If you’re using the chemical paint stripper, apply it liberally to the affected area and let it sit for about fifteen minutes. Preferably cover it with a plastic sheet to keep the fumes down and keep the stripper from evaporating before it has a chance to work. The paint will bubble and peel when it’s ready to be scraped off. Remove the plastic and scrape it with the metal spatula/scraper. This should get it pretty close to bare metal. Wash the area where you used the stripper with water (some strippers require a neutralizer). Make sure you have bare metal at least two inches around the whole rust spot.