Training Video: Drilling Zone 3
This 8-minute video provides a brief overview of drilling through zone 3, hard layers. A hard layer is defined as any layer in which the 6" auger or 5" auger will not work. When you encounter a hard layer your first option is a 4" auger. One geological zone where it would be appropriate to use the 4" auger or 3"or 5" stubber is hard-pack clay.