Short term-wash-n-wax. Long term-sand down to bare metal or close to that. Use a Sherwin Willians industrial enamel and it will be good for 7-10 years. You can also use a siliconized oil based paint( reasonable price compares to 1K or 2K). High gloss and long gloss retention. Very durable. You need to spray or roll it in a garage. Takes 8-10 hours to set.