How To Solder Copper Piping

The world of plumbing continues to change and evolve just as technology seemingly alters everything in our lives. Due to its resistance of rusting, water supply lines inside the home were galvanized pipe and the sewer system was cast iron pipes.

Today PVC, CPVC and varied roll tubing constitutes the majority of newly installed water supply lines, with PVC & CPVC used for the sewer system. These new products are much easier and faster to install, which saves the builder construction time and ultimately the consumer money.

This is all great, but what about the current million(s) homes which currently have water supply lines made of copper. What happens when a water line freezes and breaks, replace the entire water supply line? Of course not, that would be cost prohibitive, you repair the copper line at the break.

I’m going to guide you through a simple repair of a ½” copper water line which supplies the kitchen sink with cold water, by showing you how to solder in a repair coupling permanently sealing the leak.

Naturally, the first thing you do is shut the water supply off to the pipe which is broken to stop anymore damage from occurring. A wet or cluttered work area only complicates matters, so clean and dry the area before starting the repair work.

You’ll have to analyze the size and length of the split pipe in order to decide how much of the pipe you’re going to cut out. If there’s only a pin hole leak, you can get away with cutting the pin hole out and replacing it with 1 repair coupling. If the split is ¼” or bigger, you’ll have to cut out more piping and use two repair couplings.

I suggest if the pipe has frozen and split, always use 2 repair couplings and new pipe. The reason being, copper pipe can actually swell, becoming thicker walled, before actually splitting. If you cut the pin hole out, there’s a possibility the repair coupling will not fit over the copper pipe because it had swelled at that point.

Let’s assume we cut 3″ out of the copper piping, which we’ll now have to replace before the water can be hooked back up. Here’s a list of materials and tools required to perform this repair.

* Copper Pipe ½”, it comes in 10′ lengths, but most home repair stores such as Home Depot and Lowes sell shorter lengths, although it may not be much more expensive to buy the entire stick and have remaining pipe for another job. If you can’t transport a 10′ piece they will cut in halve.

* Solder, Flux, sandpaper (fine), a propane torch and Inside pipe cleaner brush. You can sandpaper the inside, but the brush is better and cheap.

* 2 – ½” repair couplings. It’s important to get repair couplings and not regular couplings. Regular couplings have indentations on the inside of the fitting which only allows the pipe to be inserted half way into it, in order to provide an ample amount of soldering area. The repair couplings do not have this making it to where you can slide the fitting up and down the pipe.

This is essential to be able to install the repair section into an situation where there is no play (movement) of either of the stationary pipes being repaired.

* A rag, for wiping excess solder off the fitting and a glass or pan of water handy in case you catch something on fire you didn’t mean to.

The repair procedure is as follows.

* Measure the gap of the cut out section and cut a piece of pipe slightly shorter. There are exact formulas for figuring the length, but in your case, close is plenty good enough. So for a 3″ opening, cut a 2 ¾” piece of pipe allowing you an 1/8″ clearance on either side.

** A rule. Copper pipe and fittings must be 100% clean. Clean to a bright shiny gloss at least 2″ down the pipe. After cleaning do not touch the cleaned end with your fingers, as the oil from your skin can compromise the joint and create a leak. Always use plenty of flux.

* Take a piece of sandpaper and clean both ends of the existing pipe. Polish to a very bright shine. * Use the brush included in the flux container and smear the flux completely around the pipes.

* Wire brush the inside of the two couplings, apply flux and slide one on each pipe end. Sand and apply flux to the 2 ¾” pipe and insert into the gap, moving the repair coupling(s) as needed to insert the piece. Make sure the couplings are positioned to cover both ends of the pipe evenly. Your work is now perfectly aligned, cleaned, fluxed and ready to solder into a solid pipe.

* Propane torch instruction. Light the torch with a striker or a match. Adjust the flame to where the light blue flame inside the main flame ends in a sharp point, that’s your hottest flame. When applying the heat to the pipe, do not engulf the pipe in the flame, just the end of the flame is required.

* Solder instruction. Solder comes in a roll which you hold in your hand. Unroll a 8″ to a foot of solder, bend a ½” of the end of the solder at a right angle. The foot of solder is to extend your reach to the solder joints, but only ½” of solder is required for a ½” pipe joint. A little more is ok, but not too excessive as too much does nothing but run down the pipe or drop onto the floor.

* You will solder one coupling at a time. The first coupling will take a little longer than the first because you’ll need to warm the pipe, the heat transfer will warm the second joint.

* Move the torch flame back and forth across the coupling joints evenly heating it. You’ll hear the flux begin to sizzle and it will solidify. Touch the solder to the joint, if the pipe is not hot enough the solder will do nothing, but if the pipe is hot enough the solder will melt and quickly seal the joint. There is no need to move the solder around the pipe, the solder will automatically encircle the pipe closing the seam.

* Repeat for the other coupling, but it will probably melt the solder immediately.

* Wipe any excess solder from the joints with a rag, do this before it cools.

Allow the repair a minute or so to completely set up, then slowly turn the water back on, checking for leaks.

You’ve repaired a broken copper water line, costing about $30 to $40 bucks versus calling a plumber and paying $400.