i tried krylon h20 paint and a couple others someone told me duplicolor plastic fusion will work but i dont want to waste money trying another useless thing again
before you can paint a raw plastic part you must first wash it with alcohol, then take a gray Scotchbrite pad and wet it with alcohol while you sand the part with it. next wipe it down with alcohol again and then spray it with a plastic parts adhesion promoter (available in a spray can at any parts store) and then after that any paint should work. when painting plastic or rubber parts, proper preperation is the only way to make paint stick.
I'm an engineer an polymers are hard to stick things to. If you notice in the glue section in your store, the glues will say sticks to "some" plastics so good luck