Filler Wire for Welding Copper Pipe to SS Pipe

Welding copper to stainless steel is more common than you would believe. If I were to TIG (GTAW) these two metals together, my choice of a filler metal would be deoxidized copper. Depending on what you were looking for cosmetically, a TIG weld will probably be your best bet if the finished joint needs to look good. Next, if I decided that I was going to MIG (GMAW) weld the copper and stainless together, I would use Silicon Bronze for the filler wire using 100 percent Argon as the shielding gas. The MIG weld in all probability is not going to be as eye appealing as a TIG weld, but a MIG weld can be completed much quicker than a TIG weld. Another consideration would be the thickness of the metals. TIG would be preferable for thinner materials.

Another factor that would determine which method of welding I would use, is if the metals being joined were going to be subjected to any pressure. If the metals were going to be pressurised to any degree, TIG welding will provide a stronger joint when performed correctly. As with any pressurised device, make sure that the person performing the welding has the knowledge, experience, and the certifications. Because of the safety concerns when welding on systems that will be pressurised, this is not a job for the hobbiest...........good luck.