How to Weld Stainless Steel and Copper

The welding of stainless steel and copper is often necessary when high-performance joints are required in plumbing. A process called brazing is used to weld copper and stainless steel together. Brazing is a lot like the soldering process. A filler metal is heated until it begins to melt. The filler metal joins the two pieces together. Brazing uses a higher heat than soldering does, requiring 842 degrees Fahrenheit to melt the filler metal. A torch is used to create the necessary heat.

Brazing of stainless steel and copper may be necessary in the kitchen, or on beer brewing equipment.
  1. Clean the two pieces of metal being joined using a steel wool pad.

  2. Mix borax flux powder with water to make a paste. Brush the borax flux mixture onto the joint using a flux brush.

  3. Light the pilot light for your brazing torch using the instructions included with the tool.

  4. Place the two pieces of metal on a firebrick. The firebrick allows the entire metal piece to heat up.

  5. Put on welding glasses and turn on the compressor for your welding gun. Turn the gas control knob to the on position to light the torch.

  6. Apply heat evenly to the two pieces of metal along the joint with the borax powder on it. Apply the heat until the joint begins to glow red.

  7. Touch the end of a brazing rod to the red joint, holding the flame to the joint. Push the rod gently against the hot area until it melts. Drag the rod against the joint until all of it is filled.