Welding by the shadow. by Rob. (NYC). To run nice and straight stringers with 7018. on pipe, I use what's called  welding by the. shadow. The second pass casts a shadow. exactly at the highest part of the first. This. shadow is a perfect straight line!Just run.the puddle edge along the line formed where.NYC). To run nice and straight stringers with 7018. on pipe, I use what's called  welding by the. shadow. The second pass casts a shadow. exactly at the highest part of the first. This. shadow is a perfect straight line! Just run. the puddle edge along the line formed where.
To establish proper visual lead time on a city street, you should be looking at least 15 seconds ahead, which will work out to be at least a block ahead (about 600 feet). On the highway, you should also be looking at least fifteen seconds ahead as well, which works out to be at least one-quarter of a mile ahead.
When driving in fog, reduce your speed and turn on your headlights. Think about how far they can see and how long it will take you to stop. Keep an eye on your speedometer. Studies show that some drivers acclimate themselves to foggy conditions and unconsciously increase their speed over time.