To paint over ANY surface, without sanding, use a product called 'ESP Easy Surface Prep', available at hardware and paint shops. Wipe on, wipe off and paint in 90 minutes. Works well over enamel paint , without having to sand. SAVES HOURS of work. It was recommended to me by a professional painter.
Took an old smelly couch, stripped it and made it into an outdoor couch. I used fence pickets, sanded them smooth, stained and attached to front back and sides. I used premium quality pine for the arms and top. Total cost, roughly 150 dollars. Still needs cushions and pillows... anyone want to sew some for me?? Reuse, Recycle.