Things You'll Need
Spray multi-purpose stripper
A polyurethane finish adds a protective layer with an attractive sheen, suitable for many different surfaces. If you wish to remove polyurethane from painted metal, you need a strong stripping chemical that will cut through the layers of finish and enable you to remove them from the surface manually. With the correct product and a little effort, your metal surface will be free of polyurethane.
Place the plastic tarp over the ground to protect surfaces from the cleaning and stripping surface. Work in a well-ventilated area to avoid chemical fumes.
Spray the degreaser spray onto the metal surface where you will apply the stripper, covering it evenly with degreaser. Allow the degreaser to sit for about five minutes and then rinse it away with water. Dry the surface thoroughly with an old towel.
Shake the can of multi-purpose stripper for about two minutes.
Hold the can about 10 inches away from the metal surface and spray evenly to cover the surface. Allow the stripper to sit on the surface for about five minutes or until you notice blisters developing over the entire surface.
Position a paint scraper along the metal surface and move it lightly across the metal to remove the polyurethane. Wipe the removed materials from the paint scraper with paper towels as you work.
Continue scraping the surface lightly and cleaning the scraper off with the paper towels until you clean the metal completely.
Wash the metal surface with water after you finish. Dry the surface with the old towel.
Wear gloves as you work with the degreaser spray and the multi-purpose stripper spray to protect your hands from the chemicals.