Although it isn’t difficult to remove and replace a piece of copper pipe, you do need some supplies that not everyone has lying around, such as a copper-pipe tubing cutter, flux and a flux brush, solder, and a propane torch.
To remove and replace a damaged piece of pipe, follow these steps:
Turn off the main water shut-off valve; then open a faucet at the lowest point in the home.
This drains the water from the pipes.
Use a measuring tape to determine the length of pipe needed and use a pencil to transfer the measurement to the new pipe.
When figuring the overall length of the replacement piece of pipe, make sure to take into account the ends, which will slide into fittings. The total length of the replacement piece of pipe and the two couplings, when fully assembled, must be about 3/4 inch longer than the length of the damaged pipe.
Place the blade of the tube cutter over the mark on the pipe and gently clamp down on the pipe by turning the grip clockwise while rotating the cutter around the entire circumference of the pipe.
The cutter should move freely. Applying too much pressure too fast will bend the end of the pipe and damage the cutting blade. A bent end can result in a leak.
Use the deburring blade or a small file to remove any burrs at the cut end.
The deburring blade is located at the end of the tube cutter.
Polish the outside of the end to be soldered with emery paper until it has a bright finish. Do the same with the interior of the fitting to which it will be joined.
This polishing cleans the material and provides the necessary tooth for a solid connection.
Apply a thin layer of flux to the outside of the pipe and the interior of the joint.
Flux is an acid that further cleans the pipe and causes the solder to flow more evenly.
Assemble the pieces and rotate the pipe in the fitting to distribute the flux and ensure a secure fit.
When working near wood, use a metal shield between the flame and the combustible surface to avoid causing a fire. Never use a torch around natural gas or gasoline, and always have a working fire extinguisher nearby.
Solder the connection.
When soldering, wear safety glasses and gloves, as well as long pants and a long-sleeved shirt to avoid being burned by hot flying flux or solder.
Soldering is not like welding, where the flame is placed directly on the connection. When soldering, the tip of the blue flame should be directed at the fitting, not the pipe, which allows the heat to radiate to the joint. When the flux begins to bubble, touch the end of the solder to one point of the joint and let capillary action do the work. The solder will automatically form a tiny bead around the joint. Remove the flame as soon as the solder begins to flow. Be careful not to move or jiggle the pipe or fitting for about a minute after the flame has been removed — you want to allow the solder enough time to cool.
When the soldering is complete, remove the excess flux by wiping off the pipe and fittings with a clean, dry cloth.
Turn the water back on.
Be sure to check for leaks.