Salt spray. Humidity. UV. Industrial chemicals. Built to resist all of it for 20+ years.
Chloride ions from sea air penetrate concrete and reach reinforcing steel. Steel corrodes, expands, and spalls the concrete from inside. A structure that should last 50 years fails in 15. This is the single biggest maintenance cost for India's coastal infrastructure.
India has over 7,500 km of coastline and hundreds of billions in coastal infrastructure. Corrosion costs Indian industry an estimated ₹4 lakh crore annually.
An impermeable epoxy barrier that blocks chlorides, moisture, and oxygen from reaching steel. Each layer has a specific function. Together they create a system qualified to ASTM B117 salt spray standard.
Total system DFT: 400–500 microns · Lifespan: 20–25 years coastal · ASTM B117 qualified
| Property | Hardex 3-Coat System | Alkyd Paint | Standard Epoxy |
|---|---|---|---|
| Salt spray resistance | ✓ ASTM B117 qualified | ✗ Fails <500 hrs | Partial |
| System DFT | 400–500 microns | 60–80 microns | 150–200 microns |
| VOC content | <50 g/L (near zero) | 300–500 g/L | 150–250 g/L |
| Lifespan coastal | 20–25 years | 2–3 years | 8–12 years |
| Cost per m² | ₹450–600 | ₹80–120 | ₹200–350 |
| Cost per year/m² | ₹22–30 | ₹30–50 (repeated) | ₹20–35 |
Mix life (pot life): 60 minutes at 25°C. Work in small batches in coastal heat. Do not apply over dew point — substrate must be min 3°C above dew point.
₹450–600/m² all-in materials. 20-year protection.
Add 30–40% for surface preparation and skilled application. Blast cleaning is critical — it accounts for 60% of system lifespan.
Blast clean steel to Sa 2.5 or grind concrete to remove laitance. Achieve 40 micron anchor profile. Remove all rust, oil, and old coating. Critical: do not paint over flash rust — apply primer same day as blast.
⏱ 8 hrs/day · Blast or grind team · Most critical step
Apply same day as surface prep — especially on steel where flash rusting begins within hours in coastal air. Even roller coverage.
⏱ 3–4 hrs · Cure: 4–6 hrs before topcoat
Mix 3:1, apply by roller in 2 passes — wet on wet. 200–250 micron WFT per coat. Check dew point before application. Pot life 60 min — work in batches.
⏱ 4–6 hrs · Cure: 8–12 hrs to recoat
Second coat builds system to 400–500 microns DFT. Check thickness with wet film gauge. System is now chloride-resistant.
⏱ 4–6 hrs · Full cure: 7 days
Apply HE400 UV topcoat if required for colour or additional UV protection. System complete. 20–25 year design life begins.
Total: 4–5 days for 500 m²
Yes. SBR-50 primer is formulated for both steel and concrete substrates. Preparation differs — steel requires blast cleaning, concrete requires laitance removal and open surface. The marine epoxy topcoats are identical for both.
Minimum 10°C substrate and ambient temperature. Maximum 40°C. In South India's peak summer, apply early morning (6–10 AM) to avoid overheating during pot life window.
Yes — hand tool cleaning (wire brush, grinder) to St 3 is acceptable. However, blast cleaning to Sa 2.5 gives 40–60% longer system life. For critical infrastructure, blast cleaning is strongly recommended.
For permanently submerged structures (jetty pilings, dock walls), use a minimum 3 coats of HE500 at 600–700 microns DFT total. Contact Hardex technical team for submerged application specifications.
Inspect annually. Look for: chalking (UV breakdown of topcoat), blistering (moisture under coating), rust spots (primer failure). Surface maintenance coat of HE400 at year 8–10 extends system life significantly without full recoat.