Unlike wood, nonporous surfaces, such as plastic and vinyl, must be abraded with sandpaper before any paint will stick to them. Metallic surface have the same problem, except they cannot be abraded with friction techniques. If you plan to paint stainless steel, you will need to prepare the surface by applying a special kind of primer that will score the surface. You will also need to take special steps to remove any surface residue that could interfere with adhesion.
Scrub the stainless steel using a water-based degreaser and a coarse plastic brush.
Rinse the steel with a water hose if you are working outdoors. Rinse with wet rags if you are working indoors. Allow the steel to dry.
Protect flooring by covering it with a fabric dust sheet. Cover any parts of the stainless steel you don't want painted with tape.
Apply a thin coat of etching primer to the stainless steel. Apply in intermittent, short spurts. Do not apply in a long, steady stream as this generally leads to sagging in the final finish.
Allow the etching primer to cure for four hours before you apply any paint to the surface.
Stainless steel is often galvanised to prevent rust. This leaves an oily residue on the surface that must be removed before applying paint. Only a water-based degreaser can remove this oil. Never use soap in place of a degreasing agent or you will not be able to get the paint to stick.
Do not attempt to use an ordinary bonding primer in place of an etching primer or the finish will peel away relatively soon after application.