Where should the arc be restarted or struck on a previously unfinished bead?

Where should the arc be restarted or struck on a previously unfinished bead?

• A. About 3/8" (10mm) in front of the forward edge of the crater
• B. In the middle of the previous crater
• C. At the trailing edge of the previous bead
• D. All of the above are acceptable

Answer: (A)

When re-starting an arc on a bead that isn’t finished, you want the new arc to land just ahead of the end of the previous bead. Striking about 3/8 inch (10 mm) in front of the forward edge of the crater lets the heat and fusion flow into the existing weld and begins a new bead that properly ties into the previous pass. This position helps avoid creating a weak interface at the rear of the bead or leaving a crater crack, and it promotes a smooth, continuous weld as you weld forward. Restarting in the middle of the crater or at the trailing edge tends to produce bad fusion, gaps, or cracks, so those locations are not acceptable. Hence, the best restart point is a short distance in front of the crater.

When re-starting an arc on a bead that isn’t finished, you want the new arc to land just ahead of the end of the previous bead. Striking about 3/8 inch (10 mm) in front of the forward edge of the crater lets the heat and fusion flow into the existing weld and begins a new bead that properly ties into the previous pass. This position helps avoid creating a weak interface at the rear of the bead or leaving a crater crack, and it promotes a smooth, continuous weld as you weld forward. Restarting in the middle of the crater or at the trailing edge tends to produce bad fusion, gaps, or cracks, so those locations are not acceptable. Hence, the best restart point is a short distance in front of the crater.