When you buy a sailboat you need to make sail decisions. The first decision comes down to where you sail. If you stay in your local area then any sailcloth can be selected, with the size of your wallet being the only restriction. If you are going to cruise the world, select Dacron sail material. Dacron can be repaired in Cape Town, just as easily as it can be in Newport or New Zealand.
Decide what tools and repair material that your boat will carry for sail repairs, including at least one roll of pressure-sensitive adhesive (PSA) tape (often called Ripstop or Stickyback). You should carry some other basics: a square yard or two of Dacron, maybe a yard or two of spinnaker nylon to suit the spinnakers or light-air sails, some rolls of thread, a few needles, and a single seaming palm. A yacht leaving on a transocean trip might carry a sewing machine (hand or power driven) with a variety of suitable needles, a roping palm, sail maker's tools (and possibly rigger's tools), plus a few yards of Dacron or nylon of a weight to suit the sail inventory.
Most sails rip for two reasons. The first is that it catches on something on the rig and tears. The second is that the sail is old and the material has degraded. In both cases you will have a ragged edge. Drying the sail, then applying PSA is the easiest and fastest solution while at sea. After you've applied the tape, sew over the rip using a zigzag stitch.
If you are out for the weekend and your sail tears, repair it as soon as possible. If you don't repair a small rip there is a good chance that it will grow. Sails don't usually rip when you are sailing, unless the boat is pitching hard and throwing lots of water or spray into the sail. Most often a sail rips during a maneuver or when it flogs. (In the old days, a way for sail makers to test the endurance of a sail fabric was to tie a strip of sailcloth to their car antenna and drive for a few miles. The flogging from flapping in the breeze very quickly broke own the sail fabric.) Flogging degrades sail fabric faster than any other factor.
When repairing sails, use the smallest needle and thread consistent with the strength of the material. A large needle and humongous thread makes big holes in the material, and often an old sail or awning will rip along the sewing line when a large needle and thread are used.
If the sail has a large hole, use a piece of fabric to cover the hole. Tape the edges with PSA tape and then sew the patch to the sail fabric. This gives you a stronger patch than if you cut the patch larger than the hole and simply sew it to the sail. Remember, too, that when you get to port, a sail maker will redo the repair that you made.
When sewing two edges together by hand, use a zigzag stitch or herringbone darn so that the edges are held together firmly. If you are sewing two pieces of material together use a flat seam stitch. Stitches should be pulled hand taut, with each stitch as taut as the others. Rub down each seam after it is sewn to get the stitches to lie flat. Sewing ropes to canvas requires a special kind of stitch known as a roping stitch.
The best kind of stitching is done by a sewing machine. A heavy-duty home sewing machine will do many of the repairs that your sail-covers, bimini, or sail bags require, but if you have to sew heavy sail fabrics, you will need a much heavier machine … or the services of a sail maker.
Roger Marshall has written 14 boating-related books including his latest, "Fiberglass Repair Illustrated."