Step 6 · Heat the Joint

This is the step most people slow down on. Take it one move at a time — there’s no rush, and you can rewind the clip as many times as you need.

Place your heat shield behind the joint if near flammable materials. Unroll about 8 inches of lead-free solder and bend the end 90 degrees. Light your propane torch, adjusting the flame so the inner blue cone is about 1-2 inches long. The tip of this inner cone is the hottest part. Apply the heat to the joint, focusing on the middle of the fitting, not on the pipe. The thicker metal of the fitting needs more heat. Sweep the flame back and forth across the fitting to heat it evenly. The joint is ready for solder when the flux begins to bubble and smoke, and the copper takes on a slightly hazy appearance. You can test the temperature by briefly touching the solder to the joint on the side opposite the flame; if it melts instantly, it's ready.