Can you paint epoxy over enamel painted metal?

I am guessing this is on the floor. This is probably a two component carbon bond coating. This means it is chemical resistant to even ketones. To recoat, you must use another epoxy or urethane mixture. To prepare the surface, it must be wet sanded with at least 220 grit water paper. After a good sanding, the surface must be cleaned with some sorta tack cloth. If you use a waxed based tack, do not press hard. This will cause transfere of the bees wax to the surface and cause poor adhesion. Anyway, get the surface clean as possible. Make sure the humidity is below 50% before coating the area. If you try to coat with humidity aboue 50%, you may get bubbles in your coating. They are caused by the coating trying to cure quicker than the moisture can escape. I hope you can use this information.