Geoff Mills wrote:
I know paint technology is a complex science but I usually get away
with it. However, I've been tarting up a pair of old Wharfdale
speakers with spray paint to match the existing grey and black kit and
the finish coat is causing the underlying primer to bubble up on a
small test area.

The primer is "Plasti-kote, Projekt Paint, Primer SUPER" which I
bought from B&Q. I have also bought some Simoniz Acrylic Black as a
top coat. Neither cans give specific details about their chemical
composition but they sure enough don't like each other.

I'm hoping someone can tell me of an intermediate neutral coat I can
apply to avoid having to strip the whole lot back to stage 1.


IME bubbling is usually caused by trapped solvents in the basecoat i.e.
the surface cures and stops the carrier (water or solvent) evaporating
from the lower layer. Thinner coats are usually the answer.