I have used a sewing awl with wax impregnated string. It generally looks like crud, but so far no failures. It is as strong as it gets and if it can penetrate leather, it can certainly sew cordura. I do a lot with webbing and I am getting pretty good at it after some practice. I bought extra spools and wound them on the bobin winder-thingy on the wife's sewing machine. I keep it in the BOB and if I ever have a failure I will be able to fix it and carry on. It is a good skill(?) to know. I tried to sew an interior pocket into my BOB with my wife's sewing maching and after a package of needles and a barage of "if you break my sewing machine..." I went back to my trusty awl. Just a thought.