Explain how to use a hot pass to clean out trapped slag.

Question

What will be an ideal response?

Answer 1

The fastest way to clean out trapped slag and make the root pass more uniform is to use a hot pass. The hot pass uses a higher-than-normal amperage setting and a fast travel rate to reshape the bead and burn out trapped slag. After chipping and wire brushing the root pass to remove all the slag possible, a welder is ready to make the hot pass. The ideal way to apply a hot pass is to rapidly melt a large surface area so that the trapped slag can float to the surface. The slag, mostly silicon dioxide (SiO2), may not melt itself so the surrounding steel must be melted to enable it to float free.