Mordant T Wash – Premium Pre-Treatment for Galvanised Steel
Ensure flawless, long-lasting paint adhesion on new or weathered galvanised iron and steel surfaces with our professional-grade Mordant T Wash (also known as T Wash). This time-tested etching solution, formulated to comply with the original British Rail “T Wash” specification as described in BS5493:1977 Table 4N, effectively prepares galvanised metal for subsequent coatings by chemically etching the zinc surface.
Key Benefits
- Dramatically improves adhesion of primers and topcoats
- Visible colour change (surface quickly darkens to black) confirms complete and effective treatment
- Suitable for both new/hot-dipped and weathered galvanised surfaces
- Acid-based formula in water-miscible organic solvents for reliable performance
Easy Application
- Prepare the surface: Remove heavy oxidation by scrubbing with water; degrease oil/grease with appropriate thinners.
- Apply evenly by brush — highly polished surfaces may require light abrasion.
- Watch the reaction: The zinc surface darkens to black within minutes.
- Rinse thoroughly with fresh water to remove residues.
- Re-apply to any areas that fail to blacken after re-preparation. No blackening indicates the surface is unsuitable for coating.
Important: Overcoat the treated (and dried) surface with a suitable metal primer within 48 hours to prevent re-contamination.
Ideal for industrial, rail, structural, and metal fabrication projects where reliable paint performance is essential. Professional use only — wear appropriate PPE (gloves, goggles) during application.