Any idea on how to go about customizing ROTF Ironhide?

I never got the original mold in all black, and probably never will, so I'm taking ROTF Ironhide and making him movie-accurate color wise, because I strongly dislike the grey color that's currently on him?
The problem is, the black paint doesn't stick on well at all. I'm a newbie customizer, so I don't know exactly what I need to do to make the paint stick. I'm currently using Testors Acrylic Paints.
Any help would be much appreciated
The problem is, the black paint doesn't stick on well at all. I'm a newbie customizer, so I don't know exactly what I need to do to make the paint stick. I'm currently using Testors Acrylic Paints.
Any help would be much appreciated
