Whatever means you use to roughen or etch the surface it's absolutely mandatory that the surface be super clean before paint is applied. I like to use CRC Brake Cleaner. It's good stuff, dries without leaving a film & it's really strong stuff. If you use it I'd advise you to wear rubber gloves & good eye protection. You can get it at most NAPA auto parts stores. If it were me I'd call some local machine shops & see if they do glass bead work. Just a thought.
Good luck
Bushwack
Good luck
Bushwack
