My seven string guitar has a problem. The low B constantly goes out of tune. Whenever I bend it, I immediately have to re tune it. The place I bought it said it was probably the nut but I am not understanding how that could be. Is there a quick fix without having to take it to a shop? I live a long way from one. Thank you guys
Since you stretch your strings and would prefer not to have your guitar worked on at a shop, a quick fix would be a lubricant.
Before the Floyd Rose tremolo system existed, lots of players would apply lubricants to the nuts of their guitars as needed. This allows the strings to slide through the nut when bent or when used heavily by a whammy bar. Van Halen has mentioned in numerous interviews his hassle to keep his guitar in tune pre-Floyd. Even players without locking string systems, like Guthrie Govan, have mentioned the necessity to using string lubricants to allow them to play "irresponsibly."
You can either make your own or order a notable brand (Big Bends Nut Sauce is very popular). If you want to experiment and make your own there are many different "recipes" out on the web, but the majority of them consist of the lead from a pencil mixed with vaseline to make a paste. Some people even use Teflon Oil.
A warning: when you apply anything to your guitar, do it sparingly.