Hum...This is a really helpful comment from you cyclopsblown. But frustrating at the same time.
Let me resume, If I use epoxy primer as a layer under my base coat, I must not sand it with a grid finer than 80 grid because my base coat will not really stick to it.
So, I have to put 2k high build primer over it anyway to be able to gain a smooth finish for my base coat.
Whatever I do, I must buy a 2k primer to put in between the bondo and the base coat.
This might be my last question. Which Dupont 2k primer would be compatible to stick to bondo and ChromaBase base coat?