What surface preparation is needed for a coastal (C5-M) environment?

Blast cleaning to Sa 2½ is the minimum requirement for high-durability systems. (Clause 4.3 & Table 2).

What is a typical paint system for a heavy industrial area (C5-I)?

A three-coat system such as a Zinc Silicate or Zinc Rich Epoxy Primer, an Epoxy MIO intermediate coat, and a Polyurethane top coat, with a total DFT of around 320 microns. (Table 2).

What does corrosivity category C4 mean?

C4 corresponds to a 'High' corrosivity environment, typical of industrial areas and coastal areas with moderate salinity. (Table 1).

How is paint thickness measured on site?

Using a calibrated non-destructive Dry Film Thickness (DFT) gauge. The frequency and acceptance criteria for measurements are detailed in Annex C.

IS 15152

: 2002

Anti-Corrosion Treatment for Steel Structures - Code of Practice

CurrentFrequently UsedCode of PracticeBIMMaterials Science · Painting, Coatings and Surface Finishing

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This code of practice outlines the requirements for the anti-corrosion treatment of steel structures. It details methods for surface preparation, selection of appropriate paint systems based on environmental corrosivity, procedures for paint application, and quality control through inspection and testing to ensure long-term durability.

Lays down the code of practice for various anti-corrosion treatment systems for steel structures using paints, coatings, and surface preparation.

Quick Reference Values

Minimum surface preparation for durable systemsSa 2½ as per ISO 8501-1

Maximum allowable soluble salt level< 50 mg/m² as chlorides

Typical DFT for high corrosion (C5) environment300-400 microns

Minimum surface profile for blast cleaning35-50 microns (depending on primer)

Minimum temperature for paint application10 °C and 3°C above dew point

Practical Notes

Surface preparation is the most critical factor for coating performance. Visual inspection against ISO 8501-1 comparators for Sa 2½ is essential before applying the primer.

Always consult the paint manufacturer's technical data sheet for specific properties like pot life, overcoating intervals, and curing times, as they supersede the general guidance in this standard.

Pay special attention to the DFT on edges, corners, and welds, as these areas are prone to premature failure and often require a stripe coat.