Ductmate Proseal is a water-based duct sealant for metal duct joints. It seals low, medium and high-pressure HVAC systems against air leakage, including systems up to 15 inches water gauge.
How it works
Proseal is a synthetic latex compound. Brush it onto clean joints and it dries to a flexible film that does not crack or sag. The cured film resists water, mould and humidity. It stays permanently flexible and takes latex paint. The wet odour is mild and the cured film is odourless.
Numbers that matter
- Up to 15 in. wg - seals duct systems from low to high pressure, up to 15 inches water gauge.
- UL 181B-M Listed, UL 723 Classified - tested duct product listing and classification.
- Service temperature -25°F to 220°F (about -32°C to 104°C).
- GREENGUARD Gold certified - low emissions, meets CDPH and SCAQMD test methods, LEED compliant for the EQ 4.1 credit.
- 25 sq ft per gallon at 1/16 in (about 0.6 m2 per litre), or 50 sq ft per gallon at 1/32 in (about 1.2 m2 per litre).
- Cure time 24 to 72 hours - depends on humidity, temperature and film depth. Touch dry in about 1 hour.
- VOC content passes EPA Method 24 - very low, with no added solvents.
Where to use it
- Joints on spiral, rectangular and round sheet metal ductwork.
- Supply and return ducts in low, medium and high-pressure HVAC systems.
- Indoor and outdoor duct systems (indoor/outdoor grade).
- Assemblies built to NFPA 90A and 90B ductwork installation requirements.
Application
Surfaces must be clean, dry and free of grease. Apply between 35°F and 110°F (about 2°C to 43°C). Follow SMACNA practice: sealant goes inside female fittings and outside male fittings. The film is touch dry in about 1 hour and fully cures in 24 to 72 hours. Paint with latex paint after full cure.
Clean up
Clean tools with water while the sealant is wet. Cured sealant must be removed mechanically.
Related
Need a fire rated acrylic sealant for duct seams? See Adheseal HV Duct Acrylic Sealant, tested to AS/NZS 1530.3.
Frequently asked questions
Is Ductmate Proseal® suitable for constant water immersion?
No, Proseal® is not designed for continuous submersion. While it offers excellent water resistance once fully cured and can withstand typical outdoor weather exposure, it is a duct sealant, not a waterproofing membrane for submerged applications.
What does the UL 181B-M listing mean for my HVAC project?
The UL 181B-M listing confirms Proseal® meets specific performance standards for closure systems on flexible air ducts and connectors. This ensures the sealant has been tested for critical factors like adhesion, aging, temperature, and humidity resistance, providing confidence in its use for compliant HVAC systems.
How long must I wait before pressure testing sealed ductwork?
Allow a minimum of 24 to 72 hours for Proseal® to cure before pressure testing. Applying pressure prematurely can compromise the seal, especially in cool or humid conditions where extended cure times are necessary.
Can Proseal® be applied in freezing temperatures?
No, the minimum application temperature for Proseal® is 2°C (35°F). The sealant must also be protected from freezing temperatures for at least 36 hours after application to ensure proper cure and performance.
Substrate guide
Proper surface preparation is crucial for achieving a reliable, airtight seal and ensuring system longevity.
Sheet metal ductwork
Surface prep: Ensure surfaces are clean, dry, and free of oil, grease, dust, or other contaminants. This includes common HVAC materials like galvanised steel.
Primer: Not required. Apply Proseal® directly to the prepared metal surface.
UL 181 listed flexible air ducts
Surface prep: Clean and dry the connection points between the flexible duct and metal collars, take-offs, or equipment. Remove any loose fibres or debris.
Primer: Not required. Proseal® adheres directly to flexible duct materials designed for HVAC applications.
Ductmate Proseal® Physical Properties
| Property | Value |
|---|---|
| Application Temperature (Minimum) | 2°C |
| Cure Time (Initial) | 24-72 hours |
| Pressure Rating | Up to 15 inches Water Gauge |
| Application Thickness (Sheet Metal) | 1/32 inch (0.8 mm) wet |
| Application Thickness (Flexible Duct) | 1/16 inch (1.6 mm) wet |
| Water Resistance | Excellent, once fully cured |
| Paintable | Yes, with latex or epoxy paints |
| Standards Met | UL 181B-M, UL 723, NFPA 90A/B |
| VOC Content | Low |