How to Sweat Copper Pipe - DIY Guy

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

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

See what I did there? Of course you do.

You'll need your copper pipe and fittings. We'll assume you've already got these cut and ready to join.

Here's what else we used:

BernzOmatic Map-Pro Hand Torch Cylinder

BernzOmatic Trigger-Start Head Handheld Head

Worthington 16-oz Lead-Free Copper Pipe Solder

Worthington Open Mesh Sand Cloth

RectorSeal 1.7-fl oz Nokorode Soldering Flux

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.

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

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.

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.

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.

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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