Question For Painters - Flexible Part

[MAMBA]

I am getting ready to paint the front fascia of my black 95 RT/10. I'm using House of Kolor KS11 Ko-Seal black primer sealer, PPG DBC 9874 black basecoat and PPG 2021 Clear. I know a flex additive needs to be added to the clear but is not required for the DBC basecoat. What I'm wondering is does it need to be added to the primer sealer? I wouldn't think so but not sure.
I'm using the HOK black primer/sealer because I have some left over and I used it when I painted my motorcycle with the PPG DBC basecoat. There were no compatibility problems between the two and it worked very well. The guy at my local auto paint store also said there would be no compatability problem. I have painted quite a few parts but never a flexible part so I just want to make sure.
Thanks for any help you may be able to offer.

 

[SNKEBIT]

just put it in the clear

wifey uses that stuff all the time!!!!

 

[Lee00blacksilverGTS]

Make sure you check with your paint supplier. I have painted a bunch of Vettes. I always was advised to use the flexible agent in the primer, and the color and clear coats. And the results last a long time. All the spiderwebbing you see on the rubber bumpers of 73 and up Corvettes comes from not using that stuff, can't see how it would hurt to add some in to everything you shoot. I always adjusted my air pressures up a little bit when adding this stuff just on a general assumption it might flow a little thicker and I paid particular attention to running thinner through the lines after using it.