Which sequence describes how magnesium engine parts should be cleaned?

• A. Wash with a commercial solvent, decarbonize, and scrape or grit blast
• B. Soak in water, scrub with steel wool, air dry
• C. Sandblast, wash with solvent, then paint
• D. Ultrasonic clean with water only

Answer: (A)

Magnesium engine parts must be cleaned in a way that removes all oils, carbon deposits, and surface contaminants without leaving moisture that can attack the metal. Start with a commercial solvent wash to dissolve and lift oils and grease. Next, decarbonize to remove baked-on carbon from combustion areas. Then finish with a mechanical clean—scraping or light grit blasting—to remove any remaining scale and roughen the surface for proper coating or sealant adhesion. This order ensures the surface is free of contaminants and properly prepared before coatings, while minimizing moisture exposure that could cause corrosion on magnesium. Water-based methods or cleaning with water alone risk corrosion, and skipping decarbonization or misordering steps would leave residues that hinder adhesion or promote deterioration.