Certified Welding Inspector Practice Exam

What describes an acetylene feather?

1. A bright blue flame produced by acetylene

2. A smooth, uniform edge of a weld

3. The intense white edge adjacent to a carbonizing flame

4. A byproduct of combusted acetylene

The correct answer is: The intense white edge adjacent to a carbonizing flame

An acetylene feather refers to the intense white edge that is visible adjacent to a carbonizing flame during the welding process. This phenomenon occurs in oxy-acetylene welding, where the flame can have different characteristics depending on the ratio of oxygen to acetylene. A carbonizing flame has an excess of acetylene, which results in a luminous outer envelope that is typically white in color, leading to the term "feather." The visibility of this white edge is significant because it can indicate the presence of chemically reducing conditions, which may affect the appearance and quality of the weld. Understanding this aspect of the flame characteristics is crucial for welders, as it helps in achieving the desired welding effects and ensuring the integrity of the welded joint. The recognition of the acetylene feather assists in fine-tuning the flame settings for optimal welding performance.