At bit-tech today we have a new case mod project. Called Project KOS-MOS, it's based around a theme from the RPG Xenosaga. It includes some amazing cable wiring and some fantastic laser etching.
The first step was to key the metal work with a coarse 450 grit to give the primer something to bite into. After the first coat, I let it cure over night before attacking the primer with some 600 grit - the idea was to smooth out the primer giving a nice base for the final paint to sit on. I only sanded it very gently as to not take it back to bare metal; when I exposed the metal I stopped and reprimed it, then sanded again. This carried on until I had a coat of smooth primer that didnt have any exposed metal. I used nine layers in total for the front bezel switching to finer paper when I needed. Check it out over here.