Tried using a blue painters masking tape at the beginning and end of the length to be sewed and pins between. The tape didn't stick to the silnylon very well. More of a inconvenience than help. Looking like pins are so far the best solution.
At a kite building site they noted the use of a "spot" welding device to spot weld ripstop nylon together. Anyone try such a tool. Might be quicker than pins and keep that initial and last inch of silnylon aligned.
The Singer I own is a model 15-91. Pre WWII build. Don't know if a walking foot designed for this classic is available. There is a site called sew4less that had parts. Have to check it out for a walking foot. Switching from the cheap Coats poly thread (fuzzy) to some thread purchased from RayJardine required bobin case tension adjustment. That was a bit of pain. Also, the #12 needle and thread combo was a problem. #14 works fine. So my machine problems have been solved. My sewing skills still stink when it comes to silnylon.
Day & night temps have really cooled down recently. Rain has shown up regularly for the first time since spring. A rain kilt would be real nice. It's hunting season up here. Blaze orange rain kilt flashing in the woods should reduce the chance of experiencing getting shot at. Any source for blaze orange silnylon?