The main soil stack in my 40+ year old two story home has developed small crack. I have seen evidence of a very small amount of leakage in my basement over the past few years, but it was never bad enough to goo cutting into the walls to find the source. Finally it has gotten bad enough that it had to be found. After cutting several access holes in the wall board, I discovered that a hairline crack, approx 1" long has developed in the 3" copper stack. I don't want to solder it, or cut in a coupling if I don't have to. What would be the best solution for this repair?