Hello! I have a sling bag that I really like, but the strap doesn't take it as close to my body as I would like. I have a sewing machine, but I have never used it for stitching seatbelt webbing. What sort of needle would I need to use, and which type of thread would be best suited for the material?
You can try a heavy duty needle, but there's a pretty good chance a domestic sewing machine just won't work with seatbelt webbing. I'd recommend caution
Snapped needles are the most likely thing that could happen.
Sometimes people assist the motor by turning the hand wheel, and I've heard that can bend the frame of the sewing machine in some cases. That'd be the most catastrophic failure potential I think
I’ve used a regular machine with a denim needle to sew a couple nylon webbing layers together. I don’t know how sturdy you need the thread to be but general utility thread should work for a basic bag, or you could get a spool of Gudermann(?) thread for a step up.