Making Polytarp Sails

Homemade polytarp sails are affordable and easy to make. They make excelent, durable and proffessional-looking sails!

Polytarp sails have been around for many years. They gained popularity with boatbuilders because they were cheap, easy to make, and made decent sails for one-off amateur-built small boats. When we started designing sailboats we decided to offer sail plans for sewed one-piece polytarp sails. In Brazil sailmakers are few and Dacron must be imported, so usually sails are very expensive. Polytarp, on the other hand, is abundant and cheap, and can be found in all sizes, with good thickness (300 micra, 190 grams/sq. meter).

The original polytarp sails were assembled with double-sided carpet tape, and finished with duct tape. Durability was a secondary concern, since sails were so cheap and quick to make them that replacing sails was routine. But we have found out that polytarp makes a great material for small boat sails. Built correctly, these sails set really well and are quite durable. Best of all, learning how to make these sails is quick and easy. You will need to have a grommet press and a sewing machine that can sew zig-zag. Sewing the boltrope to the sail and sewing the folded edge around the sail takes little time and make the sails waterproof.

We have learned how to design efficient gaff, lug and marconi sails to be built from polytarp. These sails perform really well going upwind and have great overall performance. Best of all, these are sails you can make yourself. If you’ve built the boat, why not rig her yourself too? Another advantage is that, once you learn how to make your first sail, it will be easy to make other sails with larger or smaller sail areas or different designs. You can put as many reefs as you need and make extra reinforcements for heavy-duty use.

Our sailboat plans include instructions for cutting and assembling polytarp sails. The cutting and assembly sequence is shown here:

Check out how efficient these polytarp sails are in this video from our Brazilian Youtube Channel: https://www.youtube.com/watch?v=EBeOzWEz9x0