Ductmate Proseal® is a premium, water-based duct sealant engineered specifically for sealing metal joints and connections in low, medium, and high-velocity HVAC systems operating at pressures up to 15 inches Water Gauge (approx. 3740 Pa). This high-performance sealant ensures airtight seals, contributing to improved system efficiency and energy savings. Critically, Proseal® is UL 181B-M Listed and UL 723 Classified (Flame Spread 0, Smoke Developed 5), demonstrating compliance with key North American safety and performance standards often referenced in Australian building codes for HVAC installations. Its water-based formulation offers significant advantages: low odour, easy cleanup with soap and water (when wet), and low VOCs making it LEED® Compliant. Proseal® applies smoothly with low brush drag, reducing labour time, and cures to a tough, permanently flexible seal that resists cracking, water, mould, and UV degradation, suitable for both indoor and outdoor applications.
Surface Preparation: Ensure surfaces of ductwork joints are clean, dry, and free from any dirt, oil, grease, water, or foreign matter before application for optimal adhesion.
Cure Time: Proseal® typically becomes dry to the touch in approximately 1 hour under standard conditions. Full cure, required before pressure testing the system or covering duct ends, takes 24 to 72 hours or more, depending heavily on ambient temperature, humidity, and application thickness. Allow longer cure times in cool or humid conditions typical of some Australian environments.
Coverage Rate: Apply at the recommended wet film thickness. For sealing sheet metal joints, apply at approximately 1/32" (0.8mm) thick, which covers roughly 1.2 square metres per litre (50 sq ft/gal). For sealing connections involving UL 181 listed flexible air ducts, a thicker coat of 1/16" (1.6mm) is required, covering approximately 0.6 square metres per litre (25 sq ft/gal).
Application Temperature Range: Proseal® can be applied in temperatures ranging from 2°C to 43°C (35°F to 110°F). Store sealant at room temperature for at least 24 hours before use for best brushability. Do not apply if rain or freezing temperatures are expected within 36 hours.
Service Temperature Range: The cured sealant performs effectively in typical HVAC operating temperatures, ranging from -18°C to 104°C (0°F to 220°F).
Chemical Properties: Proseal® is a synthetic latex emulsion (water-based). It dries to a tough, permanently flexible seal with excellent resistance to water, mold/mildew, and UV.
Q: Is Proseal® completely waterproof? Can water run over it?
A: Yes, once fully cured, Proseal® exhibits excellent water resistance. It's designed for indoor/outdoor use and can withstand typical weather exposure on external ductwork. However, it's a duct sealant, not a pond liner or roofing membrane for constant immersion.
Q: How critical is the application thickness for Proseal®?
A: Applying the correct thickness is important for performance. The TDS recommends 1/32" (~0.8mm) wet film thickness for sheet metal joints and a thicker 1/16" (~1.6mm) for sealing connections to flexible air ducts to ensure a robust, airtight seal that meets UL listing requirements.
Q: Can I paint over Proseal® Duct Sealant?
A: Yes, Proseal® is paintable once fully cured. The TDS recommends using latex (water-based) or epoxy-based paints for best results. Allow the sealant to cure completely (24-72+ hours) before painting.
Q: What does the UL 181B-M listing mean?
A: UL 181B covers closure systems for flexible air ducts and connectors. The "-M" specifically designates "Mastic" (sealant). This listing indicates that Proseal® has been tested and meets specific UL requirements for adhesion, aging, temperature, and humidity resistance when used as part of a listed closure system for flexible ducts.
Q: How long do I really need to wait before pressure testing the duct system?
A: The TDS recommends waiting a minimum of 24 to 72 hours, but notes that longer times may be required depending on temperature and humidity. Applying pressure before the sealant has adequately cured can compromise the seal. It's best to err on the side of caution, especially in cool or humid conditions.
Q: Is this product suitable for use under Australian building codes?
A: Proseal® meets stringent North American standards (UL, NFPA) related to fire safety and performance for HVAC systems. While these standards are often recognised or referenced, always verify compliance with the specific requirements of the National Construction Code (NCC) and relevant Australian Standards (e.g., AS 4254 series) with the project engineer or certifier.