About 98% of my builds are done using Nothing but Duplicolor paints, even engine and interior parts. I use the filler primer with zero problems. the only time I've ever noticed "crazing", is when I haven't washed the part first good enough, or when I tried to spray Duplicolors "regular" primer over plastic. When I put down an opaque coat of filler primer, I can put anything down over it. I've been using Duplicolor since 1987. I've also noticed that the plastic in some of the Testors kits crazed on me, but I sanded it down between a few coats, and it was fine in the end, and to this day, the finish is great. Let me know in a PM if you want to talk to me more about this.......hope I did, or can help.