Duckworks
entry Sails! -
Sailing bits, and polytarp sail making.
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This shows how the poly tarp is cut to get the sail to fit. Poly tarp is easily fastened to itself with double sided exterior carpet tape. It is fiberglass reinforced and exceptionally strong. You can stitch on top of it if you're a "belt and suspenders" kind of person. The photos below show using a 9x12 tarp, but you could start this way. Original sail dimensions are provided too. |
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 Here
are sketchs with side lengths. |
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I marked the length of the sail's sides on wood strips and then did a trial layout. |
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I use 3/4" PVC pipe to layout the curves of the sail edges. Here I'm drawing the shape of the head or top edge of the sail. This edge will be attached to the upper spar by rings or ties. I held the pipe in position with weights then traced its curve lightly. (Head or top of the sail curves out about 3 inches and the leech or trailing edge of the sail curves in about 2 inches.) If she needs more shape I'll try the little edge pleats that Dave Gray uses. As you might suspect, I try simpler first and get complicated only if necessary;-) |
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After tracing the pipe, I apply double stick fiberglass reinforced carpet tape on the outside of the line. An artist brayer helps apply it smoothly. |
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I then cut along the outer edge of the tape. (A foam pad or knee pads is handy for this part. You'll do a lot of crawling around.) | 
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I use the brayer again to form a crease along the inner edge of the tape. |
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Then, a few inches at the time the backing is peeled and the tape is rolled tight. |
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Along the head of the sail place 1/4" bolt rope to help take up some of the stress and also keep the sail rings from pulling through. Some put bolt rope around the whole sail, but I've been told the smoother the air flow over the leading and trailing edges of the sail the better. Besides that fiberglass reinforced tape lends amazing stretch resistance to the sail material. |
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I have previously melted through the sail just inside the bolt rope with my soldering iron, but this time I used the tip of my glue gun to melt it slightly, followed by an awl. These rings are actually sold for shower curtains. (OK, don't laugh, they work!) If these don't fall under the catagor of "fasteners" in the rules, short lengths of the 1/4" rope would work fine too. Though I couldn't make hot melt glue work for the seams, it seemed to work fine for the corner reinforcements, and tacking down loose corners. |
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This shows a "fair lead" created by drilling a hole through the tiller handle then rounding the edges with 3/8" quarter round a router bit. The main sheet and the tiller can be controlled with one hand, and the hole is positioned so you can pinch the sheet between the tiller and the top of the rudder head. Lift the tiller and release and the line runs free. Regular pintels and gudgeons could be used. Here I use the double taper block approach. If loose footed, skip this and sheet to the transom corners for best sail trim. |
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Within the
rules I could take the taper trim pieces from the mast, glue the sawn
faces together making it a rectangle then laminate into a 2x6 10"
long.(Could happen!)
If this seems too far fetched materials use, substitute stainless or bronze pintels and gudgeons - but this wedge gizmo works great! |
In this 10" piece of 2x6, I cut a 7/8" deep saw kerf down the center. The yellow dotted lines
shows how I taper the insert. In instrument building
this trick is used to join necks to bodies. When you insert it it will
snug it up against the transom. Way easier then hanging over the stern of a
small boat trying to line up pintels, I promise!
This could all be done with a hand
saw, but I used the table saw. I don't own a taper jig. But here's an easy way
to cut a taper using a scrap of plywood. I set the saw to 25 degrees and clamped
the fence about 5 inches away. I ran a scrap of plywood throught the saw. I then
lined the cut edge of the ply up with marks I made on the BOTTOM of the wedge
stock. I stapled it in place with 1/2" staples and ran in through the
saw. I then pulled it off and stapled it to the other line. Works great.
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Here's the wedge with the seatbelt webbing trial fit in the saw kerf. Ultimately I glue it in with PL Premium and anchor it with some small ring nails for "safes." Is seatbelt a fastener? Could melt a bunch of short pieces of 1/4" rope together..... hmmmm.... |
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Here are the receivers trial clamped to the transom. |
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I shortened the receivers so the wedge is longer so I could tap it loose if it should get stuck. I've also rounded the edges and sanded them some. |
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The leeboard idea I got from my friend Richard Frye. It will work with internal chine logs or stitch and glue. The board bolts flat against the side with a plastic spacer to reduce friction. It "bump" stops against the gunnel in the down position. |  |
There is a simple 1/2" hole drilled in the top of the mast for the halyard. It is rounded with a 3/4" quarter round router bit. Just above the mast partner two wooden cleats are screwed on either edge of the mast. One is for the halyard and the other for the down haul.
A simple snotter tensions the sprit
boom.
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Here she is rigged, in the sprit boom version. |
In spite of no wind I was determined to
sail.
So we went out.
We came back. The breeze was almost
theoretical it was so light, but she slipped along nicely. Since then I've had her
out in a few good breezes and according to my Garmin GPS we hit 7.5 knots quite
a few times. We must have
been planeing though I didn't feel it.
She
patiently awaits a captain...
Shucks, if only I hadn't run out of time, I could have used that extra 8x10 polytarp for a camping cockpit tent!