What is typically used to fill in gaps before applying final fabric coverings?

Filler compound is typically used to fill in gaps before applying the final fabric coverings on aircraft structures. This specialized material is designed to create a smooth and even surface, ensuring that the fabric adheres properly and uniformly. Utilizing a filler compound helps to eliminate any irregularities or imperfections, which is critical for achieving the proper aesthetic and structural integrity in the finished aircraft fabric covering.

When gaps are left unfilled, they can lead to issues such as poor adhesion of the fabric, potential air pockets, or areas where moisture can accumulate, which can compromise the overall durability and safety of the covering. The use of filler compound is an essential step in the preparation process, allowing for optimal adhesion of the fabric and enhancing the longevity of the covering system.

Other materials like fabric tape, sand, or adhesive serve different purposes in the fabric covering process, such as reinforcement or bonding, but they do not specifically address the need to fill gaps in the structure in the same way that a filler compound does. Filler compounds are formulated to work well with the materials involved in the fabric covering process and are crucial for facilitating a smooth finish before the final application of fabric.