Alright, well I painted my poly urethane lip before. But rock chips from the highway caused it to start peeling like tape. But from what I forgot to do in the beginning before i painted was to scuff the lip. But anyways, i was wondering wouldn't sanding the lip down with like 1500 or 2000 grit paper make the adhesion stick better then scuffing it? But here is the steps i did the first time. used wax and grease remove to clean the lip, sprayed plastic adhesion, primer, paint/reducer, clear/hardner. And then wet sanded the orange peel. Did i do something wrong the first time besides scuffing it to cause the paint to peel like tape? And what is the correct prep for a polyurethane lip? thanks!

 

i think 1500-2000 is way too fine of a grit to use for adhesion... i know plastic is softer but i believe you're still polishing the part, not scuffing it...and you need to find a primer that will adhere to your particular type of plastic because every type of plastic uses a different type of primer

 

great results can be had by just wiping the thing down with wax and greese remover, spraying with the SEM primer filler in the can and shooting. those pieces are so smooth to start with i would only sand if you feel something rough.

 

So you guys are saying to just scuff it and then use a primer that is design to adhere the paint better?

 

use a primer designed to adhere to that particular type of plastic. and of course scuff it first....

 

for my polyurethane lip i just scuffed it with 600, primed, and painted it. paint adhered fine.