Description:

Fire-retardant protection for interior wood surfaces

Flame Control No. 133A water-based fire-retardant polyurethane varnish is available in a semi-gloss finish. Designed for use on all new or previously coated interior wood surfaces (except floors), this varnish will not lose its tint or turn white over time or during cleaning.

Features

• Dries by water evaporation to a clear semi-gloss finish.
• Class “B” fire rating on wood when applied in two coats at 450 ft²/gal per coat.
• Durable while remaining flexible.
• Retains its fire-retardant properties when exposed to high humidity.

* Note: For this fire-retardant product, the supplier does not provide a spread indication in minutes, but rather an effectiveness scale. Please note that the higher the rating, the less effective it is.

Recommended use:

• For application on interior wood surfaces on walls or ceilings, where reduced surface burning characteristics are required to meet building code requirements.
• Suitable for use over water-based stains. For use over oil-based stains, test first, as PD133-A varnish is not recommended over this type of stain.
• Schools, private residences, colleges, retirement homes, childcare centers, hospitals, prisons, apartments, hotels, factories, warehouses, retail stores, restaurants, public utilities.

Restriction

The coating is somewhat thermoplastic.

Precautions must be taken when two coated surfaces touch to prevent them from sticking together.

Ensure adequate ventilation during and after application until the coating is dry.

Avoid breathing vapors or spray mist.

Preparation

Dirt, grease, oil, wax, rust, and other foreign matter must be removed. May be applied over previously varnished surfaces in good condition. Glossy surfaces must be dulled with sandpaper. Any sanding or filling of nail holes must be done before applying No. 133A. For use over oil-based stains, test first, as oil-based stains are not recommended under this varnish.

Application

No. 133A fire-retardant varnish can be applied with a brush, foam applicator, or spray.

Stir well before use, then apply an even coat at a coverage rate of 5.5 m²/L (225 ft²/L) in one coat, or two coats at 11.0 m²/L (450 ft²/L).

Allow to dry at least 30 minutes between coats.

Do not apply when the surface or air temperature is below 10°C (50°F).

Airless spray gun guidelines

Titan 440 Impact (or equivalent)

Fluid pressure: 2000–2400 psi

Manifold and gun filter: 60 mesh

Hose diameter: ¼”

Gun: LX-80 II

Tip: 010 – .013

Q—What’s the difference vs. a standard fire-retardant varnish?

No. 133A is water-based. That means: less odor, fast drying, and easy water cleanup.

It’s a great option if you want to work indoors without making things complicated.

Q—Can I use it on a floor?

No. This product is not designed for floors.

It’s perfect for walls, trim, doors, or ceilings… but not for high-traffic floor surfaces.

For a floor, use PD-141 fire-retardant polyurethane varnish

Q—Does it really protect against fire?

Yes, but with one important condition.
You must apply 2 coats to achieve the Class B fire-retardant rating.

Think of it as a barrier: without the recommended thickness, protection isn’t complete.

Q—Can I apply it over an existing stain?

Yes, but pay attention to the type of stain. You can apply it without issue over a water-based stain, but do a small test before applying it over an oil-based stain.

Why? Because some oil bases can affect adhesion.

Q—Will the finish stay looking good over time?

Yes. The varnish is designed not to yellow, whiten, or lose its properties, even with humidity or cleaning.

So you keep a clean, stable look over time.

Q—Is it complicated to apply?

No, it’s actually quite simple:

1. Apply with a brush, foam roller, or sprayer.
2. Fast drying (about 30 minutes between coats).
3. Water cleanup for tools.

Tip: make sure the surface is clean and porous enough (lightly sanded) for better adhesion.

Technical documents