Hi MF,
Hammertone was designed to spray over cast metal (iron, steel and Ally) which generally had a finished surface full of imperfections and with the way the paint cures out it pretty much has the ability to hide a multitude of sins underneath it. As such most machinery which was made up of castings was painted with Hammertone.
You can most certainly spray it over existing painted surfaces but surface prep must be done just like any other paint requires for adhesion.
Debbie is the person to speak to at Ultra Color, but don't expect miracles that's for sure.
Cheers,
BB.
