Primax Hi-Build Undercoat
Primax Hi-Build Undercoat
Primax Hi-Build Undercoat is a fast-drying undercoat designed to provide excellent filling and adhesion properties. It creates a smooth, sandable base that helps prepare surfaces properly before applying the final topcoat.
A high-quality finish depends on the condition of the surface underneath. If the base is rough, uneven or poorly prepared, the final coat may not look smooth or may not bond properly. Primax Hi-Build Undercoat helps improve the surface by filling minor imperfections and supporting better adhesion for the finishing coat.
It is highly recommended for interior and exterior surfaces, including wood, metal, iron and other suitable prepared surfaces. With overnight sanding capability, good coverage and compatibility with common application methods, it is a practical choice for painters, contractors and project users who need a reliable base coat before topcoat application.
Why Undercoat Is Important Before Topcoat
Undercoat plays an important role in the overall paint system. It helps create a smoother base, improves adhesion and supports better final appearance. Without proper undercoating, the topcoat may show uneven patches, weak coverage or surface marks.
On wood and metal surfaces, undercoat helps prepare the surface for a cleaner and more durable finishing layer. It also supports better sanding, which is important when a smooth and refined topcoat is required.
Primax Hi-Build Undercoat is designed for projects where surface preparation matters. Its fast-drying and sandable nature helps painters achieve a more professional final result.
Key Benefits
- Fast drying: Touch dry in approximately 1–2 hours under normal conditions.
- Excellent filling properties: Helps fill minor surface defects before topcoat application.
- Strong adhesion: Supports better bonding between the surface and final paint system.
- Smooth sandable base: Can be sanded after overnight drying for a refined finish.
- Interior and exterior use: Suitable for properly prepared surfaces inside and outside.
- Suitable for wood, metal and iron: A versatile undercoat for different surface types.
- Multiple application methods: Can be applied by brush, roller or spray.
- Good coverage: Covers approximately 9–11 m² per litre per coat under normal conditions.
Recommended Use Areas
Primax Hi-Build Undercoat is suitable for surfaces where a smooth, adhesive and sandable base is required before applying the final finish.
- Interior wood surfaces
- Exterior wood surfaces
- Metal surfaces
- Iron surfaces
- Doors and windows
- Wooden frames
- Metal frames
- Gates and grills
- Furniture and decorative surfaces
- General maintenance painting projects
Suitable Surfaces
This undercoat is recommended for properly prepared interior and exterior surfaces, including:
- Wood
- Metal
- Iron
- Interior surfaces
- Exterior surfaces
- Other suitable prepared surfaces
Pack Sizes
- 0.91 Litre
- 3.64 Litre
Color Range
- Light Grey
- White
- Pink
- Green
Key Ingredients
| Component | Detail |
|---|---|
| Pigment | Inert Filler and Lightfast Pigments |
| Binder | Alkyd Resin |
| Solvent | Mineral Turpentine |
| Flashpoint | 34°C |
Drying Time
| Stage | Time |
|---|---|
| Touch Dry | 1–2 Hours |
| Recoat | 4–6 Hours |
Drying time may vary depending on temperature, humidity, air movement, film thickness and actual site conditions. For sanding, allow overnight drying for best results.
Application Methods
Primax Hi-Build Undercoat can be applied using common professional painting methods.
- Brush
- Roller
- Spray
Recommendation: Suitable for conventional spray through most equipment.
Coverage
Primax Hi-Build Undercoat gives approximate coverage of:
- 9–11 m²/litre/coat under normal conditions
Actual coverage may vary depending on surface texture, porosity, application method, thinning ratio and film thickness.
Thinning Ratios
Follow the recommended thinning ratio according to the application method for smooth flow and proper film build.
| Application Method | Thinning Ratio |
|---|---|
| Brush or Roller | 10–25% |
| Conventional Spray | 30–40% |
Cleanup
Clean all equipment immediately after use with mineral turpentine. Timely cleaning helps keep brushes, rollers and spray equipment in better condition for future use.
Surface Preparation
Before applying Primax Hi-Build Undercoat, make sure the surface is clean, dry and free from dust, grease, oil, rust, loose paint, weak coating and other contamination. Proper surface preparation helps the undercoat bond better and improves the performance of the final finish.
For wood surfaces, sand properly to remove roughness and create a smooth base. For metal and iron surfaces, remove rust, mill scale and loose coating by sanding, scraping or wire brushing. The surface should be stable before application.
A clean and properly prepared base helps the undercoat fill minor surface imperfections and gives the topcoat a smoother, more professional appearance.
Application Guidance
Application
Apply Primax Hi-Build Undercoat evenly by brush, roller or spray. Avoid over-application, as very thick coats can affect drying, sanding and final smoothness.
Drying and Sanding
Allow the undercoat to dry properly before sanding or recoating. It becomes touch dry in approximately 1–2 hours and can be recoated in 4–6 hours under normal conditions. For a smoother sandable base, overnight drying is recommended.
Topcoat Application
Once the undercoat is fully dry, sand the surface smoothly and remove all sanding dust before applying the selected topcoat. This helps improve the appearance and durability of the final finish.
Common Mistakes to Avoid
Applying on Dirty or Oily Surfaces
Dust, oil and grease can reduce adhesion. Clean the surface properly before applying undercoat.
Skipping Rust Removal
On metal and iron surfaces, rust and loose coating should be removed before application to support better durability.
Applying Too Thick a Coat
Very thick coats may dry slowly and become difficult to sand. Apply an even coat according to the surface requirement.
Sanding Too Early
For the best smoothness, allow proper drying before sanding. Sanding too early can damage the coating or create an uneven base.
Leaving Sanding Dust on the Surface
Always remove sanding dust before applying the topcoat. Dust can affect adhesion and make the final finish look rough.
Why Choose Primax Hi-Build Undercoat?
Primax Hi-Build Undercoat is designed for users who want a smooth, sandable and adhesive base before applying the final finish. Its excellent filling and adhesion properties help improve surface preparation and support a more professional result.
It is suitable for interior and exterior surfaces, including wood, metal and iron. With fast drying, multiple color options, practical coverage and compatibility with brush, roller and spray application, it is useful for both small and large painting projects.
For painters, contractors and homeowners, Primax Hi-Build Undercoat provides a reliable foundation that enhances the durability and appearance of the final topcoat.
FAQs
What is Primax Hi-Build Undercoat used for?
It is used as a base coat before applying topcoats. It helps create a smooth, adhesive and sandable surface.
Is it fast drying?
Yes, it becomes touch dry in approximately 1–2 hours under normal conditions.
Can it be sanded?
Yes, it provides a smooth, sandable base after overnight drying.
Which surfaces is it suitable for?
It is suitable for properly prepared interior and exterior surfaces, including wood, metal and iron.
What pack sizes are available?
Primax Hi-Build Undercoat is available in 0.91 litre and 3.64 litre pack sizes.
What colors are available?
It is available in Light Grey, White, Pink and Green.
How can it be applied?
It can be applied by brush, roller or spray.
What is the thinning ratio?
For brush or roller application, thinning is 10–25%. For conventional spray application, thinning is 30–40%.
What is the coverage?
Coverage is approximately 9–11 m² per litre per coat under normal conditions.
How should tools be cleaned after use?
Clean all equipment immediately after use with mineral turpentine.
Conclusion
Primax Hi-Build Undercoat is a fast-drying undercoat designed with excellent filling and adhesion properties. It provides a smooth, sandable base overnight and is recommended for interior and exterior surfaces, including wood, metal and iron. With good coverage, practical application methods and multiple color options, it helps improve the durability and appearance of the final topcoat.
Contact Primax Paints for product availability, dealer support and application guidance.
