Why is cleaning metal surfaces important before brazing?

Cleaning metal surfaces before brazing is crucial because contaminants such as dirt, oil, oxidation, and other debris can interfere with the brazing process. These unwanted materials can prevent proper adhesion of the filler metal to the base metals, leading to a weak joint. When the joint does not bond correctly, it can result in voids, reduced strength, and even joint failure under stress.

By ensuring that the metal surfaces are clean, you promote a strong and effective bond, enabling the filler material to flow into the joint properly and create a reliable connection between the pieces being joined. This practice is essential for achieving the integrity and durability required in brazed joints, particularly in applications where strength and reliability are vital.