WH42-25 Marine Waterborne Epoxy Finish

WH42-25 Marine Waterborne Epoxy Finish

Product Introduction:

WH42-25 is a two‑pack waterborne epoxy finish formulated for the protective and decorative coating of steel structures in above‑water marine and atmospheric environments. As a low‑VOC coating (less than 80 g/L), it offers an environmentally responsible alternative to conventional solvent‑borne epoxies, without sacrificing corrosion resistance or appearance. The product provides a glossy, durable finish that exhibits excellent adhesion to properly prepared primer surfaces. Its water‑based chemistry significantly reduces solvent emissions, simplifies handling, and enables easy clean‑up with water, making it particularly suitable for use in environmentally sensitive areas and modern shipyards. WH42-25 is available in a wide range of colours to meet aesthetic and identification requirements.

WH42-25 has a volume solids content of 50% ± 2% and dries to a high‑gloss finish. The two‑pack waterborne epoxy chemistry provides robust protection against atmospheric corrosion, forming a tough, durable film that resists moisture, chemicals, and mechanical damage. It offers good recoatability with compatible primers and topcoats, and exhibits excellent colour retention when exposed to typical marine atmospheric conditions.

Intended Uses:

This finish is designed for steel structure anticorrosion in atmospheric environments and for use in all above‑water areas of ships and marine structures. It is suitable for newbuilding construction, as well as for maintenance, repair, and on‑board touch‑up operations.

Mixing And Application:

The product is supplied with a mix ratio of 3.9:1 by volume (5:1 by mass). No induction period is required. For large‑scale work, airless spray is recommended, using a tip size of 0.38–0.53 mm and an output pressure of at least 15 MPa. Air spraying is also suitable, with a tip size of 2.0–3.0 mm and a minimum pressure of 0.4 MPa. Brush or roller application is acceptable, though multiple coats may be needed to achieve the specified film thickness. Thinner (water) is generally not recommended; if absolutely necessary, it should not exceed 5% of the total volume. Equipment cleaning should be done with water.

Film Thickness & Theoretical Coverage:

Drying & Overcoating Data：

Surface Preparation:

All surfaces to be coated must be cleaned with high‑pressure fresh water or fresh water washing, and all oil, grease, soluble contaminants, and other foreign matter must be removed in accordance with SSPC‑SP1 solvent cleaning. Surfaces should be clean, dry, and free from contamination. WH42-25 should be applied over a recommended primer coating system. The primer surface must be clean and dry, and WH42-25 must be applied within the specified overcoating intervals (consult the relevant primer data sheet). Areas of breakdown or damage should be prepared to the specified standard (e.g., St3) and primed before applying WH42-25. For repair work, WH42-25 may be applied directly over aged WH42-25 coatings, provided the existing coating is intact and firmly adhering. Loose or flaking coatings should be removed back to a firm edge, and the area should be thoroughly fresh‑water washed, degreased, and repaired with WH42-25 or an appropriate primer before the full coat is applied.

Application Limitations:

The suitable application temperature range for WH42-25 is 5°C to 35°C. Application should only proceed when relative humidity is below 80% and the substrate temperature is at least 3°C above the dew point. In poorly ventilated areas, forced ventilation for at least 8 hours is required. Do not walk on or contaminate the coated surface, and do not apply subsequent coats until the film is hard dry. Protect the product from freezing at all times during storage and transport. Avoid prolonged inhalation of solvent vapours and paint mist, and prevent skin/eye contact. Adequate ventilation and fire precautions must be maintained during use.

Storage And Packaging:

Store in a cool, dry, well‑ventilated area, away from direct sunlight, heat sources, and open flames. Containers must remain tightly closed. Protect from rain during storage and transport. Shelf life is a minimum of 12 months at 25°C (subject to re‑inspection). Packaging: Part A – 22.7 kg / 15.5 L in a 20 L container; Part B – 4.3 kg / 4.5 L in a 6 L container. Flash point for Part A, Part B, and the mixed paint is all above 101°C.