Tips for Window Replacement in Canvas or Sailcloth

Item # X-HT-200289

The polyvinyl chloride material that is most popular for windows (alternatives tend to be either very expensive or rather inflexible) is not as resistant to sunlight as sailcloth and canvas. As a result, it is usually necessary to replace it two or three times during the life of a sail or a dodger. Replacing a window is actually rather easy. There are, however, some tips that we can pass along that will make the finished job look just as good as the work of a professional.

When selecting a window material, it is important to consider durability and optical clarity. For higher quality and superior optical clarity, Sailrite recommends using pressed, polished vinyl window material from brands including Strataglass™, Crystal Clear, Kal Glas, Regalite® and O'Sea®. Sailrite's own Plastipane clear vinyl is reasonably priced (per foot) but lacks the durability and clarity of a sheet good. Therefore, we do not recommend it for boat windows where you need superior clarity, visibility and durability.

When installing a new window, be very careful to keep the surrounding fabric flat and relaxed. If there is any bias stretch in the material, there will be a tendency for the new window to have diagonal wrinkles. The best way to avoid wrinkles is to remove the old window only after sewing the new one in place. The old window, unless split, will keep the panel from stretching on the diagonal. Make the new window about 1/2 inch larger than the old window all the way around.

If the old window is torn or split or if there is no excess material to allow for a larger window, the old window must be removed before the new can be installed. Be very careful when lining up the new window to position it on a flat and relaxed panel. Use push-pins to hold the fabric down on a plywood board to hold everything in place.

Basting the new window in place is very important as it is almost impossible to sew a window in place without skewing the placement or creating bubbles. Apply the acrylic basting tape all round the new window and even staple the window at foot length intervals for a secure hold. Use a walking foot sewing machine if possible to ensure the layers of material feed through at the same time. If using a regular machine, feed the application through the machine with the window material down so the feed mechanism pulls directly on the "sticky" plastic. Although not visible, the edge of the window can be felt through the fabric to guide stitching placement. If for some reason the plastic must be on the top, sprinkle baby powder over the surface so it slides along more evenly.

Do not sew all the way around the window in one pass. Sew down one side at a time and parallel sides consecutively. For example, roll a dodger panel up from one edge and sew along the closest window side. Finish that stitch with a short reverse at the beginning and end. Then continue rolling the panel to the other parallel window side and sew it. Pull the panel out from under the machine and roll it the other way sewing the last two parallel sides. This technique makes it easier to keep the window from breaking loose from its basted position.

The window edges can be trimmed out in any number of ways. The inside edges can be covered or left uncovered depending on your preference. The fabric side of the window edge, however, needs to be finished. Roll the edge under and sew down if there is sufficient cloth (hold the edge down with basting tape). If there is not enough extra material, baste a 3/4 inch binding tape flat on the rim of the window and sew down with two rows of stitches. Binding tape comes with two pre-folded edges so it provides a nice finished appearance with very little work.

Now that you've learned all about vinyl window material, explore our inventory of how-to blogs that teach you how to replace the vinyl windows in your sails and boat canvas enclosures.