Sail and Rigging
This simple, classic balanced lugsail which dates back at least to 1890, provides a lower center of effort along with much better upwind ability than an equivalent triangular sail, and there's a reef point in case you get caught out in a rising wind. The design has been successfully used on dinghies, canoes and many other small boats with excellent result.
Inexpensive polytarp is used in this example, but could be easily replaced with a more traditional sailcloth later if desired. Look for polytarp (used for covering automobiles and equipment outdoors) that says it is UV (ultraviolet) resistant. Usually they have a number of grommets already installed its edges for tying. You will need polytarp 8' x 7' (about 2.5 x 2.2 m) or larger.
The dimensions of this rig are such that it will be the same or less than the collapsed Flapdoodle for storage. Of course you can make it larger if you wish.
.Bundled rigging.
Yard Arm
Begin by making the yard, since the sail must match its width. I devised this method for the yard to make it more suitable for a collapsible boat; strong, light, and no adjustments required to put it back into service quickly.
Two pieces of straight wood molding 7' (217cm) long were chosen with no knots. The shape resembles below, but a hand wood plane was used to round the edge shown on the far left to make it a little more aerodynamic.
The purple line is fiberglass reinforced carpet tape.
Drill and countersink holes on ONE strip for #6 x 5/8" flat head brass wood screws. Re-sink any screws whose head sticks up above the surface. Align with the other strip, and attach with the screws.
Once assembled, it will be easy to plane and sand so that the two halves will match and have a pleasing shape. Sand the sharp edges on the ends round.
Disassemble, varnish (including what will become the inner surfaces), and allow to dry.
Choose Decide which edges will be the luft, and leech. If you use the factory edge of the polytarp for the leech edge (the edge toward the rear) of the sail, you will have less seaming to do, but it may have objectionable grommets.
Laying out to see how it will fit together...
Cut a shallow angled groove in each end of the yard half that does NOT have the screw holes. They will be approximately at a 45° angle.
Check to make sure the line will fit flush in the groove.
Apply double sided fiberglass reinforced carpet tape to this side only. It may help if you cut the top (angled part) of the sail first to the rough size to make it easier to handle.
Start at the edge you chose that has the factory seam, and press it into the groove. A friend may be necessary to help pull the edge tight as you work. Gently press the sail onto the tape. When you are sure it is straight, press harder to make it adhere firmly.
When you get to the other unfinished edge (either the luft or leech), apply tape to the edge of the sail with the tape centered over the notch. Press 1/8" nylon line into the groove, then work your way downward.
If you are satisfied that all is straight, fold the edge of the sail over the tape to seal it with the line trapped inside. You can now attach the other half of the yard with screws. Trim the excess sail from the top of the yard arm with a razor cutter, and leave some of the 1/8" line at the bottom. This will be used to pull the edge tight later as an adjustment.
A halyard swivel was made from a bail from an old plastic bucket. Brass brazing rod about ~1/8" (3.5mm) would probably be better. It is a loose fit inside a piece of brass tubing. Drill a hole through the yard 29" (73.6cm) from the fore end the diameter of the brass tube. The swivel is designed to prevent twisting of the yard.
Holes are drilled for the parrel line 8" and 10" (20 and 25cm) from the fore end. Nylon or poly rope are slick on a varnished surface and will let the yard slide smoothly up and down.
Boom
Select a clear piece of fir or spruce 8' (2.4 meters) long and 1" x 3/4" (2.5 x 2cm). I ripped mine from a fir plank so I could get straight grain.
Cut a notch in both ends as above. I used the table saw. It was difficult though. The notches were sanded smooth with sandpaper wrapped around an old file. A router was used to radius the edges, but sandpaper is safer.
A reinforcing strip of oak scrap was glued to the boom as shown below.
Holes for the parrel line (about 1/4" (6.5mm) were drilled through the boom and reinforcing strip. The strip is there because if the boom is going to break, this will be the location.
You have everything you need now after you add a pulley block and cleat to the mast.
Hint: When you have tried the new rigging out make note of where the mast touches the yard and boom. Cut a piece of plastic from an old jug and attach a strip with the carpet tape to help protect the yard and boom.
This set of plans and all its contents © Bill Weller 2006-2007
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