How to Cap off the Pipes to a Sink

Clean the ends of the pipes with an emery cloth and the inside of the caps with a round wire brush. This removes any grease or corrosion from the copper, which allows for a better connection.

Apply flux to the ends of the copper pipes and the inside of the caps. Flux is a chemical cleaning agent that assists in the soldering process.

Slide the caps onto the ends of the pipes.

Light a blowtorch and hold the flame against the joint for four to five seconds to heat up the copper. Hold the flame on both sides of the pipe to ensure even heating.

Place the tip of the solder against the joint between the pipe and the cap. If it doesn't melt immediately, heat the pipe with the blowtorch again.

Hold the blowtorch against one side of the pipe and place the solder against the joint opposite the flame. The solder will flow into the joint as it melts. Allow the pipe to cool for at least five minutes.