How to Connect Copper Water Pipes

Water supply plumbing in most of the United States is done with copper pipe and copper fittings. In many parts of the country, copper pipe is required by plumbing code ordinances. Other types of water pipe that may be used, but these have once again been called into question for their safety. Joining copper water pipe requires brazing it together, called "sweating joints" in the plumbing trade.

Difficulty: Moderately Challenging

Instructions

Things You'll Need:

• Copper pipe
• Copper fittings
• Emery cloth
• Fitting brush
• Flux
• Flux brush
• Lead-free solder wire
• Propane or mapp gas torch
• Wet rag

1. Clean the copper pipe ends and fittings. Wrap the end of the pipe with a 1-inch wide strip of emery cloth and briskly rotate the pipe within the the cloth until all signs of oxidation are removed. The copper will be bright and shiny. Use a fitting brush to the clean the inside of the fitting in the same way.

2. Coat the end of the pipe and the inside of the fitting hub with solder flux. Use the flux brush to evenly coat the surfaces that have been cleaned.

3. Seat the pipe into the fitting hub all the way.

4. Straighten 10 inches of solder wire, but do not cut it from the spool. At the end, bend the wire in a rough L or U shape so you can easily touch the wire to the back side of the joint.

5. Light the torch and adjust the flame so the bright blue center is 2 inches long. Apply the flame to the front of the fitting hub. Move the flame around the fitting hub to help it heat evenly.

6. Test the temperature of the pipe by touching the tip of the solder wire to the pipe where it enters the fitting. Touch the wire to the back side of the joint, away from the flame. Do not use the torch to heat the solder wire. If the solder melts and is drawn into the joint, the temperature is right.

7. Apply solder to the pipe at the juncture of the pipe and the fitting. Run the tip of the solder wire around the pipe and the fitting hub. Remove the torch flame from the fitting and ensure that solder has been wicked into the fitting all the way around.

8. Wipe the joint with a wet rag to remove flux residue and then allow it to cool completely.

Tips & Warnings

• Sweating joints is not very hard. It might take two or three tries to get it right, but once you get it, the rest will be easy. Have all your joints prepared and sweat them all at once, rather than one at a time. The job will go faster and your joints will be neater. When you wipe the flux residue from the joint, be gentle. The solder inside the hub is still liquid, just becoming solid. You want to clean the joint, but if you're rough, you could cause cracks in the solder which will make the joint leak. Joining two vertical pipes seems like a challenge, since the bottom pipe requires the solder to wick up into the fitting. Just clean the pipe, apply the flux and solder the top pipe to the fitting first, then the bottom. The solder will wick up into the fitting easily and make a waterproof joint.
• Use a heat shield when sweating pipe near flammable materials such as wood or plastic pipe. Wear safety glasses to protect your eyes and leather gloves to protect your hands.

References

• Plumbing 1-2-3; The Home Depot; 2001

Resources

• How to Solder Copper Pipe video