Hey, I am almost to the point of needing to start priming a foam piece that I have joint compounded over. My dilemma though is that I have noticed a few small areas that after sanding, the foam is showing a tiny bit. I am scared that if I go to use an aerosol primer on it its going to worm its way into a pinhole or somewhere that I cant see and start eating the foam inside. Was wondering if anyone has a suggestion on a good brush on primer maybe? Or a aerosol primer that wont eat foam? Any kind of help would be awesome.