Beautiful day for a ride. One of the favorite stopping points to take a break and enjoy the scenery. They have been repairing this dam for quite some time. It had lots of leaks and they were forced to drop the water level of the lake even below the large spill way gates. You can hear the water at the outlet below.
•The white staining with my experience is caused by moisture absorption during wave solder/cleaning. You are probably using a "matte" finish LPI which is much more likely to occur than using a semi-gloss or glossy finish. During solder mask processing the main steps that can affect white staining would be tack dry, exposure level and cure (post bake). As you only see white staining on one side of the panels (side specific) you could ask your board supplier how the panels are processed and ...
