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Sailmaking detail questions

  • 11 Mar 2013 00:36
    Quote
    Reply # 1239173 on 1239121
    Anonymous member
    Barry & Meps / Stellrecht & Schulte wrote:I'll jump in here with the people who helped me when I sewed my sails, and say a few things.

    First, the batten pockets are a lot less effort than the other choices. I'm happy with them.

    Second, if I had to do it over again, I would probably do what David Tyler did for chafe protection--sew a strip of 3/8" foam camping pad into the pocket, to stop it from banging, and sew something tough like seat-belt webbing over top to take the wear. (I've got chafe protection on my battens, but it was a lot of work and it squeaks)

    Mine aren't doing too well on this sail. Mostly because I used Arne's batten pocket method, and it's harder to keep the fender where it's supposed to be. It works better on the type of batten pocket that I've suggested to Daniel. Also, although I used car seat belt webbing which is hard and shiny, the fenders are getting scuffed more than I'm used to with previous sails. 

    Daniel, I suggest you leave a window in the batten pockets in way of the mast, and talk to John Cornicelli, who is not a million miles away from you, about the firehose he has plenty of. That could well be the best option for tubular batten fendering. Get some closed cell foam inside it if you can, to deaden the noise.
  • 11 Mar 2013 00:26
    Quote
    Reply # 1239162 on 1239104
    Anonymous member
    Daniel Collins wrote:
    David Tyler wrote:
    I find that's it's better on a cruising boat if the lengths of the leeches of the top panels are kept short. They are under better control when the sail is stowed, and when it's blowing hard. When I made Badger's tan sails, I added an extra unsheeted batten, to keep the top panels small, and you might also consider this. I have never found it necessary to hollow the leeches, provided that the edges of the panels are a little convex.

    In addition to the questions I just posted... this comes to the "proper angle for the yard" discussion, which is slightly off-topic here but since it has to do with the sail a bit, I'll hope you let it slide.  Right now I have 60 degrees for the yard angle on my sail, mostly from Kurt's article.   If I add a second batten there (Kurt's current top batten is, IIRC, 22 degrees as recommended in his article) would I need to increase the yard angle --- and are there other reasons why in a Badger-like sail I'd want to do that anyway?

    Just wondering aloud as before I finalize the sailplan I'd like to know what changes affect what and adding this batten will be an interesting tweak to the layout.
    There's a trade-off here. Steeper yard = more fan camber effect, but higher loadings on the hauling parrels and less relaxed sailing. Lower yard angle = less fan camber effect, but less load and more relaxed sailing. Take your pick. I'd recommend you stay with 60 degrees, which is what Blondie and Jock settled on after trying 70 degrees for a few rigs . It's a good angle for a schooner's sails. I've gone as high as 80 degrees, which is efficient but hard work. I wouldn't want a sail with less than 60 degrees yard angle except specifically for a split junk sail, with its very great balance area.

    Then just sub-divide the leech above the top sheeted batten into equal parts. There's no problem over batten stagger here, since the panels are triangular, so there's no need to consider panel diagonals, as you must for the lower parallelogram panels. 
  • 11 Mar 2013 00:12
    Quote
    Reply # 1239159 on 1239088
    Anonymous member
    Daniel Collins wrote:You guys are fantastic!  Excellent advice here...
    We aim to please!
    So, with pockets, how do you handle the parrels?  Do you use grommets to run the parrel around the batten and the sail together or do you make a gap in the pocket and run the parrel around the batten?  How do you affix the parrel to keep it from moving fore and aft along the batten?
    Make a window in the pocket. The usual thing is to make some kind of protrusion on the batten to stop the parrel sliding forward. I haven't found a screw head to be enough, and have used a 1" hole saw to make some discs out of 10mm HDPE sheet and then screwed them on with #10 self-tappers. My pockets are rather too tight, and I have to unscrew these discs to remove the batten - not ideal.
  • 10 Mar 2013 23:15
    Quote
    Reply # 1239121 on 1238226
    Deleted user
    I'll jump in here with the people who helped me when I sewed my sails, and say a few things.

    First, the batten pockets are a lot less effort than the other choices. I'm happy with them.

    Second, if I had to do it over again, I would probably do what David Tyler did for chafe protection--sew a strip of 3/8" foam camping pad into the pocket, to stop it from banging, and sew something tough like seat-belt webbing over top to take the wear. (I've got chafe protection on my battens, but it was a lot of work and it squeaks)

    Third, you sound like you are still thinking about what angle to make the head of your sail. On a purely practical non-aerodynamic point, I did discover that how the sail likes to hang impacts that--Sails with more balance want flatter angle yards (Van Loan or Slieve's split sail), and sails with less balance want steeper angle yards. (Hasler-McLeod, Fantail, or Arne's) If you get this right, your sail will need less effort with the various parrels to get it oriented where you drew it.
  • 10 Mar 2013 22:43
    Quote
    Reply # 1239104 on 1238995
    Deleted user
    David Tyler wrote:
    I find that's it's better on a cruising boat if the lengths of the leeches of the top panels are kept short. They are under better control when the sail is stowed, and when it's blowing hard. When I made Badger's tan sails, I added an extra unsheeted batten, to keep the top panels small, and you might also consider this. I have never found it necessary to hollow the leeches, provided that the edges of the panels are a little convex.

    In addition to the questions I just posted... this comes to the "proper angle for the yard" discussion, which is slightly off-topic here but since it has to do with the sail a bit, I'll hope you let it slide.  Right now I have 60 degrees for the yard angle on my sail, mostly from Kurt's article.   If I add a second batten there (Kurt's current top batten is, IIRC, 22 degrees as recommended in his article) would I need to increase the yard angle --- and are there other reasons why in a Badger-like sail I'd want to do that anyway?

    Just wondering aloud as before I finalize the sailplan I'd like to know what changes affect what and adding this batten will be an interesting tweak to the layout.
  • 10 Mar 2013 22:10
    Quote
    Reply # 1239088 on 1238226
    Deleted user
    You guys are fantastic!  Excellent advice here...

    Ok, I'll do pockets, and I'll do vertically-seamed slightly rounded panels - the main reason being that I'm working in a living room as well and cannot lay the entire parallelogram out at once ... as nice as it would be.  In that case it makes sense to do the pocket assembly method you recommend, David, combined with Kurt's batten arrangement.  I'm seriously considering that second top batten, as it not only looks great but if it helps when deeply reefed in a blow, I'll take the help.

    So, with pockets, how do you handle the parrels?  Do you use grommets to run the parrel around the batten and the sail together or do you make a gap in the pocket and run the parrel around the batten?  How do you affix the parrel to keep it from moving fore and aft along the batten?
  • 10 Mar 2013 18:28
    Quote
    Reply # 1238995 on 1238226
    Anonymous member
    I've made a sketch of a batten pocket arrangement that I think will suit you. If you sew the two panels together with just a single line of zigzag stitches, then assemble the pocket/patch and the reverse side patch with double sided tape. then stitch at top and bottom with a single line of zigzag stitches, you are, in effect, making a triple stitched seam between the panels, and the actual seam is totally protected.

    A distinct advantage of making a sail panel-by-panel is that it can be done in a smaller space. A year ago, David Thatcher and I made our new, very large sails in his living room.

    Another tip for a long-lasted sail is to add a doubler in way of the mast, with a width of about two mast diameters, at least for the bottom two panels. When you make a long passage with one or two reefs down, there is a likelihood that the sail will be trapped between the batten and the mast, and the batten moving slightly back and fore as the boat pitches will tend to chafe small holes in these panels.

    I find that's it's better on a cruising boat if the lengths of the leeches of the top panels are kept short. They are under better control when the sail is stowed, and when it's blowing hard. When I made Badger's tan sails, I added an extra unsheeted batten, to keep the top panels small, and you might also consider this. I have never found it necessary to hollow the leeches, provided that the edges of the panels are a little convex.
  • 10 Mar 2013 18:27
    Quote
    Reply # 1238994 on 1238226
    Anonymous member
    Hi Daniel,

    Pockets - If I'd spent the time it took to hammer in a couple hundred grommets thinking instead about how to make batten pockets work as well, and then spent the time it took to lash battens through grommets implementing the ideas, we'd have really good pockets. As it is, we have very-high-quality cable ties...

    There are other people who can help you with pocket details. 

    Construction - I looked out on the brand-new flat vertically-seamed acre of fabric, big enough for the parellelogram portion of our sail, on the firehall floor. Let's see... we could cut it up into individual panels and sew them back together with horizontal seams and batten strips, or... we could roll it up and master getting it through the sewing machine. 

    For a flat sail and easy-working fabric like Top Gun or Odyssey, the latter was a clear choice. Even if someone could now point and show me the bad effect of not rounding .5% between panels, I wouldn't cut the sail apart to put it in. This is soft fabric, not thin plywood!

    (Cambered panels, they say, deserve such cutting and sewing, cutting and sewing...) 

    After that, and the one awkward seam to the top section, it was all perimeter work. (I've only made 2 junk sails and a few Bermudian ones, on a beefed-up household sewing machine. Others have made heaps more.) 

    Upper panels - aerodynamic advantage question... - No. 

    In mehitabel's flat sail article, there's a profile sail-plan photo, and the text also describes what departures I made from Hasler & McLeod's plan. And what I'd do next time. (I have a mehitabel sail-plan equivalent to PJR Fig.6.34, in terms of B & P & U and so on, if you're interested.)

    I do like the result of my not-so-original changes. I would use slightly higher 'fan' angles, as the article says, if I were making your sails, which I'm not. Creative fine-tuning and invention are your fun.

    Our top batten is sometimes sheeted; I keep the sheet-end in the deck block with a stopper knot, ready to be hitched to the top batten, but we sail without sheeting it most of the time.

    In a supersonic aircraft association, we'd have to be more careful what we say.

    Cheers,
    Kurt

    Last modified: 10 Mar 2013 18:45 | Anonymous member
  • 10 Mar 2013 15:02
    Quote
    Reply # 1238906 on 1238226
    Deleted user
    Great additional info...

    So if I gather correctly, pockets are not as bad of a thing as they have been made out to be in the past, and horizontal seams, when well done and properly protected, are pretty bombproof.  Cool.  

    It sounds from the two of you that the best idea is to make individual "panels" out of the three widths of O3 cloth, overlap at the batten position with a smidge of round (say 3/4" or so), slap on a backside patch and a frontside pocket/patch combo, and move on to the next panel?

    I have been so focused on grommets I haven't thought about how to sew a pocket on.  Is it just a loop of cloth hanging down with hemmed ends, or is there more of a trick to it?

    Also, is there an aerodynamic benefit to having the leech end of the topmost (unsheeted) batten at exactly the middle between the yard and the second panel or is that just an aesthetic preference?  I understand from your article, Kurt, that yours is at a slightly lower ~22 degree angle instead of splitting the distance on the leech?

    Thanks so much everybody, I'm learning a LOT here.
  • 10 Mar 2013 05:25
    Quote
    Reply # 1238778 on 1238226
    Anonymous member
    Hi Daniel,

    I'll venture the following about details, assuming flat-cut sails:

    - A perimeter bolt-rope is a Very Strong Thing that is not needed. Wide tabling as David describes is wider than we have, and that's adequate. I put webbing inside the tabling in the top panel as storm reinforcement.

    - Good practice doesn't change thickness by more than 1 ply anywhere, so batten backing strip and patch edges should be stepped, staggered, offset from each other. (David's tabling does this automatically.)

    - At each batten-end, a triangular patch seems right to me. That is, it'd look weak and wrong without it. With wide tabling overlapping from above and below, maybe not necessary but still proper-looking.

    - We chose grommets and lashings and backing battens, for theoretical serviceability. With a little forethought, like placement of gaps, pockets are serviceable, cheaper and simpler. Backing battens are bulky and don't really pay their way. Next time.

    - Vertical seams for the main part of the sail aren't so much of a compromise that you'd ever notice the difference. And we got ours through the sewing machine somehow.

    - A soft fabric like Odyssey will be very forgiving even if you choose to omit the fine-tuning steps, such as the edge-rounding that David suggests. Very correct, but not a thing I'd notice if the boat were moving. Leech hollow in the upper panels, I would sometimes notice, if I'd left out that step.

    - Our heavier Top Gun fabric stretched more than I predicted. It's easier to shorten battens later, than lengthen them. (In the process, please invent the perfect way to avoid batten-ends snagging anything, and share it.)

    I think you'll be happy with your flat sails. They're wonderful things.

    Cheers,
    Kurt
       " ...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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