What is the primary consideration during gunning to achieve full thickness?

The primary consideration during gunning to achieve full thickness is to gradually build up the thickness over a small area. This approach is crucial because it allows for better control over the application process, ensuring that the material adheres properly and fills in any gaps or voids. By applying the refractory material in a controlled manner, the work can be conducted systematically, allowing for even and consistent coverage, which is essential for achieving a uniform thickness.

This method helps to mitigate issues such as sagging or inadequate bonding that could arise if too much material is applied at once or if an area is rushed. Gradual buildup allows for the necessary time for the material to set correctly and bond effectively to the substrate. It also ensures appropriate compaction and minimizes air pockets, which can compromise the integrity and effectiveness of the refractory lining.

In contrast, other methods such as working too quickly or using multiple layers without allowing adequate drying time can lead to poor adhesion and structural instability, which ultimately undermines the effectiveness of the lining. Therefore, careful and gradual application is emphasized to ensure durability and performance in the final product.