Mercury - Form a Gasket - 92-725921. The Mercury Form a Gasket - 92-725921 is a high-performance sealing solution designed to create a strong, durable bond between mating surfaces in marine engines and components. Formulated by Mercury for marine environments, this compound ensures leak-free performance where pre-cut gaskets aren't practical or available.. Key Features. OEM-Approved Sealant - Designed specifically for Mercury marine applications. Creates a Flexible, Long-Lasting Seal - Ideal for