Novol 37542 Protect 333 Acrylic Filler – Black (3L)
Engineered for high-volume restorations and commercial refinishing, Novol Protect 333 is a professional-grade 2K acrylic primer/filler. This 3-litre unit in Black is specifically designed to provide a dark, high-opacity base that is perfect for vehicles finishing in black, dark grey, or deep metallic colors.
Unlike the 5:1 ratio of the Protect 330 series, the Protect 333 is a 3:1 system, offering a thicker, more robust resin structure that excels in filling deep sanding marks and smoothing out major surface imperfections.
The Power Mix: 3:1 Ratio
This is a two-component (2K) product that requires a dedicated hardener to cure.
- Mixing Ratio: 3:1 (3 parts Primer : 1 part Hardener).
- Required Hardener: Novol H 5520 (Standard) or H 5521 (Fast).
- Volume Note: To use the full 3L tin, you will need exactly 1.0 Litre of hardener.
Key Features & Benefits
- High-Solid (HS) Content: Features a high concentration of resins and pigments, allowing for fewer passes to reach a high-build thickness of 100–120 µm.
- Excellent Hiding Power: The deep black pigment provides a uniform ground coat that prevents "shadowing" when applying dark topcoats.
- Wet-on-Wet Capability: Can be thinned (approx. 20%) to be used as an "isolating" primer that can be overcoated shortly after application without sanding.
- Superior Leveling: The low-viscosity flow ensures a smooth finish that minimizes the amount of block-sanding required.
- Industrial Protection: Offers reliable anti-corrosive properties and excellent mechanical strength once fully cured.
Professional Application Strategy
For a 3-litre batch, consistency is your best friend.
- Preparation: Degrease with Novol Plus 780. Sand the substrate with P240–P320 for dry sanding.
- Mixing: For the 3:1 ratio, use a graduated mixing cup.
- High Filling: 3:1 + 10% Acrylic Thinner.
- Wet-on-Wet: 3:1 + 20% Acrylic Thinner.
- Application: Apply 2 to 3 layers, allowing a 5–10 minute flash-off time between coats.
- Sanding: Once cured, dry sand with P400–P500 to prep for the topcoat.
Expert Insight: Black primer is a "diagnostic" tool. It makes it incredibly easy to see if you've missed any spots during the sanding process; as you sand, any high spots will become dull, while low spots (where the primer hasn't been touched by the paper) will remain glossy.
