How to Install a Vinyl Window in a Sail

Item # X-HT-200266

Visibility is key when you’re on the water. Installing a window in your sail makes sailing with large, deck-sweeping sails much safer. In this blog, we’re going to provide you with step-by-step instructions, along with a convenient how-to video tutorial, detailing how to install a vinyl window in your sail. We’ll also include a materials list of all the supplies you’ll need for this project. Let’s get started.

A window installed in a sail.

The best placement for your window is determined while sailing. Avoid making the window larger than necessary since vinyl window material is relatively heavy, and keep the window at least 6 inches from the sail’s edge as the window material stretches more than Dacron sailcloth. Also keep in mind that increased heeling will change the line of sight upward, meaning the window placement would be higher than normal.

Sewing a Window in a Sail

1. Determine the length and width of your window. Mark the location on your sail with a pencil, adding approximately 1/2 inch to the length and width for your seam allowance. Cut the vinyl material to that same size.

2. Adhere 1/4-inch Seamstick Basting Tape around all four sides of the window material approximately 1/16 inch from the edge of the vinyl. Do not adhere the basting tape more than 1/4 inch away from the edge.

3. Next, place the window material on your sail basted side down using the pencil marks to match up the window to its correct placement. Before removing the basting tape, cut a slit in the sailcloth in the middle of where the window will go. This will make it easier to cut out the sailcloth after the window has been sewn to the sail.

4. As you slowly peel off the paper backing and baste the window down firmly to the sailcloth, make sure to smooth out any wrinkles in the sail as you go. Take your time doing this. You want the window material and sailcloth to be nice and flat.

5. Take your sail to your sewing machine and sew a zigzag stitch around the window. A zigzag stitch distributes the stress of the fabric over a broader area. If you don’t have a zigzag sewing machine, two rows of straight stitches will also suffice. Set the zigzag stitch to 3/16 x 3/16 inch (or the longest straight stitch length). Reverse stitch at each corner of the window to lock the stitches in place.

6. Once the window is sewn in place, flip the sail over and cut out the sailcloth, using the slit you previously cut to lift the sailcloth away from the window material to avoid scratching it. Don’t cut too close to the zigzag stitches; leave about 1/8 inch. Cutting with just the tips of your scissors will also help prevent scratching the window material.

7. For larger sailboats over 20 feet, you can add a second row of zigzag stitches if desired. If sewing two rows of stitches, leave 5/8 inch of fabric from the first row of stitching. Sew the second row of zigzag stitches inside the first row, leaving approximately 1/8 inch of fabric at the raw edges.

Here’s a short video showing the window installation process on a Sunfish sail. We hope these instructions and video help you install a window in your sail! Let us know if you have any questions in the comments. We’re always here to help!

Materials & Tools List:

  • Sewing machine (zigzag recommended)
  • Regalite 20 Gauge Window Material 29” x 68” Clear (#103723)
  • Seamstick 1/4” Basting Tape for Sailmaking & Vinyl (#20306)
  • V-69 or V-92 thread
  • Ruler, pencil, scissors