How To Solder Copper Pipe

Authors Website: http://www.remodel-house.com/

As an "owner-builder," I have re-piped quite a few properties, and along the way have learned some time-saving (and frustration-saving) procedures. This article will outline the steps for your first "practice" solder joints. Visit our site for photos and more in-depth information.

Tools and Materials

• Type L or M Copper tubing and fittings $10 (for practice)
• Propane torch $25
• Tubing cutter $5
• Lighter $5
• Solder (lead-free!) $3
• Flux (water-based) $3
• Flux brushes $2
• 180 grit cloth-backed sandpaper $5
• Wire brush tool $5
• Shop rags $5
• Half gallon water container $0
• 5 gallon water container $1
• Fire extinguisher $10
• Optional vice
• Optional washing machine hookup hose

Theory

Molten solder "wicks" or is pulled into the joint between the tubing and fitting by the heat of the fittings themselves, and it only sticks to clean, hot copper. Do not try to solder a wet or dirty joint.

Preparation

1. Hold the copper pipe in one hand (or your vise) and use your tubing cutter to trim a 1-foot section of practice pipe. Operate the tubing cutter by progressively tightening its knob after every 2 revolutions. You will feel it loosen as its wheel bites into the pipe.
2. Remove the burrs from the inside of the cut tube with the tubing cutter's deburring tool.
3. Place the cutoff in the vice horizontally. Do not over tighten.
4. Rip sandpaper in 1-inch wide strip. Holding sandpaper ends in each hand, polish the end of the tube, working your way around the tube until the end of the tube is completely clean.
5. Select a fitting. Use your wire tubing brush with a twisting motion to clean the inside of the fitting to a shine.
6. Check that the fitting fits onto the tube end. Remove.
7. Apply a thin coat of flux to both the outside of the cleaned pipe end and the inside of the fitting. Try to keep the flux in the joint area only.
8. Fill your water containers and get the extinguisher ready. Place a shop rag into the small water container.

Soldering

9. Assemble the fitting onto the pipe end. Light the propane torch: just crack open the propane valve slightly until the flame is on, then turn up the heat. Keep the torch relatively upright.
10. Apply heat to the joint. Keep the solder away from the joint for now! The blue tip of the flame should point at the outside of the fitting and the outer section of the flame should wrap around the fitting. Keep the flame moving around the joint so that you evenly distribute the heat.
11. The joint will start to change color and the outer section of the flame will start to burn greenish. At this point, move the flame to the bottom of the joint and test the joint temperature by touching the end of the solder to the top of the joint opposite the flame. (Don't let the flame melt the solder - the hot metal should melt it!). If the solder starts to melt, quickly remove the flame and run your solder around the perimeter of the joint to draw a bead until you see a single drop of solder come off the bottom of the joint. This takes practice!
12. Wring out your wet shop rag and carefully wipe the joint without causing the fitting to move. You really don't want the fitting to move before the joint hardens.
13. Inspect the solder: you want a smooth, shiny bead of solder completely around the line where the tubing fits into the fitting with perhaps a small drip off the bottom. Most first-timers apply way too much solder.

Testing

Well, if it holds water under pressure, you've done a good job. The easiest way to try this without actually hacking your plumbing is to purchase a washing machine hookup hose and a spigot fitting (not the valve). Solder the spigot fitting onto your practice tube on one end and solder an end cap onto the opposite end of your practice tube. Use the washing machine hookup hose to attach your practice assembly to a hose bib outside and test for leaks. I actually do this to test complex pre-made assemblies when repiping a house.

Article provided courtesy of www.remodel-house.com

Copyright 2004, www.remodel-house.com

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