I "hot tack" nylon when I sew it. I converted a soldering iron to a hot tacker by adding a simple coil spring. You simply touch the iron every few inches to the fabric and it basically spot welds the two sheets together with tiny little weld dots, strong enough to get it sewn. Just pull it apart if you get it wrong, and re-tack. I make kites and that is by far the best way to "pin" synthetics.
I also use the same tool, spring removed, with a straight edge to hot cut my fabric. Eliminates frayed edges.
Like this: https://sites.google.com/site/kites4all/home/hot-tools