In 1942 the Navy prescribed the use of zinc chromate on operational to inhibit corrosion on the interior surfaces, such as wheel wells and the inside of landing gear doors, of operational aircraft. Was zinc chromate applied to these surfaces on prototypes like the XF6F-1, -2,
-3 and -4. I have seen B&W photos and appears that the surfaces in question may have been left in natural metal, when these aircraft were built in 1942. I have seen B&W photos of other aircraft in which zinc chromate surfaces do not look any different than natural metal.
In msny cases the metals were primed with zinc chromate but then painted over, to provide even better protection. What got confusing was when that paint was aluminum paint. The use of aluminum paint was popular with the Navy in the thirties, but I think had disappeared by the time of the Hellcat. I have seen landing gears painted aluminum color. Don't remember what aircraft they were from. Starting about the WW2 era white paint became popular for landing gear parts and this continued into present day.
According to Navy Air Colors 1911-1945, the Bureau of Aeronautics issued a directive on 22 December 1942 prescribing Interior Green (zinc chromate?) for all interior surfaces. From photographs, I get the impression that some manufacturers, notably Douglas and Consolidated were applying it to their aircraft earlier. It is not clear whether Grumman was using it. Also the First three Hellcat prototypes--the XF6F-1, -2 and -3 were originally finished in either bare metal or aluminum. The -4 was converted from the -1 while in this finish.
If you walked around the Grumman shop areas in the late 60s everything in assembly was one of two shades of chromate green primer. The assembly stands had small hand paint pots to manually touch up where the paint was scratched during assembly. The initial coat was usually sprayed. Initial flight test of aircraft usually started before the final paint job was applied - so you had aircraft flying in the primer or partial primer/final paint scheme. We referred to them as greenies. Make an interesting model -something like an E-2A in partial chromate, some bare metal on the nacelles, some Grey and Stars and Bars on the fuselage sides. Conclusion is in general at least at Grumman still green primer.
No the Aluminum came in bare. The machining, forming, heat treating etc would have destroyed the zinc chromate coating during manufacturing. Small parts were hung on hangers, others singly were spray painted before being sent to the subassembly shops. The spray booths had water walls that collected the overspray and essentially dumped in into a sump near the plant. Periodicly they would let a sump drain - then scrap off the chromate coating for disposal. Led to some major cleanups when environmental concerns surfaced. Long island usues ground water for drinking supply.
Actually a more complicateed operation - at one time Grumman has an automated paint line. The parts got attached to racks there were coded for routes through stripping and cleaning operations to remove manufacturing oils etc, then applied the correct paint coat.
Sometimes the Greenies actually had bare metal that segments that weren't coated yet.
Somewhat OT - but during thte Berlin Airlift the Air Force refused to carry one cargo as being too dangerous --Salt - the dust would corrode their aircraft. The British flew it in on flying boats that had been properly undercoated against sea salt.
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