been rebuilding upgrading mommas 87 ss, cant find info that tells mewhat the front and rear bumper covers {facias} are made of so I can prep them for paint rest of car sanded and primered. any ideas I read somewhere its propylene plastic, but cant find that source again.any help is appreciated

 

Here is a link to the google search I did. there were a few videos about this on youtube that may be of interest. the first was with a brand knew part.
Hope this helps.
https://www.google.com/?gws_rd=ssl#q...pylene+plastic

 

Also a magnet will come in handy testing areas...