This weekend I want to remove a redundant length of (nearly horizontal) 4.5" iron soil pipe. It joins the stack into an iron socket.
I anticipate I won't be able to remove the pipe from the socket cleanly, and expect to need to use a disc cutter to tidy up the end once I've removed the pipe (probably via judicious use of a sledge hammer to encourage brittle fracture).
Is there a preferred technique for sealing the resulting hole?