To repair a tear in a convertible car top, sew the tear together, attach a piece of masking tape on the underside of the tear, and apply some glue to the upper side of the tear. Cut out a piece of marine canvas, and replace the masking tape with this patch. Apply some glue to the stitching holes around the patch, allow it to dry, and remove all the excess glue using sandpaper.
Use a thick and strong curved needle together with strong thread or thin wire to sew the tear together. This process usually takes a lot of time to complete, but it is necessary to take the time and stitch up the tear properly. Use a cross-stitch pattern all the way along the tear. Try to sew the tear together closely and very tightly.
Placing masking tape on the bottom of the tear keeps excess glue from dripping all over the car. Generously cover the seam and the area around it in heavy duty glue. When cutting the canvas, try to create a shape that is similar to the shape of the tear, however, it needs to be 1 to 2 inches larger than the torn area.
Sew the replacement patch onto the tear once all the glue has dried. Once the repair is complete, cut away any excess fibers and other materials.