Step 5 · Clean and Deburr Pipe Ends

This is the step people usually slow down on. Go finger-tight first, then a quarter turn. No rush — replay the clip whenever it helps.

The newly cut ends of the cast iron pipe will be rough and have burrs. For the coupling to seal properly, these ends must be cleaned and smoothed. Use a half-round metal file to smooth the sharp edges on both the inside and outside of the pipe ends. Afterward, take a wire brush and vigorously clean the outer surface of the pipe for at least two inches back from the cut. Remove all rust, scale, paint, and grime. The surface where the rubber gasket will sit must be perfectly clean and smooth.