Back-step welding technique

When backstep or block welding, you divide the long weld into short sections and don't weld them in sequence, but skip sections or work in the opposite direction. The point is to prevent heat from building up in one spot and to reduce distortion. Let each section cool briefly before starting the next. Make sure to overlap the sections cleanly and distribute heat evenly across the part, otherwise you'll get cold laps or uneven distortion.