IS 1477 Part 1 : 1982Methods of sampling and test for varnishes and lacquers: Part 1 General

IS 1477 Part 1:1982 — code of practice for painting of ferrous metals in buildings: Part 1 pre-treatment — governs *surface preparation and priming* of steel/iron before painting (Part 2 covers the painting itself). It is the workmanship code behind the 'painting of steel' item: the part that actually determines whether a paint system lasts.

It is read with the protective-coating stack:

• IS 1477 Part 2 — painting (application of finishing coats)
• IS 101 — methods of test for paints (acceptance of the products)
• IS 2074 — red-oxide zinc-chrome priming · IS 2932 / IS 2933 — synthetic enamels (finish)
• IS 800 — steel construction (corrosion-protection requirement) · IS 2629 — galvanizing (the alternative)

Paint adhesion and life are determined almost entirely by what's under the paint. IS 1477 Part 1 fixes:

• Cleaning standard: remove mill scale, rust, oil/grease, old loose paint and contaminants. Surface-preparation grades range from hand/power-tool cleaning (St 2/St 3) to abrasive blast cleaning (Sa 2½/Sa 3) for severe exposure — blast cleaning gives the durable bond
• Profile (anchor pattern): blast-cleaned steel needs the right surface roughness for primer keying
• Priming immediately after preparation: cleaned steel must be primed *before flash rusting* (often within hours) — a delay re-rusts and voids the preparation
• Primer selection matched to the environment and the finishing system (e.g. red-oxide-zinc-chrome IS 2074, zinc-rich, etch primer)

The rule that matters: no paint system is better than its surface preparation — a premium topcoat over mill scale fails in a season.

Scenario: structural steel for a moderately-exposed building, paint to IS 1477.

Step 1 — preparation (Part 1): for the exposure, specify Sa 2½ blast cleaning to a stated visual standard + profile; degrease first if oily.

Step 2 — prime immediately: apply the primer (e.g. IS 2074 red-oxide-zinc-chrome, or zinc-rich for harsher exposure) before flash rust — same shift as blasting.

Step 3 — build system (Part 2): primer → undercoat → finishing enamel (IS 2932) at specified dry-film thickness per coat, respecting recoat intervals.

Step 4 — DFT check: measure dry-film thickness; the *system* DFT (e.g. ~125–175 µm total) is the durability driver.

Step 5 — accept: preparation grade witnessed before priming (it can't be checked after); products accepted to IS 101. The preparation is the part you can never inspect once it's painted — so witness it.

1. Painting over mill scale / rust / a contaminated surface. The defining failure — the system peels regardless of paint quality. Preparation grade is non-negotiable.

2. Delay between preparation and priming. Blast-cleaned steel flash-rusts within hours; priming the next day voids the whole preparation.

3. Specifying the finish but not the preparation grade. 'Two coats enamel' with no Sa/St grade lets the contractor wire-brush and paint — guaranteed early failure.

4. Ignoring dry-film thickness. Corrosion protection is a DFT-and-system property; thin/missed coats fail at edges and welds first.

5. No witness of preparation. Surface prep is invisible after painting — if it isn't witnessed/recorded before priming, you have no evidence and no recourse.

• IS 1477 Part 2 — painting of ferrous metals (application of coats)
• IS 101 — methods of sampling & test for paints/enamels
• IS 2074 — ready-mixed red-oxide zinc-chrome priming
• IS 2932 / IS 2933 — synthetic enamels (finishing)
• IS 2629 / IS 4759 — hot-dip galvanizing (alternative protection)
• IS 800 — steel construction (durability/corrosion clause)

IS 1477 Part 1 is old and reaffirmed; international practice references the ISO 8501/8502/8503 preparation-grade and ISO 12944 protective-coating-system framework, which large EPC specs now cite alongside IS 1477 — compatible in intent and acceptable when cross-referenced. Whatever the citation, the engineering truth is fixed: surface preparation, not paint brand, decides coating life.

The practitioner contract: specify the preparation grade (Sa/St) and primer explicitly, prime immediately after preparation, define the system DFT, accept products to IS 101, and witness/record the prepared surface before it disappears under primer. For aggressive/coastal steel, hot-dip galvanizing (IS 2629) or a duplex system usually beats paint-only — but if paint is used, IS 1477 Part 1 is where the durability is won or lost, every time.