Well sort of a body kit..i'm putting an LS sport ground effects kit on my cavalier and i had to sand all the paint off, i got them all primed and ready for paint..now i hear i have to use a special primer for them because the paint will crack if the bumper is hit...
any truth to this..
Or should i be able to get by with the regular primer?

just add some flexible agent to the paint and you should be fine.

Odds are if you're hit your paint will crack irregardless of what paint you use or what you add to it.... LIGHT hits you'll be fine... just add some flex additive to your paint

let me just clear it up for ya dude
flex agent is not to be used in primer or in base coat
sealer can be flexed clear coat can be flexed
at least in ppg it is
if the bumper is preped correctly and all products mixed correctly you should have no problem`s at all

can i haz bondo

When I painted my Streetfire urethane bumper, RK Sport's directions said to include a flex additive in the primer ( you can by flex primer from the auto paint supply store) and use a flex agent in the paint.

wrong......ppg makes a plastic primer made for plastic and the ncs sealer can be flexed
base coat should never be flexed clear coat can be flexed
2021 ratio; 4;1;2;2
2042 ratio 4:1:2:2
ncs 2004 2005 sealer ratio: 3:1: 1/2 flex agent
and ppg`s ncp 271 ratio 3:1 when it first came out ppg said you can add color to it and reduce it to make it a sealer then they tested it more and came back only with using it as a primer
every system out there makes a specific product for a specific use this isn`t like let`s play mad scientist ratio`s are there for a reason
follow them

can i haz bondo