How to Solder Copper Pipe

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How to Solder Copper Pipe

Copper tubing or pipes work well for air, water or even refrigerants. If you want to join them together with “sweat joints”, you’ll have to learn how to solder them properly. It can be tricky, but if done good, will yield positive results. Here’s how to solder copper pipes.

What You’ll Need:

  • Copper pipes
  • Propane torch
  • Solder
  • Flux
  • Safety goggles and gloves
  • Sandpaper
  • Copper tubing cutter
  • Wire brush
  • Emory cloth


  1. If you’re making repairs to existing copper pipes installed in your home already, make sure to shut the water supply off before you begin, and you drain the line as much as possible. Water can cause problems when you start soldering.
  2. Measure the copper pipe you’re going to need for the task. Make sure you account for additional space for the junctions and elbows before you cut. Use the tubing cutter for this.
  3. You have to clean and dry the copper pipes that will be soldered. Use a wire brush to clean the pipe and fitting, both inside and out, to remove skin oils and burrs. You can also use an emory cloth to sand the pipe.
  4. Get the flux and brush a light coating on the pipe and the fitting. Flux allows the solder to flow in the joint properly, so it’s very important.
  5. Using the propane torch, heat the fitting and the pipe. Make sure you don’t contact other surfaces, though. Use the middle flame, aiming it at the sections to be soldered. Move the flame around, so the heat will not be focused on just one area. When the flame gets a green glow, meaning you’re ready to apply the solder.
  6. Touch the end of the solder to the joint, and it will flow properly. If it does not, remove the solder, and heat the parts again. There’s no need to have the flame touch the solder; the hot metal is enough.
  7. When you’ve given enough heat, the solder will flow well. Take away the propane torch and push in at least two inches of solder, so you can move it all the way and it will cover the whole circumference.
  8. Let the joint cool before you begin cleaning up. When it’s cool enough to be touched, use steel wool to clear carbon deposits. You’ll see if there are possible leak holes.

Some Tips:

  • Only turn on the water supply when you’re completely done.
  • When working with the torch, make sure you have a way of putting out flames near you, in case an accident happens.
  • Wear gloves and eye protection while soldering. Flux is a very toxic substance.

Copper pipes are very handy, but soldering them the right way has a large effect on their efficiency. Follow these steps and be able to do copper pipe soldering all by yourself.



  1. Dale said,

    on October 28th, 2009 at 9:44 am

    How old can copper pipes be in a house before they sre to old to use?