Using an SMAW rod with a position number 2 in the vertical position may cause what issue?

When using an SMAW (Shielded Metal Arc Welding) rod with a position number 2 in the vertical position, the main issue that can arise is undercut. Position number 2 indicates that the welding will be done in the vertical position, where the molten weld pool is particularly susceptible to gravity.

In vertical welding, if the welding parameters are not carefully controlled, there is a tendency for the molten metal to flow downwards and pull away from the base material, leading to a groove or undercut along the edges of the weld bead. This undercut creates not only a visual imperfection but could also significantly weaken the weld joint, as it removes material from the weld area that is critical for maintaining the integrity and strength of the connection.

Moreover, this complication requires the welder to have a good technique and understanding of how to manipulate the torch angle and welding speed to minimize the likelihood of undercuts while achieving a sound weld. Thus, in vertical position welding with an SMAW rod, managing undercut risk is crucial to ensure a strong and reliable weld.