How to Solder Brass Plumbing Fittings
As an alloy of copper and zinc, brass is compatible with copper, and manufacturers produce many common plumbing fittings with the material. Solder adheres as well to brass as it does to copper, so the fittings are usually molded with slip joints so you can solder them to the pipes. It's easy to solder copper plumbing if you do it right but troublesome if you make a mistake, and a common mistake is to solder pipes while water is dribbling through them. If the pipes and fittings are dry, however, you shouldn't have any trouble producing a watertight seal.
1
Prepare the pipe onto which you are going to solder a brass fitting by first turning the water completely off so that none is dripping from the end. If the pipe is installed horizontally and water is pooling inside it, swab it out with a rag.
2
Deburr the end of the pipe with a file if you used a hacksaw to cut it. Clean off oxidation and dirt with 120-grit sandpaper. Proper preparation of the pipe ensures adhesion of the solder.
3
Spread soldering flux on the outside of the pipe and the inside of the brass fitting with a small brush. The brush usually comes with the flux. Slip the fitting onto the pipe and rotate it into the correct orientation.
4
Heat the joint with a propane torch until the flux begins to boil. When it does, it will turn black and begin to smoke. Remove the heat when this happens. Some brass valves require up to five or six times as much heat to melt solder as other fittings, so be sure the flux is smoking from under the joint and not just around the perimeter.
5
Unroll a coil of lead-free solder and touch the tip to the joint as soon as you remove the heat. Move the solder completely around the pipe as it melts and seeps into the joint. Work quickly. The metal stays hot enough to melt solder only for a few seconds.
6
Solder the other joint of the fitting as soon as the solder in the first joint turns dull and solidifies. Let the fitting cool for 10 to 20 minutes before you touch it.
Things You Will Need
- Rag
- File
- 120-grit sandpaper
- Soldering flux
- Propane torch
- Lead-free solder
Tip
- If you're soldering a fitting onto an existing water line, open one or two faucets somewhere in the line to allow steam to escape.
