Sweating Copper Pipes

For those preparing to tackle a DIY plumbing job, there's a good chance you're going to be working with copper pipes—in which case cutting and joining them is almost inevitable. "Sweating" a copper pipe is simply the process of joining two copper pipes using solder. So if cascading streams of water aren't something you want to see in your home, pay careful attention to these tips.

What you'll need:

• Appropriate copper pipes and joints for your project
• Hard or soft, lead-free solder (NOTE: Hard solder contains a phosphorous flux already in its composition. This is toxic if ingested—it should not be used for potable water lines)
• Tube reamer
• Combination wire brush
• Rag
• Plumbing flux
• Propane torch

Preparation:

The first key to achieving a watertight bond between your two pipes is careful preparation of the two mating surfaces. After cutting a pipe, use your reamer to remove any burrs from the cut end, followed by your wire brush to clean both mating surfaces and remove any oxidized copper. Use a clean rag to wipe off any grit. The basic principle here is that clean surfaces will bond tightly. 

Assembly:

Apply plumbing flux on the now-abraded surfaces and connect the joint. Move your torch flame around the joint, keeping the flame just touching the surface and heating evenly. The copper should get shiny as the flux proceeds to melt, followed by the metal getting dull and the flux beginning to smoke. This indicates it's time to apply your solder.

Soldering:

Carefully touch the tip of the solder to the joint, keeping the flame on the joint to maintain the temperature. The solder should be sucked directly into the joint as it melts. On horizontal connections, start applying the solder at the bottom of the joint and work your way up and over the pipe, then back around. For vertical pipe connections, apply the solder evenly around the pipe. 

Click here for more information on keeping your newly assembled pipes from freezing during the winter.

Until next time, 

The Home Know-It-All 

Comments

[Bassfeed]

There are some simple, solder-free alternatives that are worth considering. Crimped fittings and friction fittings are becoming widely available at big box home stores.

But if you must solder, consider using pre-soldered fittings. Also readily available.