Originally Posted by gearheadslife
from what I can tell.. the new(er) paint/primer and original color coat lifted and peels like mid 80's fords, take a razor to it, and it comes off like it's wallpaper..lol but the original primer is not..
it's odd, to say the least.. the feathering shows one repaint.
That is the problem that the OEM has had for decades. The cars where originally painted wet on wet,the original primer applied to the metal rarely failed, it was the color coat on top of the primer that had issues and it is the belief of some people in the industry that the original "primer coat" was left to flash to long before the color coat was applied. Now is this what happened, I'm not sure, I wasn't there but, the explanation does sound reasonable. The early wet on wet primers had a much tighter window than the primers (Epoxy) that we have in the aftermarket today. From the OEM standpoint, they didn't have the time (to labor intensive) to ensure for mechanical adhesion between primer and color, that's why they used the wet on wet system.
This isn't all bad though, because of the adhesion problem seen from OEM paint work, we have evolved to Epoxy primers today giving us extended windows for top coating before the need for sanding, some up to 7 days, this time frame would have been unheard of 20 to 30 years ago. By the way, maybe I'm old school, but, I still prefer to give primers the benefit of sanding, just to give it both the chemical and mechanical adhesion characteristics that allows paint to stick.