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#1
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I just bought the material to make the sail for our still unfinished
10' nesting sailboat. I took another look at the material (thin nylon) at Walmart and did find that you could readily blow air through it and quickly decided against it. Then I found material that looks suspiciously like real dacron sailcloth. The clerks had no idea what it was. It's strong (I can't tear a thin sample of the cloth), it melts with a match...and it's much thicker than the nylon material AND you can't blow through it at all. At $1/yd, I couldn't resist it. At that price, I figured it's worth playing with (even if it is bright, BRIGHT yellow). Now I'm trying to figure out how to design the sail. Hubby finally decided that he didn't want the sprit sail and opted for a cat rig instead. This material is 56" wide and I'm wondering if I should just sew the panels together (using the full width of the material) or what??? It looks like most sails use narrower panels but it seems silly to cut the material only to resew it. Also not sure how to go about shaping the sails. I'm thinking of keeping it simple and just sewing the panels flat and shaping the sail somewhat by curving the edges of the sail. Appreciate any suggestions. Not looking for a professional sail...just trying to do the best I can without knowing what I'm doing. Thanks! Sandy |
#2
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Sandy, you need to get hold of a copy of The Sail Makers Apprentice, by
Emiliano Marino.. This book will take some of the mystery out of the sail making task.. There is no doubt that you can make your sail without this book but if you want this to be a good learning experience, with a sail that will look and perform good and you can be proud of, then find a copy.. One of the most important factors in selecting a material for a sail that will hold it's shape, is whether it will stretch when you set it and when you get some wind pressure on it.. The Nylon would have been a mistake and I hope this other material will resist the tendency to stretch. There are two methods to getting shape in a sail. The most common with todays low stretch sail cloth is accomplished by "broad seaming". This is a method of controling the amount of sail cloth in each sail panel by varing either the width of the panel or sewing a wider seam in the areas where you want to reduce the area.. In the old days (when I sewed my first canvas sail), the sail was sewn up flat with uniform panel and seam widths, and then you cut a curve in the luff and foot. That was fine for canvas because the material could "set" to the shape under pressure. Modern sail fabrics can cope with this slight bias stretching and with wrinkle. If you were to order a sail kit from Sail Rite, they would computer cut each sail cloth panel to the width required, the computer would put match marks on each panel so you would be sewing everything exactly as the computer calculated. But then "What would you have learned"? How to measure for your sail and how to operate your sewing machine (which I suspect you already know). Ask around for a copy of the book in your area or ask you public library to get a copy.. (they often have budgets for special book orders and never know what to the public needs) If you in the Puget Sound area, I could loan you my copy.. Steve s/v Good Intentions |
#3
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![]() "Steve" wrote in message the shape under pressure. Modern sail fabrics can cope with this slight bias stretching and with wrinkle. Correction: This line should read " Modern sail fabrics CAN'T cope with this slight bias stretching and with wrinkle. " Steve s/v Good Intentions |
#4
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On Sat, 14 Feb 2004 16:47:37 -0800, "Steve" vaguely
proposed a theory .......and in reply I say!: Correction: This line should read " Modern sail fabrics CAN'T cope with this slight bias stretching and with wrinkle. " will wrinkle.... G Sorry. reminds me of a story about a news articel about an old soldier who had died. He was described a a "battle scared veteran" in the paper. When asked to reprint, it came out "Bottle scarred veteran" G ************************************************** ** sorry ..........no I'm not! remove ns from my header address to reply via email Spike....Spike? Hello? |
#6
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![]() sail size: look at boats of similar size, shape, and displacement. there are two guidelines and one caution. first, in light winds you need 2 to 2.25 times the wetted surface of the hull. second, in stronger winds you need 1 to 1.3 times the square root of the sail area divided by the cube root of the displacement. make it closer to 1.3 for small boats. the caution is not to put so much sail on that a nice breeze will blow the boat over. there's no good way of calculating that. you have to look at other boats. some people put reef points in their sails to make them smaller when the wind blows stronger but small dingys usually don't have them because nobody's supposed to sail boats that small in strong winds. OTOH I've seen lots of racing dingys get blown over in strong winds. the sail on my 11 ft one person skiff is 42 sq ft. I put reef points in it but never use them. shape: the aspect ratio of a triangular sail is the square of the height divided by the sail area and should be about 4. I don't think you will have to cut your 5 ft bolt into panels. you can put a curve in the edges. use the calculations for the sprit sail on my website. they are good for trianglular sails too. reinforcing: add triangles up to 1 ft of cloth at all 3 corners to make the sail double thick there. you can sew rope along the forward and bottom edges of the sail. mast attachment: I like a mast sleeve (like on a Laser) but you can sew loops of sail cloth or light line to the front of the sail instead, one every 12" or so. the air escaping around the mast on these sails reduces power a bit. you don't see loops on boat used for racing. for pleasure sailing it doesn't matter. boom: not needed on a really small boat. if the bottom of the sail is more than 5 ft consider a loose footed boom where the sail is only attached at the front and back ends of the boom. the boom will hold the sail out better when the sail is out ot the side. that's the basics. you sould be able to find info in books at the public library. -- ------------------------------------------------------------------------------ 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 |
#7
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William R. Watt ) writes:
shape: ..... I don't think you will have to cut your 5 ft bolt into panels. woops. I was thinking sprit sail here. You will have to make your sail wider than 5 ft. The aspect ratio simplifies to twice the height divided by the width. A 5 ft wide sail with and aspect ratio of 4 gives a 10 ft high sail and only 25 sq ft, much too small. Increase the aspect ratio to 5 and the sail is 12.5 ft high and still only 31 sq ft. Looks like you'll have to make the sail wider than the 5 ft bolt of cloth by cutting into panels. You might want to include a boom in the rig. -- ------------------------------------------------------------------------------ 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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try looking up a freeware program called sailcut. it is a perfect
program for projects like this. William R. Watt wrote: William R. Watt ) writes: shape: ..... I don't think you will have to cut your 5 ft bolt into panels. woops. I was thinking sprit sail here. You will have to make your sail wider than 5 ft. The aspect ratio simplifies to twice the height divided by the width. A 5 ft wide sail with and aspect ratio of 4 gives a 10 ft high sail and only 25 sq ft, much too small. Increase the aspect ratio to 5 and the sail is 12.5 ft high and still only 31 sq ft. Looks like you'll have to make the sail wider than the 5 ft bolt of cloth by cutting into panels. You might want to include a boom in the rig. -- ------------------------------------------------------------------------------ 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 -- remove "abcde" from e-mail address to reply "I think it would be a good idea." Mahatma Gandhi http://www.quotationspage.com/quotes/Mahatma_Gandhi/ (1869 - 1948), when asked what he thought of Western civilization |
#9
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Sandy,
I am curious- did you find this material at Wal-Mart also? Thanks, Carl McCarty sandy wrote: I just bought the material to make the sail for our still unfinished 10' nesting sailboat. I took another look at the material (thin nylon) at Walmart and did find that you could readily blow air through it and quickly decided against it. Then I found material that looks suspiciously like real dacron sailcloth. The clerks had no idea what it was. It's strong (I can't tear a thin sample of the cloth), it melts with a match...and it's much thicker than the nylon material AND you can't blow through it at all. At $1/yd, I couldn't resist it. At that price, I figured it's worth playing with (even if it is bright, BRIGHT yellow). Now I'm trying to figure out how to design the sail. Hubby finally decided that he didn't want the sprit sail and opted for a cat rig instead. This material is 56" wide and I'm wondering if I should just sew the panels together (using the full width of the material) or what??? It looks like most sails use narrower panels but it seems silly to cut the material only to resew it. Also not sure how to go about shaping the sails. I'm thinking of keeping it simple and just sewing the panels flat and shaping the sail somewhat by curving the edges of the sail. Appreciate any suggestions. Not looking for a professional sail...just trying to do the best I can without knowing what I'm doing. Thanks! Sandy |
#10
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Carl McCarty wrote in message
I am curious- did you find this material at Wal-Mart also? Thanks, Carl McCarty Yep....Walmart! I'd really just about decided to buy some dacron...but when I wandered through the fabric section of Walmart, I found this stuff. At $1/yd it's worth it just for the practice....but it looks good. Really curious to see how it all works out. It's really strong (one edge of the fabric was imperfect and "ribboned". I couldn't tear these small ribbons), you can't blow through it, I've tried stretching it and can't notice stretch, and you can melt it with a match. Clerk had no idea what kind of fabric it was. I gathered that they get all sorts of seconds, rejects, etc. Looking forward to raising our bright yellow sail. By the way....Any suggestions for "rings" to connect it to mast & boom? Hubby wants to just use some twine. I'm looking at some plastic shower rings that we've had stored away forever (and thinking of putting in grommets to hold rings). Any other suggestions? (Our mast & boom will be aluminum tubes). Thanks! Sandy Sandy |
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