To solder copper pipe, polish the joining surfaces, apply the flux, heat the joint and apply solder. Each joint requires a few minutes to complete, but the time for the overall project depends on its complexity.
- Polish the copper
Cut the pipe to length, and remove burrs resulting from the cut using a utility knife. Polish each end using an emery cloth to remove any tarnish. Use a round wire brush to polish the inside surface of the fitting.
- Apply the flux
Use the flux brush to apply the material to the inside of the fitting. Place the fitting on the pipe, and twist to ensure an even distribution of flux. Use a rag to wipe away any excess flux. Repeat for each pipe in the fitting.
- Heat the joint
Light the propane torch and begin heating the fitting. Direct the flame so that its midpoint is on the opposite side of the fitting from the torch.
- Solder the joint
When the flux begins to bubble from the fitting, remove the torch and touch the end of the solder to each pipe at the edge of the fitting. If the copper is hot enough, the solder melts immediately, and capillary action pulls it into the joint. Apply the solder to each pipe in the joint.