I'm having some issues with the rear hatch on my car. The whole car was resprayed with chemspec products. Scuffed to 600, primed, wetsanded with 800, sprayed with four coats of base, three medium coats of clear, color sanded, then shot with two WET flow coats. Everything looked perfect. It was essentially a no buff job, but I did some color sanding and buffing to improve the distinctness of image and cut back the urethane wave.

Exactly one week later (still polishing it), the rear hatch has shown some strange issues. There appear to be scratches under the base/clear. I did not have this issue when it was sprayed, it just showed up after buffing.

On top of this, on the same hatch, I'm having some issues with body filler. At the same time the scratches under the paint showed up, the four ~1mm depressions that I filled with evercoat polyester putty appear to have shrunk. Here's the whole process I went through to make sure it was all sealed off properly.

-Sand depressions with 180
-Fill/sand (repeated this process three times)
-Prime
-The spots came back through the primer even though they were properly feathered out. Shrinkage issue.
-Primed the whole hatch with three more coats, focusing on the 1mm depressions.
- block Sand with 800
-4 coats of base/three coats of clear
-Got a burn through during color sanding so I just sanded the whole thing with 800 and resprayed base and clear
-Color sand with 1000/two wet coats of clear.

How is it physically possible that sanding scratches showed up through all of this and the spots that were filled with body filler shrunk back as well? There are no other issues on the car.

not allowing the filler being used enough time to cure will cause problems. yup, theres fillers that say can be sanded in,like, 45 minutes, but I personally give fillers 24 hours before sanding.
primer is the same way. I let it sit 24 hours before sanding.


could be the rear hatch being the only area where there was filler work that heat from sunlight is hitting it directly helping the curing/shrinking process.

^The filler was sanded within a few hours, but when I put the final coat on, I let it go overnight. It says to sand in like 20 minutes, but I never trust that.

There are sanding scratches on the whole car now. They look somewhat like swirl marks, but can't be seen in direct sunlight, only from strange angles.

It honestly makes absolutely no sense. I went with 800 grit to make sure that I didn't have this problem. Basecoat was a top of the line product at roughly $300 a gallon with the reducer. The only thing I can think of which would go back to the shrunken body filler as well, is that the primer made a horrible sealer. Perhaps it soaked up some of the solvents from the base coat and is slowly letting them out, which is why I didn't see the scratches/shrinks in the beginning, but do now?

That sounds like an awful lot of paint/clear. If I got it right there are 9 coats of paint and clear.

I would park it in the sun and let it sit for a week. Let everything settle before you do anything else.

As for the filler, I had a batch that did not completely cure as I did not use enough catalyst, I had to scrap it all off and start over, any chance the filler did not cure all the way?