Morgans wrote:


"Richard Riley" wrote

My Long
EZ had acrylic enamel over an unknown dark grey primer (circa 1989, it
wasn't lacquer based but I'm not sure what it was) - when I went to
strip the paint the topcoat peeled off in large sheets, it hadn't
bonded to the primer at all. I don't know what the failure was, it
might have been either the primer or the topcoat. So I'm strictly a
Linear Polyurethane guy now, from primer through clearcoat.


I suspect the problem was that of the primer, not of the topcoats.

Ever notice(d) what the 1987 and 88 (and perhaps 89) automobiles with
light blue and gray paint did? Most, if not all had the paint peeling
off in sheets or fading all of the way off, without starting to strip
them. You may have not noticed that, but I did. I had one of the
automobiles that had said light blue paint. I would stand there
(usually at the gas pump while I was doing nothing else) and peel off
silver dollar sized sheets of topcoat with my fingernail. There was a
recall that I did not take advantage of, (because I was a contractor,
with 7 people depending on my van being there with the tools everyday)
until it was too late, and had expired. Expired? Ridiculous. That
sort of thing should never expire. I still have not forgiven GM for
that one.

I had a Ford Taurus that did the exact
same thing. Along with the garbage auto
transmission, I haven't forgiven Ford
either.

I was told that the problem started while the paint companies were
trying to meet new regulations for the amount of volatiles in the paint,
and the new formulas did not have adequate UV resistance, which would
cause the bond between topcoat and primer to break down. The light gray
and blue topcoats were the worst at letting UV through, I guess. I don't
know for sure if that was the real answer, but there was a real
problem. Perhaps that was a common link with your problem.

I was told that the reason it happened is
that Ford purposely omitted the primer and
put the color coat directly on the sheetmetal.