What could happen if too much flux is applied when sweating copper?

Bubbles forming during sweating copper joints can occur when excess flux is applied due to the way flux interacts with moisture and contaminants. When too much flux is present, it can create an environment where trapped air or moisture beneath the liquid flux can expand and form bubbles upon heating. This not only disrupts the flow of solder but can also result in poor joint integrity.

In the context of soldering, flux is essential for cleaning the metals and preventing oxidation, but its application must be controlled. Using too much flux does not enhance the process; instead, it can lead to complications such as uneven heating and insufficient bonding between the metal surfaces. Therefore, managing the amount of flux is crucial for achieving a strong, reliable joint when sweating copper.