How to Solder Copper Pipes
There are a few basic tools you will need before you begin. These can be purchased at any hardware or building supply store in your area. First you will need solder, flux, and a torch to heat the pipes. I use Mapp gas instead of propane as it produces a higher heat. You can find propane and Mapp gas soldering kits that come with a 16 ounce canister of gas and the torch attachment. The propane tanks are always blue and the mapp gas canisters are always yellow. The solder comes in different size roles. You want to use a Silver, Lead Free solder for water pipes which is readily available. The flux also comes in different size containers and may be labeled as Soldering Paste. A small brush which can be found next to the flux in the store is also handy to have to apply the flux to the pipes. You will also want to have a deburring tool and either a copper pipe cleaning brush or some steel wool or emery paper to clean the pipes to be soldered. You may also need fittings to connect the pipes together, Fittings come either straight or angled depending on what you need. Also it is a good idea to wear gloves and eye protection when soldering pipes, remember you are dealing with heat and melting solder which may splatter if you are not careful.
The first step is to turn off the water supply to the pipes you are sweating if you haven’t done so already. Next remove any burrs from the ends of the pipes you are connecting. Remove them from the inside and outside of the pipes. A burr can cause all sorts of problems in the future and the little bit of time it takes to remove them is well worth it.
Next I dry fit everything just to be sure it is all the right length and will fit together. Better to find this out before you start sweating the pipes. Now you can disassemble the fitting and using your cleaning brush or emery cloth clean the fittings till they shine. You will want to clean the inside of the female fitting and the outside of the male fitting. The male fitting is the one that slides into the female fitting. This is the most important step in the soldering process.
Now that the cleaning process is complete it is time to solder. First apply your flux to the inside of the female fitting and the outside of the male fitting. The flux will also further clean the pipes and will help draw the solder in between them. Now join the two pieces together till they fit tightly together.
Unroll about 4 to 5 inches of solder, you will be using the role as a handle when you apply it to the pipes. Next light your torch and apply heat to the fitting. I always apply the heat to the bottom of the fitting going back and forth to apply it evenly to both sides. Remember heat raises. When you see the flux starting to spit and bubble on the top of the fitting, touch the solder to the top where the two pipes meet. If the pipes are hot enough the solder will melt and flow into the pipes. You want to be quick here, remove the heat and move the solder all around the sides of the fitting. It will be drawn into the fitting and any excess will form a drip on the bottom. Use a damp cloth to remove the excess drip.
Allow the pipes to cool then slowly turn the water back on to check for leaks. If there are no leaks you are good to go and finished. If there are any leaks, you have to turn the water off and start over. Remove as much water from the pipes as you can, then reheat them to brake the solder. This will take a little time as water slows down the heating process. The most common cause of leaks is not having the pipes clean enough when you start. Either re clean the pipes or if possible use new pipes and be sure they are absolutely clean. Repeat the steps above. Remember practice makes perfect when soldering copper pipes so don’t be discouraged if you don’t get it right the first time.
