An acrylic-based sealing product for round ventilation ducts. The product contains no harmful solvents or odours. Once installed, the duct seal provides flexible joints, which can be coated with paint, ensuring excellent adhesion to galvanized steel sheets, coated steel sheets or stainless steel sheets. Once the duct seal compound has cured, it resists varying weather conditions. The product is intended for indoor and outdoor use. When fully cured, the duct seal compound is waterproof.