Step 3 · Deburr and Clean

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.

After cutting, a small ridge of copper, called a burr, is left on the inside edge of the pipe. Use the triangular blade on the tubing cutter or a dedicated deburring tool to ream the inside of the pipe and remove this burr. Next, aggressively clean the outside of the pipe end (about 1 inch) using sand cloth or a pipe cleaning brush until the copper is bright, shiny, and free of any tarnish or oxidation. Then, use a fitting brush to clean the inside of the copper fitting with the same thoroughness until it also shines. Wipe both surfaces with a clean, dry rag to remove any copper dust. This cleaning step is absolutely critical for a successful solder joint.