i bought quite a bit of lead water line that had been replaced back in the 80's and as I recall it had thick mineral deposits in it that was already decreasing the ID of the line. I'm thinking that even if your could reline lead water service lines that it would greatly restrict the flow of water to a home or business. I've seen it used to reline leaking sanitary sewer lines, but they were much larger in diameter. i wish now i had segregated the ingots i cast into reclaimed lead water line and separately plumbers lead joints from smashed cast iron pipe from an old orphanage and an old seminary that were being demolished to develop subdivisions. I was just gathering plenty of lead to cast muzzle loading balls from.