What are the two types of dope used for fabric finishes?

• A. Cellulose Nitrate and Cellulose Acetate Butyrate
• B. Nylon and Polyester
• C. Epoxy and Polyurethane
• D. Acrylic and Vinyl

Answer: (A)

In fabric-covered aircraft, the dope used to tighten and seal the fabric finishes comes from two main chemistries: nitrocellulose (cellulose nitrate) and cellulose acetate butyrate. Nitrocellulose dope tightens the fabric as it dries, creating a stiff, weatherproof skin and delivering a strong, durable film quickly. Cellulose acetate butyrate dope provides a smoother, more flexible finish with lower flammability and greater resistance to cracking, making it useful on fabrics where less shrinkage or more elasticity is desired. Together, these two dopes represent the classic options for fabric finishes. The other resins listed are used in different coatings or materials, but they are not the traditional fabric-doping chemistries used to tighten and seal aircraft fabric finishes.