We have been talking about bathroom remodeling and I thought it would be a perfect time to talk about this. I think one of the big hesitations or fears in redoing your bathroom is getting leaks in the plumbing. Water leaks always create such a mess. So this fear is a good and real one. BUT it doesn’t need to be.

There are a lot of things to learn or know about plumbing that takes years to learn but this is not one of them. Your water supply water flows up down sideways, all just as easy as the other, so you don’t have to worry about how many fittings you have but you do need to solder them together correctly in order for them not to leak.

So here is how you do it but first some safety information and tips:
1. Always wear eye protection and gloves when soldering and when working with flux. Flux is a toxic acidic substance and the pipes get very hot.
2. Note: Because you are working with a flame, often in a confined space, be aware of flammable materials near where you are working. You may even need to set up a non-flammable heat shield between the solder joint and flammable material nearby. Keep a fire extinguisher handy.
3. Take appropriate steps to shut off the water supply to the area you are working on if that is possible, or to the entire house. Make sure the pipes are completely dry or it will interfere with your ability to heat the pipes properly and for the solder to bond properly. Note: If you cannot completely stop the flow of water from the pipe you are working on, it may be impossible to heat the pipe hot enough. Take a wad of white bread (without the crust) and stuff it into the pipe. This will hold the water back for a minute or two. After that the bread will dissolve harmlessly in the pipe and is easily flushed out.
4. Check with your local authority for applicable codes about the work you wish to perform and the necessity of permits before you begin your project.

Soldering pipes is easy once you get the hang of it. When copper pipes are put together, there is a very small gap between the fitting and the piece of pipe. When the pipes are heated, and solder is touched to the pipes, the solder melts and is drawn up into the gap through capillary action. When the gap is filled, and the pipes are allowed to cool, the solder welds the pipes together and this makes a watertight joint.

The key is to recognize that you are heating the pipes, not the solder. The heated copper piping melts the solder. By following the steps in this article you should be able to make watertight joints. You may want to practice on some spare pieces until you feel confident.

1. Cutting your pieces of copper using a tube cutter is best, but cutting it with a hack saw is possible but either can leave burrs. Remove all burrs from the inside and outside edges of the pipe with a deburring tool. Small burrs can cause the pipes to not fit together properly and can result in a variety of problems in the lifespan of the water supply system.
2. Clean the outside of the pipe and the inside of the fittings with a copper pipe cleaning brush, or simply use steel wool or emery cloth. This removes oxidation and should give it a brilliant shine. This is necessary for the solder to bond to the pipe properly and if not done may cause a leaky joint.
3. Apply acid-free flux to both the outside of the pipe and the inside of the fittings. Flux cleans the copper a little more plus helps to prevent oxidation as the pipe is heated. Oxidization may cause the joint to leak.
4. I prefer to fit all the pipes together before you start to solder the pieces together. In some cases though you may want to solder a few pieces together first but you have to make sure they stay positioned correctly so they fit together right.
5. Unroll a few inches of solder (always use only lead-free solder) and straighten it out. Sometime I put a little hook on the end so I can fit it behind and around the pipe. You can use the roll as a handle to hang onto it when applying the solder.
6. With your torch apply the flame to the joint. (Your torch often is a small propane tank with a torch head on it though there are many types of torches you can buy or rent to do the job). Move the flame around to ensure that you’re heating the pipe completely all the way around even on the opposite side from you.
7. When the flux begins to bubble and spit, touch the tip of the solder to the joint. The solder should melt and disappear into the joint. Move the tip of the solder wire around the entire joint to ensure that solder fills in all the way around. Remove the heat and the pipe’s temperature will drop quickly and the solder will become solid. If the joint stopped taking up solder in the process because the solder was not melting, before the joint was complete, then quickly add more heat so that more solder can be applied.
8. Be careful not to overheat the copper pipes as this will cause them to oxidize and this will prevent the solder from bonding properly.
9. You know the joint has enough solder when it will build up outside of the joint and begin to drip. You can use a damp rag to wipe off the excess solder and clean the joint.
10. When you have finished soldering and the pipes have cooled (only a couple of minutes) always turn the water on and check for leaks.
11. If the joint leaks, you must open the joint, remove all the solder and start over by cleaning the metal and applying flux. It may be easier to start over with new fittings.

Again soldering copper pipes is easy once you get the hang of it. You can do it with a little practice. Main tips: Have dry pipes. Clean them properly. Flux them well. Heat the pipes not the solder. Don’t overheat them.

Have Fun!

Posted by Dave McIntosh on Sunday, March 8th, 2009 at 6:00 pm.