When brazing horizontal joints, where should filler metal be applied?

When brazing horizontal joints, applying the filler metal off center at the bottom of the fitting is appropriate. This technique takes advantage of gravity, allowing the molten filler metal to flow into the joint more effectively from the bottom as it fills any gaps or spaces between the pieces being joined.

The rationale is that when the filler metal is applied at the bottom, it will naturally rise through capillary action to fill the joint, ensuring that the entire area is adequately filled without leaving voids. This method also aids in achieving a stronger bond because it allows the molten metal to properly penetrate the joint, creating a more reliable and durable connection.

In contrast, applying the filler metal at the center or the top of the fitting may not facilitate optimal flow and could result in an incomplete joint or weaker bond. Applying it all around the joint can be wasteful and unnecessary, especially when the lower approach is effective, as it can lead to excess filler metal being used or misplaced. Therefore, applying the filler metal off center at the bottom is the most effective strategy for horizontal joints.