Steel is an alloy of iron and other metals, such as manganese and tungsten. Steel resists oxidation better than iron, but over time it oxidizes anyway. Due to exposure to oxygen, the iron contained in the alloy slowly oxidizes, turning into iron oxide, commonly called rust. You can embellish rusty steel by painting it, but you must thoroughly clean and prepare the surface before painting. Read here to find out how.
Steps
Step 1. Scrub the rust off with a wire brush
You can use a hand brush or an electric drill equipped with a rotary mushroom or disc brush.
If you need to treat a large area, use a sandblaster to remove the rust. The sandblaster is a machine that removes rust by means of a jet of compressed air containing abrasive particles
Step 2. Carefully wipe the surface with 80-grit sandpaper, then go over it again with 120-grit sandpaper, finer
Once this is done, sweep your work area well to prevent loose particles from sticking to the surface during the painting phase.
Step 3. Clean the surface with a degreasing product
Cleaning products based on pine or citrus extracts may be fine. Scrub well with a rough brush and rinse with clean water.
Step 4. Dampen a rag with paint remover and wipe the surface of the steel
This step is to remove the slightly rusty appearance that remains after the cleaning phase.
Step 5. Lay the steel artifact to be painted on a protective sheet, or protect the surrounding area with sheets, so as not to dirty with the paint
Step 6. Brush the metal with a rust inhibitor (usually zinc or iron oxide based)
Allow the rust inhibitor to dry respecting the times indicated in the instructions for the product used. Apply a second coat if suggested by the instructions.
- Do not use spray painting techniques to give the rust inhibitor, as this would prevent the product from penetrating the microscopic pores on the metal surface. This is even more important than for the final paint, because the rust inhibitor's job is to inhibit the oxidation process over time.
- You can also apply a coat of rust resistant enamel on top of a first coat of regular rust remover.
Step 7. Paint the surface of the steel with two coats of paint
Since steel is usually intended for outdoor use, use exterior paint. For the type of finish, matte, semi-gloss or gloss, follow your tastes.
- Use a paintbrush or roller to apply the exterior paint if you want to make sure you get to every crevice. Keep the brush close to the neckline for better movement control.
- Use spray paint to get an even surface appearance. Keep the sprayer at the right distance, according to the manufacturer's instructions. Spray the paint parallel to the object to be painted, with smooth back and forth movements. You will get a professional looking finish, avoiding the formation of drops on the surface.
Advice
- If you used rust remover or oil-based polish, the finish paint should also be oil-based. Use water-based paints instead if you've used water-based rust remover.
- You can also use a rust converter to prepare the steel, instead of removing the rust with the wire brush. Rust converters are products that transform rust into an inert material through chemical reactions. This is a good choice for finely decorated surfaces, but remember that with this process you could get to coat the metal with a rather thick and rough cured layer.
- If you want a highly professional result, with a perfectly glossy finish, after removing the rust, apply special putty for body shops. This is fine, for example, for doors or bicycles if you want them to have a smooth and shiny look.
