Mercury - Light Gray Primer Enamel Spray Paint 12 oz Marine Primer 80287852. Overview. Before you spray on that final coat, make sure your surface is ready with Mercury Marine 80287852 Light Gray Primer Enamel Spray Paint. This durable 12-ounce aerosol primer creates the perfect base for Mercury finish paints, improving adhesion and helping you achieve a smooth, professional-grade finish. It seals out moisture, prevents rust, and promotes even coverage on engine cowls, drives, propellers, or low