Does a urethane BC/CC system need an additional flex agent?

Someone told me that urethanes do not need a flex agent because they are flexible by nature. Not sure what to believe.

Can someone shed some light on this for me?

 

Not needed. Also modern clears are very flexable too. Even on plastic bumpers I don't use it. Paint holds up very good and I paint bumpers off the car and never had any issues after installing it.

 

I always see cars with aftermarket paint jobs start to crack and flake off of the bumpers.

Could this be because they are not using urethane paint? and/or poor surface prep?

Thanks for the response.

 

i didnt add flex into my ppg clear and havent had any problems and my bumpers have come off several times since then without chipping.

 

Flex agent is mostly needed in anything that is plastic.Every notice when you're at a body shop mixing primer, and the machine says add (estimating 20%)flex additive to the primer,when doing a plastic bumper?That keeps the paint from chipping on plastic parts.Even Glasurit makes a clear called 109 has flex additive built in and it lays out flat!!I seen tons of people mix there clear,hardner,reducer,and add flex additive.And lay out the whole car with it.Bet most people don't know that bulldog flex agent can be mixed in your clear!!! Grab a can,and read for yourself if you think this statement is flase.

 

Poor preparation makes or breaks the life of the paint job,Regardless if it's urethane or not.

 

So are you saying that adding flex agent is essentially cheap insurance?

how about in the primer? Is it not needed?

 

bull dog is the ISH..... you could spray it on bare plastic and makes paint stick like no other.