Solder a Simple Copper Connection

The cottage renovation is in full swing. We're starting at the bottom and working our way up. That means that we needed to replace a few pipes in the basement that were old galvanized steel and deteriorated to the point that it was reducing the water pressure.

Mostly, I was using PEX with copper crimp rings and barb fittings, however, there were a couple copper connections needed near the water heater. (You're not supposed to use any plastic pipe, such as PEX or CPVC within 18" of the water heater.) Anyway, I thought I'd share the simple process for a solder joint when working with copper.

To get started you might pick up a basic soldering pack at the hardware store. It might contain a small propane torch, solder, flux, and flux brush.

1. Cleanly cut the copper pipe. It's best to use a pipe cutter meant for this purpose because you'll get a square cut. It's much more difficult with a hacksaw.

2. Clean the pipe. I've got a helpful little tool with steel brushes for both 1/2" and 3/4" pipe. A small piece of sandpaper can also do the job. You want to scrub the pipe until the copper is shiny. Family Handyman, in this article about soldering copper, calls cleaning the pipe "the A-1 key to copper soldering success". Don't skip this step. (By the way, you can even reuse old copper pipes if you clean it properly to make a good connection.)

3. Brush some flux on the areas to be soldered, both the end of the pipe and the inside of the fitting. Flux is a chemical composition that helps clean the copper to prepare it for solder and it also helps in the heat transfer.

4. Heat the fitting with a propane torch. Notice I said to heat the fitting. This is important. Specifically, you want to apply the heat to the female end of the fitting that's receiving the pipe. The flux helps the heat to also heat up the pipe inside. Move the flame back-and-forth across the fitting to heat it evenly.

5. Hold the solder on the joint in a spot opposite the flame. This is the coldest part and you want it to be hot enough to accept the solder. When the fitting is hot enough it will just 'suck' the solder in and you're done. Enough solder should be taken in that it drips out the bottom of the fitting, but there's no need to overdo it. The heat will do the work.

6. Let the pipe cool. It will stay hot for a while. In my case, I later attached some 1/2" PEX to the barb on this fitting using copper rings with a PEX crimp tool... but, that's a lesson for another day...

-Peter

www.CarpentryGuy.com