I have a old copper t-joint behind my hot water heater that has a small leg that comes off for the top of the water heater. The pipe has developed a small leakat the top of it. It only leaks about 2-3 drops a day but it has been going on for awhile since there is some calcium built up on the outside of the line. I know I will have to drain the tank to move it and I will have to drain the lines. What I need to know is can I unsolder the pipe that is leaking and clean the joint and put a new piece of pipe in. The part that is leaking is only 12 inches long. The other 2sides of the joint is ok plus one goes through a wall and would be very hard to repair.