Aircraft Covering When dope-proofing the parts of the aircraft structure that come in contact with doped fabric, which of the following provide an acceptable protective coating? 1. Aluminum foil. 2. Resin impregnated cloth tape. 3. Any one-part type metal primer. 4. Cellulose tape. a. 1 and 2. b. 3 and 4. c. 1 and 4.