I was just poking around on the internet and found some info on cutting/sewing ripstop. http://www.xs4all.nl/~pdj/starting.htm
This fellow uses an old Weller soldering gun. He just pounded the tip into a disc shape, filed it to a knife edge and away he went. He actually used wire, seemed to be about 12 gauge. I have an old soldering gun and tried it and when you develop the proper speed the fabric looks like it has been cut with a razor and it is sealed. You need to have a gun and not a pencil type iron and it must have a double heat range trigger. Use it on the first range which is about 20% I am pretty sure I will be putting away my lighter for good!!!