As the title suggests, I'm looking for some help with my guts. Specifically, my Lenzner G. I've been oiling it using unscented almond oil, trimming hairs and sanding it (using very fine sandpaper) to keep it as smooth as I can. I don't have much experience with guts but lately it's been buzzing so badly, particularly around the Bb in thumb position, that the note is almost indiscernible. It's not an old string so either I've been doing something wrong in maintaining it or there's a flaw in the string itself. The bass is fine as far as I know, I had the fingerboard planed by a very good luthier whom I trust only a few months ago. My suspicion is that perhaps I've been too generous with trimming and sanding it. My gut D is behaving well enough. Is there anything I can do to save the string?