Which statement best describes the effect of chemically treating a surface for painting?

• A. Chemical conversion coatings increase a surface's resistance to corrosion and improve paint bonding to the surface
• B. Chemical conversion coatings remove all corrosion automatically
• C. Chemical conversion coatings change color only
• D. Chemical conversion coatings have no effect on bonding

Answer: (A)

Chemical conversion coatings modify the metal surface at the chemical level to form a protective, adherent layer. This coating reduces active sites for corrosion and acts as a barrier, increasing resistance to corrosion. It also improves paint bonding by tailoring the surface chemistry and energy so the paint wets and adheres more effectively, creating a stronger, longer-lasting coating system.

They don’t automatically remove all existing corrosion, and color changes can occur but aren’t the primary purpose. Plus, there is a real benefit to bonding, not "no effect" on adhesion.