[Gearhead55]

Spray this on the plastic before you paint.

 

[Gearhead55]

TJV55: I notice the PPG label on the adhesion promoter you show.. I stopped by my PPG store a few days ago and they recommended/sold me the Bulldog adhesion promoter (for the plastic, and he also said it would be good for the aluminum also?)...

Astroracer: I've used a hot water pressure washer on it twice (after gunking/brushing it), so the aluminum is clean, but discolored (59K miles on the 15 yr old LS1 engine/trans).. so I want to renew it and color it. I prefer to paint it than to 'acid wash' it as it will just discolor again ... I really like what you did with your coil pack cover and plenum/intake.. Is that red the same as your car color? My car is red also, firewall/innerfenders/etc... so I've been thinking 'contrast'.. either silver or black.. currently leaning towards argent silver. PS. I've always used a 'zinc chromate' type paint on aluminum before painting (same/similar to self etching primer I think), but the paint guy at PPG suggested just cleaning and priming with epoxy primer? He suggested priming the plastic with epoxy primer as well (after cleaning and using the bulldog promoter..)..

thanks to all of you who replied.. gives me some stuff to think about and makes me think if I clean it will probably be good regardless of what else I do..

I would use what your PPG store recommends. This is what they recommended to me- but 2 years ago. I did base coat clear coat on my plastic with this.