Which type of refractory is suitable for filling cracks in monolithic refractory?

The appropriate choice for filling cracks in monolithic refractory is gunnable refractory. This type of refractory material is specifically designed to be applied in a plastic or fluid-like state, allowing it to be easily pushed or gunned into tight spaces, such as cracks or gaps.

Gunnable refractories have the right consistency and adhesive properties that facilitate good bonding to existing monolithic materials, ensuring that the repaired area maintains structural integrity and withstands high temperatures. This property is critical in applications where thermal stability and durability are required, such as in furnaces or kilns.

In contrast, brick refractory is more rigid and designed for specific shapes. Castable refractory, while also able to be formed, is typically used to create shapes or structures rather than for repairing cracks. Insulation refractory is specifically formulated to provide thermal insulation and would not be ideal for repairing structural damage, as its primary purpose is not to bond with or fill gaps in other textures.