Has anyone else noticed how stainless hook flies tied with synthetic hair (Ultrahair, Congo Hair, Super Hair, etc) tend to rust? Even if they've never been wetted, sitting in a fly box in a humid garage the s/s hook eyes and shanks will take on a rusty coating, and the hair will discolor. Even saltwater doesn't do this to them using real bucktail. Is this some sort of chemical or galvanic reaction? I kind of like tying with synthetics, but it's just not worth it if my flies are going to rust before I use them.