Gone Outdoors

How to Make a Sailboat Sail

by Tom King

Sails are quite an expensive item to replace, but you can save yourself a lot of money if you'd like to try your hand at making one yourself. A unique and easy-to-make sail can be constructed of Tyvek, the amazingly tough and resilient material used to wrap houses.

Sail diagram

Create a pattern for the sail. Either use your old sail for a pattern or draw it out in chalk on a large, flat concrete surface or floor. Use a chalk line to mark the edges. To mark a curved section on the mainmast side for the luff of the sail, select a point.

Edge seal

Cut the Tyvek with very sharp scissors. The material is very resilient to puncture and difficult to cut. Allow a minimum of 2 inches of overlap for the seams and edges. For edges that will be attached to a spar, allow 4 inches or better to wrap around the rope that makes the foot of the sail. If you need a seam, make it parallel to the leach of the sail (the hypotenuse of the right triangle of the sail). This reduces pressure on the seam.

Lay out the sail on a clean flat surface and cut it roughly to shape. Leave a foot of excess material along the luff and foot (bottom of the triangle). Tape the sail to the floor using masking tape to hold it down.

Taping the seams

Apply one side of the double-sided tape to the edges and any seams. Go slowly and don't stretch the tape or allow it to wrinkle or the seam will pucker.

Trim the corners before sealing seams

Trim the corners to avoid an unsightly lump of tape where the seams meet.

Leave slight overlap if you plan to reinforce with stitches

Overlap the second panel (if needed) and place is so it can be moved into place and taped down. If you plan to stitch the seams, add an extra ½- to 1-inch overlap for the seam. Do not stitch over the tape or the machine will be jammed.

Carefully remove the tape and press down the seams and the edges. If you cut carefully, the seams should line up perfectly, otherwise cut off excess with very sharp scissors. Do not tape the foot of the sail yet if you are folding a rope into the foot to attach to the spar.

Prepare reinforcement patch

Reinforce each point where you are going to attach a slide, grommet or reef point. For grommet points cut a square of Tyvek, round the corners and then cover one side with double-sided tape.

Fold the reinforcement patch over the edge at the point where the grommet will go. Cut the hole as described in the instructions that came with the grommet kit and pound the two halves of the grommet together over the hole.

The roped foot seam

Prepare the foot or leach of your sail where it slides into the spar or mast. You'll have to wrap up a rope of appropriate size into the foot or leach of the sail. Apply double-sided tape along the edge of the sail, lay down the rope in place and wrap the edge around the rope. To strengthen the edge, you'll need to stitch the seam above the rope, then apply a sealer or epoxy around the seams to protect them from hard wear.

Items you will need
  • Enough Tyvek sheets to make the sails
  • Double-sided Tyvek or carpet tape as wide as you can find it
  • Scissors
  • Chalk line
  • Long straightedge
  • Rope for foot and/or leach as needed
  • Grommets

Tip

  • You may need to seam the Tyvek for larger sails. You may be able to find enough leftover Tyvek from a home construction site to do the job.

Photo Credits

  • All images (c) 2009 by Tom King