Painting work on metal surfaces

Painting on metal surfaces (iron and steel)

1. Cleaning: remove rust, scale, oil and grease by scraping, wire brushing, sandpapering, or by a solvent wash or sand blasting.
2. Priming coat: soon after cleaning, apply a red oxide or zinc chromate primer by brush in one or two coats to prevent rusting. Allow 24 hours to dry.
3. Stopping: fill dents and holes with putty and sand it smooth.
4. Second coat (undercoat): apply an undercoat of enamel or oil paint. Let it dry and rub it down lightly.
5. Finishing coat: apply one or two coats of enamel or synthetic paint of the required colour, with 24 hours between coats.

Precautions: work in dry weather, do not paint a wet surface, and use primer and finish of the same make.

Painting on masonry (plastered) surfaces

1. Surface preparation: the plaster must be at least 3-4 weeks old and dry. Remove dust, grease and efflorescence with a wire brush, and fill cracks with putty.
2. Priming: apply an alkali-resistant primer or cement primer.
3. Putty: apply wall putty in 2 coats, rubbing with sandpaper after each.
4. Painting: apply two coats of emulsion, distemper or cement paint with a brush or roller, leaving 4-6 hours between coats.
5. Cement paint: the surface is wetted before application and cured afterwards.