Dave,

It can happen. I sprayed the Swee' Pea fuselage, Swee' Pea tail, Stinger fuselage and Smasher tail with epoxy primer. The Swee' Pea tail stuck and the Stinger fuselage stuck. Exactly the same preparation, and the same batch of primer.

I somewhat determined that the Frekote had expired and failed. But I couldn't figure out why some stuck and others didn't. The only thing I could figure is that the Frekote had actually stopped working, and I was getting good pulls because of existing wax.

If you did anything different to one side, it could have affected the side that stuck. If you used different paint on the two sides, even if it was the part before, it could have made the difference.

It is a shock when it happens. I was using 100 PSI air and a part just would budge. When I used a rubber mallet, I could usually tell when the part released, but not this time. It has me very jittery now.