Auto body repair & detailing: Urathane paint on urathane bumper cover, urethane paint, paint coat

Question
Will spraying a urethane bumper cover, (brand new part, never painted) with urethane paint, require a primer coat? It would seem that, because of the the flexibility of the paint, and the relative inflexibility of the primer, a paint coat alone would perform better. Have you ever tried this? I doubt it is recommended, but was just curious. TIA, MIke

Answer
MICHAEL......THERE IS STILL RESIDUE IN THE NEW COVER SO IT WOULD REQUIRE WASHING WITH WARM WATER AND SOAP AT LEAST 2X'S....THEN SANDED AND THEN SEALED WITH A SEALER THAT IS SORT OF LIKE PRIMER THEN YOU CAN SHOOT IT.

THERE ARE ADDITIVES THAT CAN BE ADDED TO THE PAINT MIXTURE CALLED FLEX ADDITIVES....SOME PAINT MANUFACTURES HAVE DIFFERENT MIXTURES.IF YOU APPLIED JUST PAINT THERE WOULD MOST LIKELY BE AN ADHESION ISSUE VS A FLEXIBILITY ISSUE.

GOOD LUCK...