folded over and sewn once with straight stitch: finished length 817mm, 98% of the original length.

    Paul,

    That's strange, I have no puckering across the roll, on the short ends of my sail cover, only along the roll. So, if a panel were cut from one horizontal cloth, the tabling at luff and leech would not be puckered, but the seam between panels, in way of the batten, where it hardly matters, would be puckered.

    Machine: Bigfoot RZZ9
    Thread: Hemingway and Bartlett Dabond V69
    Needle: Schmetz 135x5 size 19


  • 20 Sep 2018 07:25
    Reply # 6677776 on 6263871
    Anonymous wrote:

    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.

    Yes, that is about as good as it gets.
  • 20 Sep 2018 02:24
    Reply # 6677529 on 1206989

    Weathermax has a pronounced weave in that it's very orientated and pronounced in one direction and all but disappears in the other direction. My new machine (an Elize professional sailmaking machine) can sew along the weave without puckering but across the weave, nothing helps. You can by using the various techniques that David has mentioned minimise the pucker but you cannot eliminate it. Once you are sewing more than two layers, the problem disappears. My Sailrite LZ1 machine on the other hand, produces pucker no matter which way I sew.

    Another peculiarity of the material is that is is highly resistant to penetration by the needle and once the layers start piling up it becomes hard work for the machine. It also means that a heavier than normal needle has to be used, else you get a lot of breakage.

    It's not a material that I'd recommend to a beginner or the inexperienced and doubly so if you only have a domestic machine. Topgun 9 is much easier to work with and it's what I now recommend. None the less I've still a few more sails to make in Weathermax including my own as I've already got the material.

    Last modified: 20 Sep 2018 07:12 | Anonymous member
  • 19 Sep 2018 21:24
    Reply # 6677220 on 1206989
    Anonymous member (Administrator)

    David,

    just for the sake of science:

    In case you have a bit leftover from that Weathermax cloth, what about measuring up a strip of exactly 1m x 50mm? If you then wrap this (lengthwise) and run a seam along it, how long is the test strip after sewing?

    Arne

    Last modified: 19 Sep 2018 21:25 | Anonymous member (Administrator)
  • 19 Sep 2018 20:54
    Reply # 6677168 on 1206989
    Paul wrote:
    David wrote:

     I think that I'd choose Weathermax 80 for a mid weight cloth, where Top Gun was too heavy.

    Have you sewn with Weathermax yet? If not, I'd hold my horses in recommending it to inexperienced/budding sailmakers. It is not easy material to work with.

    ----------------------

    Agreed, Paul. I should only preach what I practice. So, I bought some Weathermax for the sailcover that I should have made last winter.

    I followed the recommendations: stretch the cloth as the basting tape is applied; slack thread, both top and bottom; keep the cloth under tension as it passes under the needle. I still got puckering on a rolled tabling, 40mm wide, but a sailmaker's lapped seam, 20mm wide with two lines of zigzag stitching was acceptable. The puckering varied in amount, but was always there, whatever I did. The strange thing is that when the finished tabling is tensioned, the puckering can be pulled out flat. I guess, therefore, that it's not the stitching that's holding the puckering, as is sometimes the case with a thin soft material, but a feature of the Weathermax material itself.

    Then I tried the same rolled tabling on a scrap of the Clipper Canvas that my current sail is made from, on the same machine settings - no problem, very little distortion, although the cloth is quite soft, as is Weathermax.

    I tried a needle meant for leather, with an edge rather than a conical point - no improvement. 

    I conclude, as others have done, that though Weathermax feels very good, and has the kind of properties in service that we need for a junk sail, some puckering has to be expected, even in the hands of an experienced machinist. There is possibly one way in which this can be turned into an advantage: in sewing the seam between two of Arne's flat, barrel-cut panels, we would like to reduce the length of the seam by sewing tightly, building in some gathering. Otherwise, the puckering is undesirable, cosmetically, even if it won't affect performance too much. It's a shame that you have to pay top dollar for Weathermax, and still can't achieve an absolutely perfect result in all respects.

  • 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

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