POR-15 POR 15 45804 Gloss Black BlackCote - Top Coat Over Quart Top Coat is a direct-to-metal coating designed to work incredibly well in all applications where there is a need to preserve substrates susceptible to corrosion. Under exposure to sunlight and weather POR-15 Top Coat has exceptional long-term gloss and color retention. POR-15 Top Coat can be applied directly to metal substrates with no need for a primer or undercoat and is formulated to form a robust barrier that sheds moisture to provide long lasting protection. POR-15 Top Coat has excellent adhesion and when used over POR-15 RUST PREVENTIVE COATING the products create a system works to provide a permanent barrier to corrosion.