Coating the Fabric

Coating the Fabric

• Is defined as sealer coat in most the fabric covering processes is applied after all finishing tapes have been installed unless it was applied prior to rib lacing as in a dope-based finishing process. This coat saturates and completely surrounds the fibers in the polyester fabric, forming a barrier that keeps water and contaminants from reaching the fabric during its life.
• It is also used to provide adhesion of subsequent coatings. Usually brushed on in a cross coat application for thorough penetration, two coats of sealer are commonly used but processes vary on how many coats and whether spray coating is permitted.
• With the sealer coats installed and dried, the next step provides protection from UV light, the only significant cause of deterioration of polyester fabric. Designed to prevent UV light from reaching the fabric and extend the life of the fabric indefinitely, these coating products, or fill coats, contain aluminum solids premixed into them that block the UV rays.
•  They are sprayed on in the number of cross coats as specified in the manufacturer’s STC or AC 43.13-1 instruction under which work is done. Two to four-cross coats is common. Note that some processes may require coats of clear butyrate before the blocking formula is applied.
•  Fabric primer is a coating used in some approved covering processes that combine the sealer and fill coatings into one. Applied to fabric, after the finishing tapes are installed, these fabric primers surround and seal the fabric fibers, provide good adhesion for all of the following coatings, and contain UV blocking agents.
•  One modern primer contains carbon solids and others use chemicals that work similarly to sunblock for human skin. Typically, two to four coats of fabric primer are sufficient before the top coatings of the final finish are applied.