Introduction: How to Sweat Copper Pipe - DIY Guy

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Sweating (or soldering) copper pipe isn't as difficult as you might think. It just takes the right tools and a little know-how.

Step 1: Watch the Video

It's less than two minutes long, no sweat.

See what I did there? Of course you do.

Step 2: Gather Your Materials

Step 3: Sand the Pipe

Use some of the open mesh cloth to sand the cut ends of the pipe.

Copper oxidizes naturally, so make sure to sand down to bright, shiny copper.

Wipe the copper with a clean towel to remove any excess debris.

Step 4: Sand the Fittings Too

You'll also want to sand the inside of the fitting. That's what's going to make contact with the pipe.

Step 5: Time to Flux

Apply a thin layer of flux to the outside of the pipe, and the inside of the fitting.

Flux reacts with the copper and heat and helps ensure you have a clean solder joint.

Step 6: Assemble the Joint

Go ahead and put the pieces together.

If you have more than one joint to make, you should probably avoid trying to do them all at once. Plan ahead and take them one at a time.

Start with your lowest joint, because heat rises. Your later joints will take less time to heat up.

Step 7: Heat and Solder

The idea with this kind of soldering is to apply heat to the joint, not the pipe. And definitely not the solder.

That way, when you apply the solder, the heat inside the joint will suck the solder in. Science!

That's really all there is to it.

Heat + Solder + Capillary Action = Molten Metal sealing a joint.

Step 8: Wipe the Joint Down

Let the joint cool off enough for the solder to set up. This doesn't take long.

Get a (damp) wet rag and carefully wipe down the joint.

You'll get a bit of steam as the joint cools, and that's pretty neat looking, but this is really to remove excess flux from the joint. Flux left on the pipe is what causes oxidation years down the road.

And if that happens, you're back where you started, with a leaky pipe.

That's it, you're done! Move on to the next joint and repeat.

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