Post on 03-Apr-2018
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depth should be one inch for each five feet ofluff(or foot). By the way, for now let's call that pointD for now. More about it later.Now you need a gym or a dance floor, or something like that. You can guarantee the owner that you
will not harm it. And you and your helper, ifyou have one, will for sure need a set ofknee pads, like
volleyball players and flooring people use, or you will come away with sore knees.
Be sure the floor is really clean, and not dusty. Lay out the material, and cut it roughly to shape,
leaving maybe a foot ofexcess along the luffand foot. Now lay it down again and use bits ofmasking
tape to hold it stretched out. Ifyour sail is to have a seam, stick down only the large panel. Do not, by
the way, use a lot offorce; you don't want to stretch the material. Now apply the tape to the edge
where the seam is to be. This requires a lot ofconcentration, and is high precision work; take your
time. The tape is really sticky; mistakes are hard to correct. Do not stretch the tape; ifyou do you will
get a puckered seam.
Now get the next panel handy, peel the backing offthe tape you have already laid on the other panel,
and attach it. Also tricky.
Tape down what you have on the floor. Remember, minimum tension, just enough to hold it smooth.
I hope you were able to find a long, flexible batten, and also a long straightedge. With a little ingenuity
and much cussing I was able to make do with an eight foot by one inch strip ofaluminum that you
can find in any hardware store, but maybe you do better than that. Draw straight lines for the foot and
the leach, and also straight lines parallel to them and outside them by the width ofthe tape.
Locate Point D and mark it.
For bending the batten and holding it in place so that you can draw
the curve ofthe luff, you can use. bricks, cans ofpaint, heavy booksor lots oflight ones. But be wary ofthis: the batten will tend to bend
much more at Point D than elsewhere ifyou just pin it down at head,
tack, and Point D, giving you a curve the is not fair. The batten
wants to be bent outward just a little bit more, halfway between Point
D and the corner. Do it.
To do a perhaps better job than you can do by eye, you might want
to mark a couple ofmore points on the curve. Try this. Halfway
from Point D to each corner, measure out from the straight line a
distance equal to 3/4 of(or .75 times) the distance you measured outto find Point D. This will give us a really good approximation ofan
arc ofa circle, in curves ofthe dimensions we are using.
Draw the curve. Draw also a line, like before, outside it a distance
from it equal to the width ofthe tape.
Now you have the choice ofattaching the tape to the edge and then cutting offthe excess Tyvek, or
cutting along the pencil line followed by taping. I say cut first. This can be done best with good, big,
sharp scissors.
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Now you have a sail, and it is stronger and will set better than you think, by a lot.
And now be sure that you haven't left anything sticky on the floor ofthe ballroom- you will want to
use it again. Masking tape leaves little goo behind it, but be sure.
Take pictures ofyour boat sailing under your creation, and give one to the guy who gave you the
material, and also one to the guy who runs the ballroom.
A Few Cautions
You will hate the sound ofthe sail luffing- it sorts ofmakes a rattling sound, it doesn't sound like a sai
at all. But you will grow accustomed to it, especially as you check your bank balance.
Don't attempt to strengthen this sail by running the seams and edges through a sewing machine. The
stickum on the tape will gum up the needle immediately. Ifyou really want to sew the seams, make
them a lot wider than the tape and sew through the Tyvek, but not through the tape. Any batten
pockets you may want should probably be stitched.
The material is rather stretchy. It isn't as bad as the light nylon they use to make sails for boats like aSunfish, but it is nowhere nearly as inelastic as Dacron. When it is blowing hard the sail will get
slightly more full.
It turned out that the mast I made was a lot bendier than I had expected, and in any breeze at all the
sail looks lousy- although it sure does drive the boat. On my next sail I am going to move Point D
farther up the luffand make the curve deeper. Likely you will do something like that, too.
From making the first sail you will learn a lot about making the next sails better and faster and more
easily. And you will probably want to start by calling up DuPont and asking for sample materials and
prices. They make the material in a lot ofdifferent weights and textures, and different widths. Butyou'll have to buy a lot of it, probably a roll ofat least a hundred. feet; it is still very cheap, however.
I have no idea how big a sail can be made in this way and still not blow apart. Bernie Wolfard writes
ofa 40+ foot schooner with Tyvek sails as big as 300+ square feet. Reinforcements could be bigger,
seams could be made oftwo widths oftape, etc. And it is a truly minor disaster to have such a sail
blow apart, most ofthe time. Have oars or a motor.... This is going to be cheap and fun and
interesting. Set about it.
Bill Wallace
3430 Miramar Drive
Shoreacres, Texas 77571Copyright 1998 by Author
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