ST-821 Extra-Hard Matte Topcoat for bodywork - Gloss 20°

Two-component Bodywork Matte Topcoat

The ST-821 20° Matte Topcoat is part of Stardust® Variance Range, and is the second most Matt Clear Coat, just before the ST820 40° Semi-Matt Clear Coat and after the ST-822 4° Extreme Matte Clear Coat.

Gloss grades: 20°

Performances

Excellent hardness: 3H hardness scale (UN 78267:199)
Perfect resistance to bad weather, UVs, petrol, alcohols

This is an extra hard clear coat originally designed for automotive and motorcycle body, providing robustness and resistance to aggressive factors such as abrasion, washing, scratching, weather, fuel.
It is however widely used by furniture manufacturers for indoor and outdoor spaces (furniture, kitchens, wood floors, swimming pools, etc.)

ST821 Matte Topcoat innovations:

Matt Topcoats usually demonstrate a degree of fragility to scratches, cleaning, traces of products, and shocks.
The Stardust® Variance Mat range uses new nano-technologies to combine matte effect and extreme hardness. The quality of the Stardust® French-made Matte Clear Coats matches that of the best matte topcoats from the world's biggest brands. It constitutes a notable advance in the field of automotive coatings.

Matt aspect 20°
The ST-821 Matte Topcoat is not glossy and doesn't reflect the light. It creates a smooth and neutral surface while keeping a perfect transparency.
It does not produce a whitish effect, when a thin coat is applied(20-25µm), and thus does not alter the colours and background shades.

Matte Topcoat for all substrates
The product can be applied on all paints and topcoats, but also directly on metals and plastics thanks to its exceptional adhesion properties.

Details of the ST821 Kit Offer:

Complete kit including varnish (1L or 5L), hardener H423 (0.2L or 1L) and thinner (0.15L or 0.5L)
Yield 10m² / L per coat

How to mix it?
Shake the topcoat container.
Polyurethane. It's recommended to mix a hardener with the topcoat and add thinner to modify the liquidity of topcoat:

For 100 parts of ST-821 Matte Topcoat:
Weigh 20 parts of H423 Hardener
Weigh 10 parts of PU Acrylic Thinner
Leave the mixture for 5 min before applying
Useful life once mixed: 4h

Application

Spray gun 1.0 - 1.5mm
Roller
Apply 1-2 thin passes
(120g/m²)
The Matte Topcoat dries extremely fast and successive passes can be applied without waiting interval between each coat.
The matte effect appears during the drying process.

Drying at 20 °C:
- Dry to the touch: 30min
- Through-drying: 4h
- Overcoating: 5h

Matte varnishes dry quickly.

When painting large parts, it is recommended to reduce the drying speed in order to avoid "seam" or "dusting" defects, thanks to Extra Slow Thinner 708.

Technical specifications :

Density : 0.92kg/L
VOC : 40%

Quality Tests for ST-821 Matte Topcoat:

Adhesion Tests (according to ISO-2409/1996) : Passed
Cold-Check Test (according to UN-48205) : Passed
Moisture (according to DIN-50017) : Passed
UVs (according to ISO-11341) Passed, no colour change was noted
Pencil Hardness Test (according to UN 78267 :1996) : 3H
Chemical Resistance (according to ISO-2811) : no changes were noted according to 5 tests.

Complete car varnishing and large surfaces :

In order to slow down the drying time (a little too fast for clearcoats of this type), it is possible to request the replacement of the normal thinner
by a slow diluent. Just write us this clarification by email just after your order.