Sherwin-Williams Protective & Marine Coatings now offers its Opti-Check Optically Active Pigments (OAP) in a variety of coatings products, allowing tank lining applicators to check the coating instantly for pinholes, holidays and other discontinuities and verify uniform coverage and proper film thickness. A ‘civilian' application developed from a proven Sherwin-Williams technology supplied to the U.S. Navy, the fluorescing technology significantly extends the service life of tank coatings simply by illuminating insufficient film thickness wherever it occurs through the use of a portable ultraviolet flashlight. Pinholes, holidays and improper film thickness will contrast to the fluorescing coating. The result: pinholes as small as 0.25 mils can be identified and repaired before a tank is returned to service. Proper film thickness and uniform coverage can now be verified instantly. The OAP technology works in conjunction with an inexpensive ASTM E 2501-approved ultraviolet light source. "Sherwin-Williams OAP technology has quickly gained acceptance by both applicators and owners of water and fuel tanks and in marine ballast tank applications," said W. Doni Riddle, vice president, Sherwin-Williams Protective & Marine Coatings. "Offering the technology in other tank coating products provides applicators and owners easy identification of pinholes, holidays and insufficient film thickness and enables them to extend coating life, reducing downtime and saving money."