What would be the best way to remove spray paint from Urethane bumper Covers and Ground effects. I want to paint these parts but want to get rid of all the cracking crap to start fresh (with a flex agent!)

 

Really...Hand Sanding, Laquer Thinner, DA? nothing...

 

I think someone makes an aircraft stripper that is specifically for plastic and urethane. Would like to know the answer to this too as I need to strip my hood vents and regular aircraft stripper does nothing. I want to say Pep Boys carried it like 6-7 years ago (bulldog brand maybe?), but have not seen it anywhere since then.

 

Da 220 grit, with 220 you will have to prime to get out the scratches. Make sure to keep edges and line sharp when sanding. Then block sand. Flex agents were generally for older paint formulations (there may be lesser paints that still need them), PPG and RM do not require flex agent.

 

at homedepot they have graffiti remover that works great it did not damage urethane bumper on my sisters car

 

Are you trying to strip it to bare bumper??
If so, Im a fan of soda blasting the parts.

If your trying to take off spray paint over spray I use carb and choke cleaner sprayed on a rag then wipe away..

 

I believe that his real issue is with the base/clear coat cracking and that the spray paint was added as a quick fix. In order to fix this it must be taken down past the damage, probably as far down as the primer or the plastic itself. Soda blasting is the way to go, but a luxury for some (like me). We are overthinking this, either soda, or sand past the damage.

 

The bumper was spray painted over whatever waas there but it is cracking and the wrong color. I want to strip the bumper in order to repaint it the right color and properly and have it look good. If that means sanding down to bare platic then so be it.