What type of flame should be used when silver soldering?

When silver soldering, a neutral flame is the appropriate choice because it provides a balanced mixture of fuel and oxygen. This type of flame ensures that the heat is applied evenly without introducing excess oxygen or carbon, which could adversely affect the quality of the joint being soldered.

Using a neutral flame prevents oxidation of the metal, which is crucial for maintaining the integrity and appearance of the soldered joint. It also allows the solder to flow properly into the joint, creating a strong bond between the components.

For comparison, a reducing flame contains more fuel than oxygen, which could introduce carbon into the metal and weaken the joint. An oxidizing flame has too much oxygen, which can cause oxidation and damage to the surfaces being joined. Therefore, the neutral flame is best suited for silver soldering to ensure optimal results.