I have a friend that repairs guitars and he has a guitar that he is working on that has frets that are difficult to make from scratch (which is what he usually does) so he was wondering if it would be possible to TIG in some filler on the old frets (which he will remove). He called the fret wire nickel silver so I looked up what its made out of and there is no silver, just brass and some nickel to give it that silver look. My question is, what could I use for the filler? I tryed looking it up but all I could find is allot of rod # that was used for welding cast iron and pipe. I was hoping maybe someone could steer me in the right direction.