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#1
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MiniCup Sail
My old visqueen sails for the MiniCups finally fell apart so I have
bought some white polytarp material to make new ones. The old directions said nothing about shaping the sails but the polytarp sail manual discusses it. However, they also make reference to lateen sails being self shaping. So, what to do, cut them with a curvature (what I plan to do) or make straight cuts? Next, how much does stitching lengthen the life of the sails? |
#2
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) writes: However, they also make reference to lateen sails being self shaping. Wind tunnel test have shown lateen sails to be the least efficient. The lower the angle of the top spar the less efficient the sail. -- ------------------------------------------------------------------------------ William R Watt National Capital FreeNet Ottawa's free community network homepage: www.ncf.ca/~ag384/top.htm warning: non-FreeNet email must have "notspam" in subject or it's returned |
#3
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#4
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Interesting theory. When I was racing my Sunfish, I was able to go to
windward much better after the sail developed some body. The drill with a new sail was to run it thru the washing machine some six or eight times to soften it. Some years later the official Sunfish lateen was given more body in the sail loft. Roger http://home.earthlink.net/~derbyrm "Paul Oman" wrote in message ... wrote: My old visqueen sails for the MiniCups finally fell apart so I have bought some white polytarp material to make new ones. The old directions said nothing about shaping the sails but the polytarp sail manual discusses it. However, they also make reference to lateen sails being self shaping. So, what to do, cut them with a curvature (what I plan to do) or make straight cuts? Next, how much does stitching lengthen the life of the sails? Yes - lateen sails are flat - no 'body' sewn into them paul oman progressive epoxy polymers |
#6
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#7
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DSK ) writes: Next, how much does stitching lengthen the life of the sails? Not at all, but it could shorten it. shouldn't someone warn the professional sail lofts about this? the only problem with both taping and sewing seams is the glue gums up the needle on the sewing machine. I cello-taped the seams of a nylon sail to hold them togeher while I shoved them through a sewing machine and had quite a problem with cleaning the needle. Last year I sewed a Tyvek sail without using any tape and it looks good. I haven't tried a heat sealed polytarp sail. Photos of the nylon sail under "Dogskiff" and Tyvek sail under "Tyvek Sail", both under "Boats" on my website (see below). -- ------------------------------------------------------------------------------ William R Watt National Capital FreeNet Ottawa's free community network homepage: www.ncf.ca/~ag384/top.htm warning: non-FreeNet email must have "notspam" in subject or it's returned |
#8
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Next, how much does stitching lengthen the life of the sails?
Not at all, but it could shorten it. William R. Watt wrote: shouldn't someone warn the professional sail lofts about this? I think most of the good ones already know. the only problem with both taping and sewing seams is the glue gums up the needle on the sewing machine. Why sew them if they're glued? Many sail lofts are now producing glued seam sails... I have a ~200 Sq Ft spinnaker that I've flown in 20+ knot winds, plenty strong. Fresh Breezes- Doug King |
#9
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Being a pathological experimenter (There ought to be a 12 step program
for people who cannot follow directions), the polytarp allows me to economically stay in touch with my inner geekiness. |
#10
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On Sun, 17 Apr 2005 23:35:33 -0400, DSK wrote:
wrote: My old visqueen sails for the MiniCups finally fell apart After how many hours of use? In what average strength wind? ... so I have bought some white polytarp material to make new ones. The old directions said nothing about shaping the sails but the polytarp sail manual discusses it. By broadseaming of luff curvature? You might try putting a little shape in one seam and a few inches of luff curvature... the right curve will make a noticable difference in how the boat sails. ... However, they also make reference to lateen sails being self shaping. So, what to do, cut them with a curvature (what I plan to do) or make straight cuts? If a lateen rig has any "self-shaping" properties then it would be the opposite shape of what is desired. The leach tension would tend to bend the gaff or lateen upper spar so as to pull cloth out of the middle of the sail... if the sail were cut flat, then this inverted shape would be horrible. If the sail were cut with the proper shaping for light/moderate wind (ie with no bend in the gaff) then the "self-shaping" could become beneficial; ie flattening the sail & depowering it when that would be desirable. Next, how much does stitching lengthen the life of the sails? Not at all, but it could shorten it. Rodney Myrvaagnes wrote: If you are really interested in extending the life of your sails, why not try sailcloth? Oh man, you just don't understand creative thinking & original problem solving! It is much better to have to make new sails every couple of months, that way you can recycle the material faster and spend far less money in the short run, plus spend a lot of time (which of course only equates to money if you are a capitalist brain-dead bourgeoisie) communing with the inner spirit of your wind-capturing device... DSK OK, I understand. Suggestion withdrawn. :-) Rodney Myrvaagnes Opionated old geezer Faith-based economics: It's deja voodoo all over again |
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