Powder Coating Thickness

[kaleem546]

We are doing Powder Coating on large steel parts of various geometries. We are applying manually hybrid epoxy in RAL 7035 shade after doing Iron phosphating.
The coating thickness specified by the customer ranges between 60-80 microns, but in actual it ranges between 45-110 micron at different points throughout the surface because of the nature of the parts.

How would I best justify the customer of this deviation.

 

[TVP]

What are the requirements for the parts? Why are they being coated-- aesthetics? corrosion resistance? Why did the customer specify a range, instead of a minimum or maximum? Tolerancing and fit? Minimum corrosion resistance? Perhaps with some additional detail this can be further addressed.