Dulux Avista 2 Pack Urethane Part B 1.25L — Premium High-Gloss Concrete Sealer Hardener

The Dulux Avista 2 Pack Urethane Part B is the hardener component of a premium two-part, solvent-based urethane concrete sealer. When added to 2 Pack Urethane Part A (8.75L, sold separately) at a 7:1 ratio, it triggers the chemical cross-linking reaction that transforms the liquid resin into an exceptionally tough, high-gloss, non-yellowing clear coating — the most durable clear sealer in the Dulux Avista range.

This 1.25-litre hardener is precisely measured to match the 8.75L Part A resin — the two together form a complete 10L kit. The resulting cured coating is suitable for both interior and exterior decorative concrete, including stamped, stencilled, exposed aggregate, coloured concrete, flake flooring systems, and polished concrete bench tops.

Important: This is Part B of a two-part system. You must also purchase Dulux Avista 2 Pack Urethane Part A (8.75L). Mix the entire contents of Part B into Part A — do not attempt to split the kit. Pot life after mixing is 3–4 hours at 25 °C.

Key Features & Benefits

• Chemical Cross-Linking Cure: Produces a coating far tougher than solvent-evaporation sealers — resistant to fuels, oils, and cleaning chemicals.
• Non-Yellowing System: UV-stable formulation keeps decorative concrete looking fresh without ambering over time.
• Pre-Measured Kit: 1.25L Part B + 8.75L Part A = 10L complete kit — no measuring, no waste, no ratio errors.
• 3–4 Hour Pot Life: Generous working time for large-area application.
• Interior & Exterior: Same premium finish for indoor polished concrete and outdoor driveways alike.

System Specifications (when mixed with Part A)

• Mix Ratio: 1 part Part B : 7 parts Part A (by volume)
• Kit Size: 1.25L Part B + 8.75L Part A = 10L
• Pot Life: 3–4 hours at 25 °C
• Tack-Free: 30 min – 2 hours
• Full Cure: 7 days
• Coverage: 3–10 m² per litre (10L kit covers 30–100 m² per coat)

Application Guidance

Pour the entire contents of Part B (1.25L) into the Part A pail (8.75L). Mix thoroughly with a paint stirrer for a minimum of 3 minutes. Apply by brush, mohair roller (4 mm nap), or airless spray within the 3–4 hour pot life. Two coats are recommended.

Frequently Asked Questions

1. Can I use less Part B to extend the pot life?

No. The 7:1 ratio is critical to the chemical curing reaction. Using less hardener will result in incomplete curing — the coating may remain soft, tacky, or fail to develop proper hardness and chemical resistance. The 3–4 hour pot life is already generous for a two-part system; plan your work to use the full kit within this window.

2. What happens if I accidentally splash Part B on my skin?

Wash immediately with soap and plenty of water. Urethane hardeners contain isocyanates which can cause skin and respiratory sensitisation. Wear solvent-resistant gloves, safety glasses, and a respirator with organic vapour cartridges when handling. If irritation develops, seek medical attention.

3. How should I store leftover Part B?

Reseal the container tightly immediately after use. Store in a cool, dry place away from moisture — isocyanate hardeners react with atmospheric moisture and can form a skin or crystallise if the container is not properly sealed. Once opened, use within a few months for best results. Shelf life in unopened containers is approximately 24 months.

4. Can this urethane system be applied over epoxy?

Yes — and this is actually a common and recommended system. An epoxy base coat provides excellent adhesion and film build, while the urethane topcoat provides the UV stability and gloss that epoxy alone cannot. Ensure the epoxy is fully cured and lightly sanded if beyond its recoat window before applying the urethane.