How should the initial gunning operations be conducted?

Starting the initial gunning operations from the lowest elevation and working up is the recommended practice for several reasons. This technique allows for better control of the placement and density of the refractory material. When gunning from a lower point and moving upwards, it minimizes the risk of the material sliding down or falling off, which can occur if you start at a higher elevation.

Additionally, beginning at lower elevations allows the operator to effectively manage the application and ensure that the material has adequate bonding and adherence as it builds upon itself. The upward movement ensures that the material can have time to cure and set properly, especially under certain environmental conditions.

This method also helps in achieving better compaction of the material and avoids potential voids which could lead to performance issues later on. Overall, this approach leads to a more uniform application, which is crucial for the integrity of the refractory lining.