Anyone ever done it? I am working on a custom R1200RS project, and it may involve modifying a R1200R fuel tank because I want more capacity. I would think it can be enlarged by, in a sense, cutting off the top almost around the outermost edges, angling that portion up, and welding in metal to fill it back in. Given the thin metal of the tank, I'd assume it should be TIG welded to minimize heat/warppage.
Anyone ever try this or know someone who has had success with it?