Oil-based paints are the traditional choice of furniture craftsman for hundreds of years. Before painting on furniture you should clean it. Paint cannot stick to an item that is dirty so clean furniture and let it dry complete. Next you will need to sand down your piece with 120 grit sand paper, removing any rust from the piece. Sanding will give the paint something to grip to. It will helps as do not last paint. Once you are done priming your piece of furniture, it is time to prime it. Like sanding, primer helps the paint to stick better to your furniture, so take the time to apply a few light coats of primer before you paint.
Once your primer has had time to completely dry, you can apply your paint. Typically spray paint has the smoothest results on metal, however if you apply your paint correctly you can get good results with a brush as well. Either way, you want to apply your paint in several light coats, letting dry between each coat. This will help prevent drips and give a smoother finish. If you do choose a spray paint, look to see if you can find one specifically designed for metal. These paints will typically protect your furniture from rust for years to come, so they are worth the extra money. Brands like Rust-Olium and Krylon both provide excellent results at a reasonable price.

Here is a link that might be useful: Metal furniture painting

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