plastic prep

plastic prep help!
Im determined to paint my 87 fiero gt! This has been a four year project that helps me keep my sanity while Im not floating around on a ship , considering that I'm 7 years into a 20 year Navy career. Ive already got over 12k, including a v8 installation, in this project. I know this is not alot of $ relatively speaking, but its alot for me, and painting my car is one of my most important goals. Quickly, the fiero is constructed of entirely plastic body panels. The paint on the car is original which is a plus, no 2nd and 3rd repaints to deal with, but, the clear coat is completely disentegrated. As I sand the clear coat, Ive noticed that even when I sand it completely smooth with fine sandpaper, it can still be scratched etched with a fingernail. My first thought is that since it can still be scratched with such ease, Im going to have to take it completely off? When doing so with a broad palm sander, eventually the sanding reveals some of the bare plastic material in places. I am hoping to use a kirker brand paint system Ultra Glo Acrylic Urethane which comes with a Perfect Prime 2K Urethane Primer. These are my questions.

1. Do I need to completly remove this apparently disentegrated clear coat
2. If I do so, and bare plastic is revealed, will the primer work directly or, do I
need to spray an adhesive promoter sealer, and what kind, type?
3. Once 1 and 2 are solved, and primer is applied should the primer be
sanded, or will I have similar results if the acrylic/clear is sprayed within
time frames alotted based on the primer specs.

Look, any help is greatly appreciated! If you have no experience with this brand, thats fine, lets assume this is a typical paint system. If you would like to recommend what you would do with the paint system you use, please do so, Im not firmly committed to any particular paint.

Any help is greatly appreciated
Thanks, Hank
Proud Citizen and Server of the Greatest Country on Earth

Hi Hank

With any paint job preparation is the key. I would take it back to bare Plastic, this way there is nothing to fail later and wreck your paint work. There are plastic primers around, but it is best to use a paint system from one company, this would include primer, sealer, base coat, clear coat, reducers etc. By using the one paint system you are assured that the various products are compatible, which is important for adhesion, longevity and final finish.

Hope this helps
Justin

Use the DuPont Adhesion Promotor, too. Makes the paint stick a lot better. Might want to try the DuPont Vinyl Dye, it works on plastic.

Hank,
Painting a Carbon Fiber substrate is just like painting fiberglass.
Scuff it down to a feather edge, and prime it, wet sand it , and seal it, wet sand it again, let set for 48 hours to 72 hours before proceding, wash and paint.

The only thing I treat special is vinyl type plastics, such as on a "quad". I then use a plastic adhesion promotor/crosslinker/flex agent called "Bull Dog".

Every other plastic simply gets washed, sanded, washed, and primed with urethane primer. No problems.