Mil-Dtl-64159 CARC (WD CARC water dispersible) does not have the corrosion resistance as a system as does the solvent based systems of Mil-C-46168 or the Mil-Dtl-53039.
The main problem lies in the primer used, either Mil-P-53022 or Mil-P-53030.
Mil-P-53022 is both lead and chromate free but contains corrosion inhibitors. Mil-P-53030 is also lead and chromate free but contains no corrosion inhibitors. While both primers are epoxy based, but corrosion inhabitation systems require a sacrificial anode to inhibit corrosion which these primers contain very little.
Mil-Dtl-64159 CARC type 2 polymeric flattening agents are coarser than the silica based pigments used in the type 1 coating. Combine the coarser topcoat pigment with a primer that contains no corrosion inhibitors and you have a recipe for premature paint system failure.
The only reason that I can see for using real CARC on one of our MV’s is the availability of a flat finish solvent resistant coating. The infrared reflectance means nothing to the hobbyist.
Any marine epoxy that contains chromates will out perform the two mil-spec primers which contain no chromates or lead.