What type of flame should the torch be adjusted to during silver brazing?

The ideal flame type for silver brazing is a neutral flame. A neutral flame occurs when the acetylene and oxygen are mixed in equal parts, resulting in a balanced combustion that produces a clear inner cone and a defined outer envelope.

This flame provides the optimal temperature for melting the brazing filler metal without affecting the base metals. It ensures that there is no excess carbon or oxygen in the flame that could lead to oxidation or improper bonding during the brazing process.

Other flame types, such as oxidizing or carburizing flames, could introduce issues. An oxidizing flame has excess oxygen, which can lead to oxidation of the metals being joined, negatively impacting the strength and integrity of the brazed joint. A carburizing flame, which has excess acetylene, can introduce carbon into the metal surfaces, potentially leading to weakening or contamination.

Thus, adjusting the torch to a neutral flame when silver brazing is essential for achieving strong, clean joints and maintaining the quality of the materials involved.