How to make plastic pieces look smooth?

[Race94]

I want to paint my radio bezel and a few other parts in the car, thing is the have this crumbled/rocky stock look, how would i go about to make them smooth and paint them?

 

['96_Talon_TSi]

Its a rather time consuming project. Be prepared to spend a lot of time sanding, and some money on filler and sand paper.

Heres a step by step. I have pics of the process on my computer, but they are big, so i cant post them. If you have AIM feel free to IM me for them.

Items needed:
>filler primer (can be had at autozone,advanced, or the like)
>various fine grits of sandpaper (800, 1000, 1500)
>a sanding block
>bucket w/ water for wetsanding
>rubbing alcohol or acetone for cleaning
>some rags for wiping
>time and patience. (one of the most important things needed)

The process:

>Pull the peice out of the car (pretty obvious)
>Clean it off w/ acetone or rubbing alcohol, be sure to not touch the cleaned part with your fingers.
>Spray the peice with 3-4 medium layers of filler primer
>Get some 800 grit sandpaper and the bucket, and start wetsanding.

>sand until the grain shows through, but make sure to not take off all the filler​

>clean it again, then spray it again
>wetsand it again with 800

After you sand it this time, the grain should still show through, but should be less prevalent than before​

>clean it, and spray it again
>wetsand with 1000 grit.

the peice should be getting really smooth by now, and the gain should be gone. If its not, clean it, respray it, and sand the specific places where the grit is still showing​

>the grain should be completely gone by this point.
>You can either prime again, or jump straight to the paint.
>clean it, and spray it with paint. Probably a couple light layers.
>wetsand it with 1500, and repeat.

Repeat this process until the paint is covering the peice well.​

>Clean it, and spray it with clearcoat, a few light layers.
>when the first few layers of clear become tacky, spray it again, then wetsand it with 2000 grit.

this last wetsanding should make it super super smooth and super glossy​

I think that pretty much covers it. Feel free to PM me for pics of the process or if you have any questions.

 

[Race94]

great step by step thanks a lot
what kind of paint should i use? clear?

You mean automotive sandable primer in spray right?

 

['96_Talon_TSi]

I use all Dupli-color stuff. It seems to be the best quality (from my experience)

The primer, will be labeled "Filler primer", and has a picture of some dude sanding a fender w/ a primer spot on the can.

The paint, is just regular old Dupli-color paint. They have a ton of different colors.

Clearcoat, also made by dupli-color, has a clear cap on it. The clearcoat protects the paint from chipping, and gives it a nice glossy finish.

 

[Project2G]

For anyone else doing this, Kylon makes great paint that sticks to plastic.

 

[chico904]

Props to the above write-up. I know it might not be the best advice, but when I did mine, all I did was wipe it off, got some spraypaint and put on 2 light coats just enough to cover. I then laid down 3 heavy wet coats and it looks like glass. Followed with 1 light and 2 heavy coats of clear, and it still looks good 2 years later. Just be careful with runs while doing the wetcoats.

 

[guitarhero14]

One thing to add to the writeup is that before you spray your primer down on the plastic you should use an adhesion promoter. Bulldog is a good choice.

 

[welfle18]

well working in automotive body repair another route that you might go could be body filler if you are experienced in using it. Its not all that hard to use and one coat would probably do the trick. Again alot of sanding and patience is needed. Just a suggestion.