Hello, I'm in the process of repainting my 03 Monte Carlo SS Jeff Gordon Edition. My question is how do you prepare the front and rear bumpers? I've stripped the original paint off down to bare metal on the car body but these are made of plastic. Any help would be greatly appreciated.

 

You'll want to sand the plastic bumpers down so that the paint has something to stick to. Clean with degreaser or denatured alcohol and use a primer sealer. Once your coats of primer sealer dries, use your coats of paint and polish.

 

The first (2 part) question is - why did you strip the body to bare metal? Are you trying to accomplish the same with the bumpers? I'm just asking because it's fairly unusual to strip factory paint ALL the way off as its hard to beat the adhesion of the factory primer layer.

If you are trying to strip the bumpers totally bare, the process is really no different than the rest of the car was - you just can't be quite as aggressive as the substrate is softer / more prone to grit gouging. Not sure if you're blasting or sheet sanding, but for sheet sanding, I'd start in the 200s to see how that does. Just start on one area and take it down as far as you're shooting for. You can adjust from there after you see how it comes out. Best practice is always to do a strong degreaser before you start sanding any of it. You really don't want to get any remnant wax / road grime ground into the plastic as the base material is much more picky about what solvents it can handle than metal is.


As for prep, it depends how deep you go with the sanding. If going totally bare, you need to do an adhesion promoter before priming to make sure it sticks. You'll want to follow the instructions for the adhesion promoter as to what grit to prep with. There's also a plastic bumper specific filler thats made for use in (semi) flexible applications.

Depending which paint/primer system you use, you may need flex additive.

 

Thank you

 

I am completely restoring my car. I knew the bumpers were plastic but i didnt think about that when i took thr paint off. I used the Coopers Paint stripper from Australia. Let me say one thing, that stuff works REALLY good. Once I sprayed it on the bumpers I couldn't stop it from taking everything off. I figured it would need some adhesion promotor. I'm hoping the Eastwood Roll On Primer will work.

 

Why roll on primer - you do have a spray gun for the paint work, right? That stuff is for a person trying to hobble by in their garage to get through the bodywork stage because they dont have a gun/compressor. Youre not going to find pro shops rolling coats on. Given the extreme amount of effort youre going to - skip the hobbyist grade stuff and use pro products (especially for arguably the most important layer that holds everything together).