Special Functional Coatings
Dachin Bitumen 730
Thick slurry epoxy coal tar coating
Composition
The coating is formulated by dispersion and grinding of epoxy resins, anti-corrosive pigments, asphalt, fillers, and additives. The second component is a specially modified polyamide curing agent.
Key Characteristics
High solids content, excellent sag resistance, thick film formation in a single coat, strong adhesion, and superior water resistance, salt spray resistance, and corrosion protection.
Applications
Ideal for corrosion protection of ship bottoms, waterlines, decks, hulls, and other metal surfaces, as well as buried pipelines requiring long-term corrosion resistance.
Technical Specifications
| Film Appearance | Black, smooth finish |
|---|---|
| Volume Solids Content (%) | 54±1 |
| Density (kg/L) | 1.41±0.04 |
| Fineness (μm) | ≤50 |
| Impact Resistance (kg·cm) | ≥50 |
Packaging Specifications
| Weight (kg) | Volume (L) | |
|---|---|---|
| Component A | 25 | 16.7 |
| Component B | 2.5 | 2.7 |
| Total | 27.5 | 19.4 |
Basic Parameters
| Mix Ratio | Weight Ratio A:B = 10:1 |
|---|---|
| Volume Ratio A:B = 6.2:1 | |
| Pot Life | 5°C: 6h; 15°C: 5h; 25°C: 4h |
| Theoretical Coverage | ~9 m²/L (60μm dry film) |
Recoat Intervals
| Temperature (°C) | Surface Dry (min) | Hard Dry (h) | Recommended Recoat Window | |
|---|---|---|---|---|
| Minimum | Maximum | |||
| 5 | 180 | 16 | 16 | 3 months |
| 15 | 120 | 12 | 12 | |
| 25 | 90 | 10 | 10 | |
| 35 | 60 | 8 | 8 | |
Data derived from standard film thickness on steel test panels.
Application Guide
- Dachin Bitumen 730 Heavy-Body Epoxy Asphalt Coating can be applied via conventional spraying, airless spraying, or brushing. Cure requires temperatures above 5°C, with maximum application temperature at 40°C. Coating material temperature should be above 15°C. Surfaces must remain at least 3°C above dew point and below 85% relative humidity.
- Ensure substrate surfaces are clean and dry. Adequate ventilation is required in confined spaces.
- Mix the base material and curing agent strictly by ratio before use. Use only what is needed within 4 hours after mixing.
- Keep all tools dry and clean before and after application.
Compatible Coatings
Can be used as a standalone coating underwater or in buried environments. For atmospheric exposure, recommend topcoats: Dachin PU 770 Polyurethane Coating, Dachin PS 990 Acrylic Polysiloxane Coating, or Dachin FC 880 Fluorocarbon Coating.
Coating Layers
Suggested application: 1 coat via airless spray or 2-3 coats via conventional spray, 2 coats via brush/roller. Target dry film thickness: 80-150μm.
Surface Preparation
Steel Substrates: Blast clean to Sa 2.5 (ISO 8501-1:1988) or SSPC SP10. Surface roughness should be Rz:40-75μm. Insufficient roughness may reduce adhesion and increase cracking risk. Excessive roughness may cause pitting at peaks. If blasting is not feasible, St3 cleaning is acceptable. Remove all dust, oil, and contaminants from steel surfaces.
Mixing
This product is supplied in two components (A base, B curing agent). Thoroughly stir each component with power tools before mixing. Follow strict ratios and re-stir after mixing.
Application Methods
| Application Type | Thinner | Dilution (%) | Nozzle Size (mm) | Pressure (MPa) |
| Airless Spray | Dachin Thinner X17 | 0-5 | 0.4-0.48 | 12-15 |
| Conventional Spray | Dachin Thinner X17 | 3-15 | 1.5-2.0 | 0.3-0.4 |
| Roller/Brush | Dachin Thinner X17 | 0-3 | N/A | N/A |
Dilution calculated by paint weight.