Tom, I'm no plumber so I won't give you any plumbing advise but I will tell you this. Are you using a grinding wheel ( you know knid of looks like a round stone about 1/2 " thick) Becuse if you are you will be there for the next milenium. What you need is a cut off wheel ( round disk about
1/16" or so thick) this will act more like a saw blade and take a hell of alot less time to cut through the pipe.Bill