Soldering Copper Pipe... It's As Easy As It Looks!!
by Scott Gray of EverydayHandyman.com
Successfully soldering copper water pipe depends in large part upon proper preparation of the surfaces involved. Just like the old carpentry adage, "Measure twice, cut once", learning how to successfully solder copper water pipe is often a matter of "Clean twice, solder once."
Proper safety precautions are vital. Accidents always happen to the other guy... until they happen to you. You'll need safety goggles, flame protector cloth or metal flashing, flame resistant leather gloves to protect your hands, and a heavy shirt to protect your skin from anything that might drip down or fall on you while you are working.
It doesn't take much heat to ignite old, dry wood and many fires are caused every year by the improper use of propane torches. Always keep a bucket of water and a home fire extinguisher nearby when working with a propane torch! If you may need to turn off the water main, having a few additional buckets of water handy is an especially good idea!
Assemble Your Materials
The materials you'll need to solder copper water pipe include:
- A propane torch, preferably with a self-igniting regulator (don't try to light a torch with matches).
- A copper pipe/tube cutter large enough for the job.
- Lead-free solder.
- Flux (also called 'tinning flux' or 'paste flux') to clean and prepare the joints to accept the solder as the copper pipe heats.
- 120-grit emery cloth or 120-grit sandpaper to smooth and clean the joints.
- A small fitting brush (for cleaning inside the joints).
The Soldering Process
Once you've assembled all your safety items and your soldering materials, the next step is to thoroughly clean and dry the copper pipes you are about to solder. Careful preparation is such a big part of soldering because it will save you time and effort. Prepare all the joints you need to solder at once, and then solder all of them one by one, in a single sitting.
- Cover any flammable surfaces with the fireproof cloth or a piece of sheet metal, and set your bucket or water and fire extinguisher nearby.
- Copper pipes will not accept solder if any moisture is left in them. One good way to bleed all the water out of an existing copper pipe is to leave an end open (such as the sink drain) and heat the pipe with the tip of the flame to speed evaporation.
- If you are cutting new copper pipe and then soldering it, hold one end of the pipe under your knee and the other with your free hand as you slowly twist the pipe cutter. If you twist the cutter too fast, the pipe will collapse, so go slow taking small cuts at a time.
- Thoroughly clean the ends of the copper pipe you will be soldering. Even though it make look as though the cut is very clean, you still need to smooth it with the emery cloth, and smooth the inside with the pipe brush or the cloth wrapped around your finger. The more thoroughly you clean, the higher your success rate.
- Cover the surfaces to be soldered with flux.
- Fire up your soldering torch, and hold it so that the tip of the cone of fire hits the fitting. The hottest part of the cone is the tip, and copper conducts heat so well that you only need to touch the fitting, not the pipe itself. Hold the solder wire opposite the flame at the coolest point.
- When the temperature of the copper pipe hits the melting point of the solder you are hold against it, the solder will turn into liquid flow into the joint naturally. Fill the joint until the solder drips out before moving on to the next joint.
- Do not touch the soldered joint for 45 seconds minimum after soldering.
- Always turn off your soldering gun before setting it down.
Some general tips to keep in mind while learning how to solder copper water pipe:
- Remember to remove all soft rubber or plastic parts before soldering any plumbing joint. For example, disassemble shutoff valves before soldering so you don't damage the washers and o-rings.
- If a copper tube is larger than 3/4" inch wide, it can help to heat it from several angles with the torch to get the solder to melt evenly.
- Brass fittings require more heat and you will have to take care not to leave a valve open so pressure doesn't build in the tube and cause damage.
Once you've gotten the technique down, soldering copper water pipe is not as hard as it looks. It's a worthwhile skill to learn, and one that can save you big money on plumbing bills for small repairs and kitchen and bath projects.
About the author: Scott Gray is a handyman enthusiast and web publisher. He enjoys providing tips to consumers and homeowners at his website Everyday Handyman.