- 1). Spray WD-40 lubricant inside the copper pipe.
- 2). Place the wider of the two dowels inside the copper pipe.
- 3). Place the tip of the narrow dowel against the end of the wider dowel.
- 4). Tap the opposite end of the narrow dowel with a rubber mallet to push the wide dowel through the length of the pipe. The wide dowel will push out the dents as it passes through the line.