I am painting may car.

I would prefer to paint the front and rear bumper covers off the car before putting them on.

This is a race car so none of the usually BS constraints are in place. No head lights, fender liners, or any other factors to get in the way.

I put the nose on and aligned it in about 10 min. Rear goes on in 5 min. These times did not include the plastic rivits. All parts will be test fitted prior to final paint and assembly.

If I paint it with flex agent, how long do I have to install it and how much twisting will it take?

Also do I need to prime the bumper cover which is a factory black primer to cover with blue paint. If I do not prime, I would water sand with 400 to 600 grit.

My thought are if I use primer I will have to add flex too and the flex may be flexed out by the time I add color.

Bottom line I do not want the paint to crack when I put the bumper covers back on.

 

add flex agent to the color. that will keep the paint from cracking. make sure its compatible with the paint though.

 

My real question is...

How long does the flex agent last? Can I wait a year to put the bumper cover back on?

I was under the impression that the flex agent only lasts a short period of time so parts need to be on the car or installed quickly to minimize the flexing of the part before the flex agent burns off.

 

no, the flex agent stays on the paint and primer. so it will last the same period of time the paint does because its mixed together so yes you can wait a year with no problem as long as your prep work is done right and you use a decent paint and clear..