What temp did they bake it? Usually all I hear on here is non accelerated drying. Wonder if that caused some issue. Let’s let others chime in but if the foundation clear isn’t adhering to the playfield, I’m not sure doing anything above it will help.

The playfield needed to be prepped properly before getting the clear coat. Cleaned thoroughly and scuffed with a red scotch brite. The clear needs something physical to bond to.This might have been done, I can’t tell from the pictures. When you sanded the playfield, you basically opened up the clear to gas out more. This can have a reaction with the glue used for the masking materials. It is better to wait a few days after sanding before applying masking materials. Playfield should be cleaned again before applying masking and the masking materials should be removed as soon as possible. Another thing I would suggest is to get away from using sandpaper that needs to be used wet. There are plenty of sandpaper types used in automotive refinishing that work just as well dry. No need to introduce moister to your wood playfield.

Make sure you spray within the range given by the manufacturer. If you are too far away or don’t lay enough down you may get orange peel.

I use 600 or 800 grit dry to sand between coats.

600 grit dry. I also just noticed, were the wood rails on the sides of the playfield left on when it was clear coated? Those should have been removed. The screws for the pop bumper coil mounting brackets should have been removed also. If stuff like that is left on and just clear coated over or around it will cause problems.

Looking really good. I know how much time and effort this requires.

I would recommend taking off the wood side rails too.

I'm stripping down a playfield that someone cleared 10 years ago, There was a lot of clear that was under those wood side rails and it continued to bleed out after they sprayed it. So it messed up that corner and wasn't a smooth finish.

Very nice work, looks great!