Which of the following statements best describes fretting corrosion protection between skin and panels?

• A. A form of adhesive tape placed between the surfaces to prevent metal-to-metal contact.
• B. A paint sealant is applied to the entire surface.
• C. A mechanical fastener alone prevents fretting corrosion.
• D. A heat treatment eliminates fretting corrosion.

Answer: (A)

Fretting corrosion happens when two surfaces in contact under load slide a little against each other, wearing away the protective films and creating corrosion sites. The most effective way to prevent this at a skin-to-panel interface is to put a barrier between the two surfaces so they don’t rub directly against one another. An adhesive tape placed between the surfaces serves that purpose: it separates the metal surfaces, absorbs the tiny movements, and stops the metal-to-metal contact that drives fretting. Painting the entire surface doesn’t stop the micro-sliding, and relying on fasteners alone doesn’t prevent the contact and wear. Heat treating the material doesn’t address the ongoing fretting at joints either.