Anybody got any clues? ...
Finished the body of my 16mm loco, fabricated from copper-clad PCB and brass brazing rod.
Yesterday sprayed with lead chromate primer.
Today spread with an orange paint (intended for plastics, but the hobby shop assured me it would be OK) and as soon as the orange hit the primer, the whole thing bubbled up into hideous wrinkles.
Took me 2 hours of swabbing and sanding to get the whole mess off