Overview

The Dulux Avista 2 Pack Urethane Part B is the hardener component of a two-part, solvent-based urethane concrete sealer. Added to the 2 Pack Urethane Part A at the 7:1 ratio, it triggers the cross-linking cure that gives a tough, high-gloss, non-yellowing clear coating, the most durable clear sealer in the Avista range.

The 1.25L hardener is precisely matched to the 8.75L Part A resin, and together they form a complete 10L kit. The cured coating suits interior and exterior decorative concrete, including stamped, stencilled, exposed aggregate, coloured concrete, flake floors and polished concrete bench tops.

Key Features

• Chemical cross-linking cure for a tough film
• Non-yellowing, UV-stable finish
• Pre-measured kit, 1.25L plus 8.75L equals 10L
• 3 to 4 hour pot life for generous working time
• Interior and exterior use
• Contains isocyanates, handle with care

Specifications

• Pack size: 1.25L
• Mix ratio: 1 part Part B to 7 parts Part A by volume
• Kit: 1.25L Part B plus 8.75L Part A equals 10L
• Pot life: 3 to 4 hours at 25 degrees
• Full cure: 7 days
• Coverage: 3 to 10 m2 per litre

Applications

• Hardener for the high-gloss clear coat on driveways
• Two-part finish over stamped and stencilled concrete
• Flake floor topcoat
• Polished concrete bench tops

What You Need to Complete the Job

Pour the entire contents of this hardener into the 2 Pack Urethane Part A pail and mix for at least 3 minutes, then apply two thin coats within the pot life. For a single-coat, faster-curing option, the Polyaspartic Sealer system is the alternative. The range is in the Concrete Sealers category.

Frequently Asked Questions

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

No. The 7:1 ratio is critical to the curing reaction. Using less hardener leaves the coating soft, tacky or under-cured. The 3 to 4 hour pot life is already generous for a two-pack system, so plan to use the full kit in that window.

What should I do if I 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, so wear solvent-resistant gloves, safety glasses and a respirator with organic vapour cartridges. If irritation develops, seek medical attention.

How should I store leftover Part B?

Reseal the container tightly immediately after use and store in a cool, dry place away from moisture. Isocyanate hardeners react with atmospheric moisture and can skin or crystallise if the container is not sealed. Shelf life in unopened containers is about 24 months.

Can this urethane system be applied over epoxy?

Yes. This is a common and recommended system: an epoxy base coat gives adhesion and film build, and the urethane topcoat provides the UV stability and gloss that epoxy cannot. Make sure the epoxy is fully cured and lightly sanded if it is past its recoat window.