Remove rust to keep new paint from flaking off.
Rusted metal not only looks bad, but also it eats at viable metal, corroding it more and more until the structural integrity of the object is compromised. Left untreated for a long time, holes form in rusted metal. Covering the metal with a layer of fresh layer of paint prevents rust from returning for a long time, but before you can paint rusted metal, you need to prepare the surface. Painting rusted metal always involves several steps, but spraying techniques can be utilized to make the process faster and easier.
Instructions
1. Place tarp or plastic sheeting underneath the object being painted. Cover any surfaces you don't want sanded or painted with painter's tape.
2. Sandblast the object for the quickest results. Attach the sandblaster to an air compressor, then power them both on. Spray the metal object using smooth, even strokes to remove the rust and obtain an even finish.
3. Scrape any loose paint and rust off the metal if using a sandblaster isn't an option. Scour the surface of the metal with a wire brush afterward. Complete rust removal is not necessary to paint the metal.
4. Rinse the metal off after the roughing up the surface. Spray the object with a hose, or wipe the rust, metal and paint residues with a damp rag. Dry the object after cleaning.
5. Spray a coat of zinc chromate-based primer on the metal. Cover the surface evenly, applying the spray with smooth, consistent strokes. Allow the primer to dry.
6. Spray the metal with a high-quality enamel paint made for exterior use. Coat the metal smoothly and evenly. Allow the spray paint to dry.
7. Inspect the quality of the first coat of paint. Apply a second coat if necessary. If more than two coats are needed to obtain a clean painted finish, allow the paint to dry completely before adding each subsequent coat.
