Fiberlock IAQ 8500 is a black, high-build HVAC sealant for ductwork. It is designed to bridge and reinforce duct liner or duct board insulation materials, and to seal unlined ductwork before component removal, preventing fibreglass and inanimate particulate from becoming airborne.
IAQ 8500 dries to a durable, flexible, moisture-resistant protective coating with a semi-gloss finish that minimises dirt build-up on the coating surface. Its high viscosity gives maximum bridging on insulation materials and reduces sagging and dripping on the vertical and top surfaces of unlined duct.
This listing: 5 US gallon (18.9 L) pail, black, CCW SKU FL8385-5.
*Resistant to mould growth on the dry coating surface only.
Important: Read the SDS Before You Spray
The Australian SDS (ICP Group Australasia, version 1.3, revised May 2023) classifies IAQ 8500 as hazardous with the signal word Danger:
- H319 — Causes serious eye irritation
- H332 — Harmful if inhaled
- H350 — May cause cancer
- H412 — Harmful to aquatic life with long lasting effects
The SDS requires special instructions to be obtained before use, no breathing of mist, vapour or spray, use only outdoors or in a well-ventilated area, and protective gloves, clothing and eye/face protection. Spraying inside ductwork puts mist in a confined space, so plan respiratory protection, ventilation and exclusion of building occupants from the start. Fiberlock (US) specify a NIOSH-approved respirator with any R, P, N or HE filter when spraying; in Australia, select a respirator and filter to AS/NZS 1716 from SDS section 8. CCW stocks the 3M 7502 and 3M 7503 half-face respirators and the 3M 60921 organic vapour/P100 cartridge.
Key Features
- High viscosity for maximum bridging ability
- Reduces sagging and dripping
- Resurfaces and encapsulates fibreglass-lined ductwork
- Semi-gloss black finish that minimises dirt build-up
- Meets NFPA 90A/90B (US standard)
- Resists mould growth* — ASTM G-21 rating 0 (no fungal growth) per Fiberlock
- Can be applied with HVAC robotic spray applicators (contact Fiberlock for details)
*Resistant to mould growth on the dry coating surface only.
Standards — US, Not Australian
The ASTM and NFPA results quoted for IAQ 8500 (ASTM C-411 hot surface performance, ASTM E-84 Class A fire rating, NFPA 90A/90B, ASTM G-21) are US tests and standards. Fiberlock publish no Australian fire test for it. Where a job must meet Australian requirements for ductwork or building materials, confirm acceptance with the specifier, mechanical engineer or building certifier before you coat. Fiberlock themselves say to check with the local building code authority for any additional requirements.
How to Use
Surface preparation
Clean and remove all dust and loose particulate from the ductwork, being careful not to damage the insulation. Follow the duct manufacturer's instructions for cleaning. Duct cleaning and inspection equipment such as the Air-Care Cobra-7 and the Air-Care Apollo inspection camera is in our duct cleaning range.
Do not apply when air or surface temperature is below 10 °C, when drying conditions are poor, or when surfaces are above 15% moisture content.
Lead paint: Fiberlock's data sheet warns that scraping, sanding or removing old paint may release lead dust, which is toxic. In older Australian buildings, assume lead paint may be present until it is tested, and follow your state WHS requirements for lead before you disturb painted surfaces.
Application tools
- Brush: synthetic, nylon or polyester bristle
- Roller: synthetic fibre, 3/8 in (10 mm) nap or longer
- Airless spray: 0.019–0.023 in tip at 2,500–3,000 psi (172–207 bar)
Application
Mix thoroughly to a uniform consistency. Apply to all surfaces by brush or airless spray. The application rate varies with the porosity of the insulation. Apply one coat by airless spray, or two coats by brush; porous surfaces may need more. Make sure surfaces are completely sealed.
Circulate fresh air through the HVAC system to help dry the coating, and exhaust that air outside the building. Clean tools and drips with warm soapy water before IAQ 8500 dries, and dispose of all waste as the SDS and your local authority require, not into stormwater. Interior use only.
Coverage and Drying
| Coverage — smooth surfaces | 4.9–14.7 m²/L (200–600 ft²/US gal) |
|---|---|
| One 18.9 L pail, smooth (our calculation) | about 93–278 m² per coat |
| Coverage — porous surfaces | 1.8–4.3 m²/L (75–175 ft²/US gal) |
| One 18.9 L pail, porous (our calculation) | about 34–81 m² per coat |
| Touch dry (21–25 °C, 50% RH) | 1–2 hours |
| Recoat | 4–8 hours |
| Minimum application temperature | 10 °C |
Technical Data
From the Fiberlock product data sheet linked below. Imperial figures are the manufacturer's; the metric equivalents are ours.
| Brand / product code | Fiberlock (ICP Construction) IAQ 8500, 8385 Black |
|---|---|
| CCW SKU | FL8385-5 |
| Pack | 5 US gallons (18.9 L) |
| Solids by weight (±2%) | 50% |
| Solids by volume (±2%) | 39.9% |
| Viscosity at 21 °C | 105–110 Krebs units |
| Specular gloss at 60° | 74 ±4 (semi-gloss) |
| VOC | 89 g/L (calculated) |
| Weight | 10 lb/US gal ±0.5 (about 1.20 kg/L) |
| Flash point | Non-combustible |
| Shelf life | 36 months minimum in the original sealed container |
| Hazard classification (Australian SDS) | Hazardous — Danger (H319, H332, H350, H412) |
| Transport (Australian SDS) | Not regulated as dangerous goods (ADG, IATA, IMDG) |
Storage and Precautions
Store in a dry place between 4.5 °C and 32 °C and keep from freezing. Stir thoroughly. Do not mix with any other coatings, solvents or colours in oil.
The IAQ 8500 coating is resistant to mould only on the surface of the coating. No mould resistance claim is made other than to the coating itself, and the product does not protect users or others against food-borne or disease-causing bacteria, viruses, germs or other organisms.
CPVC pipe: Fiberlock advise checking pipe markings and contacting the pipe manufacturer before applying any Fiberlock product to CPVC pipe, as some coating chemicals can cause stress cracking.
A note on earlier versions of this page
Earlier versions of this page gave IAQ 8500 the coverage (100–200 ft²/gal smooth) and recoat time (8–16 hours) of IAQ 8000, and referred to IAQ 8000 in its clean-up and precaution text. The figures above are from the IAQ 8500 data sheet: 200–600 ft²/gal smooth, 75–175 ft²/gal porous, recoat 4–8 hours. A duplicate safety data sheet link has also been removed.
Frequently Asked Questions
IAQ 8500 or IAQ 8000?
Both are high-build duct insulation sealers with the same job. IAQ 8500 is black with a higher-gloss finish; IAQ 8000 is white. Choose on colour and the job specification.
When would I use IAQ 7000 instead?
IAQ 7000 is a lower-viscosity penetrating coating for locking down residual particulate in lined duct after cleaning. IAQ 8500 is the high-build choice for bridging and reinforcing damaged liner or duct board.
Does it stop mould growing in the duct?
It resists mould growth on its own dry surface only. Clean the duct first and correct the moisture source.
Is it safe in an occupied building?
The SDS classifies it Danger, including H350 (may cause cancer) and H332 (harmful if inhaled). Keep occupants away from spray mist, circulate fresh air through the system while it dries and exhaust that air outside. Follow SDS section 8 for PPE.
Does it meet Australian fire requirements for ductwork?
Fiberlock publish US results only. Confirm acceptance with the specifier or certifier before use on a job that must meet Australian requirements.
Is it dangerous goods?
No. The Australian SDS lists it as not regulated for road, air or sea transport. It is still a hazardous chemical.
Safety & Technical Data Sheets
Related Products
- Fiberlock IAQ 8000 HVAC Insulation Coating (White)
- Fiberlock IAQ 7000 Penetrating HVAC Coating
- Air-Care Cobra-7 Air Duct Cleaning Machine
- Air-Care Apollo Air Duct Video Inspection Camera
- 3M 7500 Series Half Face Respirator
- Fiberlock collection
Not sure whether IAQ 8500, IAQ 8000 or IAQ 7000 suits the duct you are working on? Tell us the duct type (lined, duct board or bare metal) and the job specification, and we will help you choose before you order.
