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EnglishBarrier Primer High Corrosion Powder Coating
Industrial-grade protective coating solutions: environmentally friendly, durable, and cost-effective.
Intro to Barrier Primer High Corrosion Powder Coating
Barrier Primer High Corrosion Powder Coatings are the first, most critical layer in a duplex coating system designed to provide maximum corrosion protection in highly aggressive environments (e.g., C4 and C5 atmospheric corrosivity classifications). These primers are high-build formulations, typically based on high-density Epoxy resins (sometimes with zinc additives), engineered to create a thick, chemically inert, and highly impermeable physical barrier against moisture, chlorides, and oxygen, shielding the pre-treated metal substrate.
Duplex System and Impermeability
A single topcoat is insufficient for long-term protection in harsh industrial or coastal settings. The barrier primer forms the foundation of the Duplex System. It is formulated to achieve a high film thickness (often 100 to 200 microns) and relies on a low permeability index to dramatically slow the ingress of corrosive media to the steel surface. Unlike zinc-rich primers, which offer sacrificial (galvanic) protection, a pure barrier primer focuses on physical separation and chemical resistance. The primer provides the necessary anti-corrosion layer, and a UV-stable topcoat (like Polyester or Polyurethane) is then applied over it to protect the primer itself from sunlight and physical damage. This multi-layer approach ensures extended corrosion-free service life, often exceeding 10 years in severe environments, verified by thousands of hours of Salt Spray (ASTM B117) testing.
Specifications
| Property | Standard Barrier Primer Value (C4/C5) |
| Chemical Base | High-Build, High-Molecular Weight Epoxy |
| Film Thickness (Typical) | 100 to 200 microns (4 to 8 mils) |
| Permeability Index | Very Low (Critical for barrier defense) |
| Corrosivity Classification | C4 to C5 (Heavy Industrial/Marine) |
| Salt Spray Resistance (B117) | ≥2000 hours (Minimal creep when topcoated) |
| Required Topcoat | Yes (Epoxy primer is not UV stable) |
| Application Focus | Critical Infrastructure, Severe Environments |
| Color | Often Red, Gray, or Black (Visual contrast for topcoat) |
Application Fields
- Offshore and Coastal Structures: Platforms, pier supports, and beachfront railings.
- Heavy Industrial Machinery: Equipment in chemical or heavily polluted industrial zones.
- Automotive Underbody and Frames: Components requiring maximum protection against road salts and moisture.
- Wastewater and Utility Infrastructure: Metalwork exposed to high humidity and corrosive gases.
- High-Value Assets: Where recoating costs or failure risks are extremely high.
Key Characteristics
- Fundamental Barrier Defense: Creates a thick, highly impermeable physical shield against corrosive agents.
- High Film Build: Easily achieves the heavy film thickness necessary for C4/C5 protection ratings.
- Enhanced Adhesion: Formulated for superior bond strength to properly pre-treated substrates.
- Long-Term System Performance: Extends the service life of the entire duplex coating system.
- Chemical Resistance: Inherits the excellent chemical and water resistance of the Epoxy backbone.
Comparison: Barrier Primer vs. Standard Single Coat
| Feature | Barrier Primer Duplex System | Standard Single-Coat Powder |
| Corrosion Protection | Maximum (C4/C5 rated) | Moderate (C2/C3 rated) |
| Protection Mechanism | Thick Physical Barrier + Topcoat Seal | Single Aesthetic/Protection Layer |
| Film Thickness | High (≥100μm primer +60μm topcoat) | Standard (∼80μm) |
| Salt Spray Hours | ≥2000 hours | ≤1000 hours |
| Cost | Highest (Two-coat process) | Standard |
Why choose us
Customization: We have a strong R&D team,and we can develop and produce products according to different requirement of customers.
Cost: We have our own raw material production center.So we can offer the most favourable price and good-quality products directly.
Quality: We have our own testing lab and the most advanced and complete inspection equipment, which can ensure the quality of our products.
Capacity: Our annual production capacity is over 30000 tons, we can meet the needs of different customers with diverse purchase quantity.
Service: We focus on developing high-quality products for top-end markets. Our products are in line with international standards, and are mainly exported to Europe, America, Southeast Asia, South America and other destinations around the world.
Shipment: We are only 200 kilometers away from the Shanghai Port and 230 kilometers to Ningbo port, it is very convenient and efficient to ship goods to any other countries.
Customization
Quality
Capacity
Service
Shipment
Frequently Asked Questions (FAQs)
- Q: Can a barrier primer be used as a single coat?
- A: Only in interior, non-UV exposed environments. Since the primer is typically Epoxy, it will rapidly chalk and degrade if exposed to sunlight, requiring a UV-stable topcoat for any outdoor use.
- Q: Is a barrier primer or a zinc-rich primer better for corrosion protection?
- A: Both are excellent. Zinc-rich offers galvanic (sacrificial) protection, while a barrier primer offers physical impermeability. The choice depends on the specific corrosive environment and substrate material (zinc primers are usually only for steel).
- Q: What is the typical recoat window between the primer and the topcoat?
- A: The recoat window is critical. It must be short enough to ensure chemical bonding of the topcoat to the primer (often 2 to 24 hours of full cure) or require mechanical scuffing if the window is exceeded.
Selection Guide: Barrier Primer High Corrosion
Select Barrier Primer High Corrosion Powder Coating when:
- The component is located in a highly corrosive industrial or marine environment (C4/C5).
- Maximum, long-term corrosion defense (often 10+ years) is the primary engineering requirement.
- A duplex system (primer + topcoat) is specified to achieve the required total film thickness and protection.
- The coating must provide a physically impermeable barrier against salt and moisture ingress.
- The application requires the superior adhesion and chemical resistance of an epoxy-based primer.
