*3.4.4 Overhead position*

The overhead welding position is the most difficult, even for the most skilled tradesman. **Figure 9** illustrates some of the challenges posed by the gravitational vector in executing an overhead weld. In the overhead position, the weld pool wants to naturally flow in the opposite direction of the joint. This will cause weld material to sag away from the joint as it cools, creating a crown [12]. A crown is an excess concavity of the face of the weld material that sags away from the joint [13]. Poor

overhead welds can have void spaces, so keeping the arc tight and the diameter of the weld pool small helps avoid this defect. Welding in the overhead position is generally avoided if possible, but if required, additional care must be taken to identify problems and correct deficiencies. A project manager must understand that this weld is extremely challenging and to be approached with caution in a repair.
