When joining copper to copper, you would use which material?

When joining copper to copper, you would use which material?

• A. Solder
• B. Brazing alloy
• C. Flux
• D. Welding rod

Answer: (B)

Joining copper to copper uses a brazing alloy as the filler metal. In brazing, the tube pieces are heated until the brazing metal melts and flows into the joint by capillary action, bonding the copper as it cools. Flux is used to clean the surfaces and promote wetting, but the actual joint strength comes from the brazing alloy itself. This creates a strong, leak-tight connection suitable for HVAC pressures and temperatures. Solder melts at too low a temperature and generally lacks the strength for HVAC service; welding would fuse and potentially distort the copper tubing, which is undesirable for small refrigerant lines.

Joining copper to copper uses a brazing alloy as the filler metal. In brazing, the tube pieces are heated until the brazing metal melts and flows into the joint by capillary action, bonding the copper as it cools. Flux is used to clean the surfaces and promote wetting, but the actual joint strength comes from the brazing alloy itself. This creates a strong, leak-tight connection suitable for HVAC pressures and temperatures. Solder melts at too low a temperature and generally lacks the strength for HVAC service; welding would fuse and potentially distort the copper tubing, which is undesirable for small refrigerant lines.