I thought I'd share my misfortune here in hopes it may save someone else greif. Also to support my feeling on the use of primer before paint.
This is a Tamiya 1/20 Tyrrell 020 I WAS working on. In the process of spraying on a clear coat this happened=
The clear coat, an acrylic lacquer attacked part of the white paint underneath. The white is a Testors enamel. The odd thing is it only attacked the enamel where the primer underneath the white had been sanded down(almost off). The white was then resprayed(w/ an A/B). In my haste I forgot to respray the PRIMER. The white with a good coat of primer was unaffected and came out great?
Long story short, I will always use primer on my paint jobs.
Since the livery on this car was going to be a test car(fantasy-what if) I tested some other things along the primer/ no primer lines. And some clearcoat observations. I also assembled what I had done togeather to see what it might of looked like
In this pic, the red on the rear wing was painted over bare black plastic. The red on the front wing over a good primer coat. The reds look way different. And the white on the bonnet(no clearcoat) vs. the white with clearcoat on the tub are also different shades.
The front wing has a Future clearcoat, the rear wing has a acrylic enamel CC and the tub the acrylic lacquer.
I'm going to test some more clearcoat options on the bonnet to see which one keeps the white from changing the least.
Hope this may of shed some light on the primer thing for some, I know it did for me.
Here are a few more pics of the Tyrrell before it goes to the scrap heap. It coulda' been a contender. I think I may go back to trying to build airplanes.