| Epoxy | Steel structures, tanks, machinery, pipelines, marine interiors and industrial floors | 75–200 μm | 45–80% | Approximately 250–450 g/L, depending on formulation and local regulations | Excellent when applied over suitable preparation and used in a complete coating system | Fair to good; may chalk or lose gloss during prolonged direct sunlight exposure | Approximately 90–120°C | Strong adhesion, chemical resistance, abrasion resistance and barrier protection | Limited long-term exterior color and gloss retention; sensitive to moisture and low temperatures during curing | Check surface-preparation requirements, curing temperature, recoat interval and compliance with local VOC limits |
| Polyurethane | Exterior steel, infrastructure, transport equipment, exposed industrial assets and topcoats over epoxy | 50–100 μm | 45–70% | Approximately 250–450 g/L, depending on solvent and waterborne technology | Very good when used as part of a compatible primer and intermediate-coat system | Excellent resistance to sunlight, gloss loss and color fading compared with many conventional coatings | Approximately 80–120°C | Good weathering, abrasion and chemical resistance with attractive long-term appearance | Application can be sensitive to humidity; some two-component products require strict handling controls | Verify isocyanate-related safety requirements, humidity limits, pot life, local worker-protection rules and VOC classification |
| Zinc-Rich Epoxy | Steel bridges, offshore structures, storage tanks, heavy equipment and atmospheric corrosion-control primers | 50–100 μm | 50–75% | Approximately 250–450 g/L; waterborne and low-VOC versions may be available | Good as a primer; normally requires a compatible protective topcoat for long-term UV exposure | Low as a standalone finish; the surface may chalk and should generally be overcoated | Approximately 100–150°C, subject to the product system and exposure conditions | Provides sacrificial and barrier protection when correctly applied to properly prepared steel | Requires strict surface cleanliness, correct zinc loading and careful control of dry-film thickness; unsuitable for every substrate | Confirm zinc-content method, applicable corrosion category, compatibility with subsequent coats and regional environmental restrictions |
| Acrylic | Exterior metal, general industrial equipment, infrastructure, masonry and maintenance applications | 40–100 μm | 35–65% | Approximately 100–350 g/L; waterborne products can be substantially lower | Good for moderate environments when used over an appropriate primer | Very good color and gloss retention in many exterior applications | Approximately 60–90°C | Fast drying, good weathering performance, broad color availability and relatively easy maintenance | Generally lower chemical, solvent and immersion resistance than epoxy systems | Compare waterborne or solventborne classification, minimum application temperature, humidity limits and regional VOC thresholds |
| Alkyd | General maintenance, agricultural equipment, indoor machinery and low-to-moderate exposure steelwork | 40–80 μm | 40–60% | Approximately 300–500 g/L, subject to formulation and jurisdiction | Fair to good in mild or controlled environments with suitable priming | Good initial appearance; long-term gloss and color stability are usually below polyurethane performance | Approximately 60–80°C | Easy application, good flow, broad availability and relatively simple maintenance procedures | Lower resistance to strong chemicals, solvents, continuous immersion and severe corrosion exposure | Check compatibility with zinc-rich and epoxy layers, drying performance in humid climates and restrictions on higher-VOC products |
| High-Solid or Waterborne Industrial Coating | Projects seeking reduced solvent emissions, industrial maintenance, buildings, equipment and infrastructure | 60–150 μm | 55–85% for high-solid systems; waterborne systems vary widely | Often approximately 50–300 g/L, but the legal limit depends on product category and market | Good to excellent, depending on resin chemistry, film build and system design | Good to excellent, depending on whether the binder is acrylic, epoxy, polyurethane or another technology | Approximately 60–120°C, depending on resin chemistry | Lower solvent emissions, higher productivity potential and better alignment with increasingly strict environmental rules | Drying and curing may be affected by temperature, humidity, ventilation and substrate conditions | Request technical data sheets, safety data sheets, VOC test method, legal VOC category and transport classification for the destination market |
| Data note: The figures are representative industry ranges for comparison and are not universal specifications. Actual performance depends on resin chemistry, pigment loading, surface preparation, application method, coating-system design, climate, exposure category and local regulations. For project approval, compare the product technical data sheet with applicable standards such as ISO 12944, ISO 8501, ISO 19840, ASTM D7091 and the relevant national VOC requirements. |