Sewing marine vinyl requires use of a heavy-duty sewing machine, heavier than normal thread and an appropriately sized needle. Marine Fabricator recommends the use of a commercial sewing machine with a walking foot that pulls the material with the needle as well as the feed dogs. A machine using a single needle lockstitch is adequate for most projects.
Marine vinyl is a much heavier fabric than used in most home sewing projects. Upholstery projects using this material often require sewing several layers, such as with edges that include cording. The force needed to penetrate more than two layers is beyond the capacity of most home sewing machines, especially newer machines that make heavy use of plastic parts.
Bonded polyester thread is essential to ensure the longest life for the completed project. Commercial threads are available in several weights, but v-69 is a good choice for marine vinyl. If using a lighter sewing machine gives unacceptable results with this heavy thread, sizing down to v-46 is sometimes helpful.
Selecting the correct sized needle is key to the success of sewing with this material. Oversized needles punch unnecessarily large holes in the work, allowing water to penetrate through the seams. Undersized needles are more likely to break, especially when working with several layers.