How to Prepare Steel for Paint
- 1). Remove all traces of rust before painting steel. One of the easiest ways of doing this is by blasting the surface with an inexpensive portable hand-held siphon sandblaster powered by a compressor; this method is especially useful on irregular surfaces such as cast iron patio furniture.
- 2). Work outdoors and load the sandblasting hopper with commercially available sandblasting grit, start the compressor and aim the nozzle 4 to 6 inches from the rusty metal. Press the trigger and work the sandblaster back and forth as you would a paint spray gun.
- 3). Abrade the rusted steel surface with either some 80-grit emery paper, coarse steel wool or a wire brush to remove every trace of rust. For an extra smooth finish complete the job with 120-grit emery paper.
- 4). Use an organic rust remover on large surfaces such as roofs, garage doors or corrugated iron. Apply the material liberally with a 2-inch paintbrush or 7-inch medium nap paint roller. Allow 15 minutes for the liquid to react.
- 5). Scrub down with a coarse-bristle broom. Rinse off with a garden hose fitted with a high-pressure nozzle. This material will not harm vegetation or injure your skin.
- 6). Clean the hand-prepared steel area to be painted with a rag soaked in denatured alcohol. Wipe down with a micro fiber tack cloth to remove any remaining sanding residue. This is not necessary if organic rust remover has been used.
- 7). Prime the steel surface with an aerosol can of zinc chromate self-etching metal primer. Shake the can and hold the nozzle 12 to 14 inches from the surface; spray with even, overlapping sweeps. Apply a single coat and allow an hour's drying time before handling.