How should a structure that will be covered with doped fabric be prepared following inspection and prior to covering?

• A. Sanded and cleaned with solvent.
• B. Soaked in paint.
• C. Removed all coatings and left bare.
• D. Treat it with a protective coating of paint or varnish as appropriate.

Answer: (D)

Before you apply the fabric, the surface needs to be sealed and protected so the dope and fabric bond properly and moisture can’t soak into the substrate. After inspection, treat the structure with a protective coating of paint or varnish as appropriate. This coating provides a smooth, sealed base, helps resist moisture, and creates a consistent surface for the fabric and subsequent dope. Cleaning or sanding alone won’t prevent moisture entry or ensure even bonding, and leaving the surface bare invites deterioration and poor adhesion. So applying the appropriate protective coating is the correct preparation step.