I’m about to start building my Accurate Miniature Avenger and I’m looking that the possibility of having to paint interior green zinc chromate and the yellow one. I just want to know what the difference is between the two aside from its color and where are they usually applied. I have seen some models whose wheel wells are in yellow and the cockpit area in green.
Interior green was pretty standard for interiors. You’ll have to check your refrences on areas like wheel bays, cowling, doors, etc. These areas varied greatly in color, sometimes yellow zinc chromate, green zinc chromate (much brighter than interior green!), even exterior color (landing gear bays sometimes). I guess it all boils down to what the refrences say, and what you like to look at.
Mate,
I really depends on the aircraft, and sometimes, the factory that made the particular airframe…Avengers were made in at least two different plants, and they may have had access to differing availability of paint stocks, being fairly distant from each other…Both Grumman and General Motors made them, but changes on the line often meant that virtually identical planes ended up with different paints.
Zinc chromate was a paint additive, a corrosion inhibitor - it wasn’t really a “paint” as such. It tends to be very yellow with a green tint, and is very sensitive to UV light. Because of this, it was usually used in areas where there was no crew access or in areas that were totally closed over (like inside wings and other structures.
To give it more durability in higher wear areas (cockpits, wheel wells, inside engine bays, etc), lamp black was added, giving the same paint a darker, more greenish tint, similar to the current Boeing BMS 10-11.
Other manufacturers often used darker colors - Bell and Republic used bronze green and cockpit green…but not always! Confusing, and painful.
Really, it just depends on the aircraft…some people prefer to research (in depth) a particular airframe and then model that, trying for total accuracy…others take it all with a grain of salt and do what feels right…at the end of the day, you have to please yourself.
Good luck!
The specification for Yellow-Green, used in aircraft interiors was given as:
Zinc Chromate (Yellow) Primer: 1 Gallon
Toluene Substitute: 1 Gallon.
Black Enamel or Paste 1 Gallon.
Originally 4oz of Aluminium Powder was also included.
! gallon of ‘black’ would appear to be extremely excessive and it is believed to be a typo or mistake for a tenth of a gallon, a more reasonable quantity.
There were two reasons for turning ‘yellow’ chromate ‘green’. One was that zinc chromate is sensitive to UV light and the Carbon Black helped to reduce the photolytic reactions the UV induced. (Perhaps the Aluminium Powder was included for the same reason.) The second was that green was thought to cause less eyestrain than the bright yellow of the raw pigment. In fact the USAAF issued a directive during WW II forbidding the use of Yellow Chromate in crew areas. In September 1943 the yellow/black mix was replaced by ANA611 which designated black tinted Zinc Chromate primer as Interior Green.
For a more detailed explanation of the various interior colours used on US aircraft see
http://www.ipmsstockholm.org/magazine/2004/01/stuff_eng_interior_colours_us.htm
Constructor,
Here is a very good article written awhile back and it has alot of great info that will help you out building US aircraft during WWII. here is the website
http://www.ipmsstockholm.org/magazine/2004/01/stuff_eng_interior_colours_us.htm
Also, check the instructions for the interior…I recall from my bulid that “Bronze Green” was called for in the interior. THis is closer to interior green than to zin chromate green.
Actually Bronze Green is much darker than Interior Green- Humbrol makes a good match shade in their line,or Testors MM has a close shade as Marine Corps Green in their Acryl and MMII line
Generally speaking, early Avengers built by Grumman (TBF), the cockpit interior was a bronze green and the inside of the cowl, light gray. On the Eastern built Avengers (TBM) the interiors were Interior Green. On all, the under carriage bays were the exterior underside color.
HTH,
Gary
Here are a few photos I took of an Avenger just a week and a half ago…enjoy…
Mike
To my eye, if you add a little black to yellow zinc chromate you get green zinc chromate - sort of an apple green. If you add a little black to green zinc chromate you get interior green. More of a bright olive color than the green zinc chromate.
As for the exact shade of green zinc chromate, I don’t sweat it, it varied an awful lot in actual use. I like to paint different structures slightly different shades, a tiny bit more or less black added. That makes the interior more interesting and I think it represents different components that were primered at subcontractors who used different lot/mixes of paint.
Be logical about it, the whole basic structure would be the same shade and then bolted on parts like turrets, radio racks, bomb racks, seats might vary in shade.
Another reason for green zinc chromate was so the contractor doing the painting could ensure a good second coat. The first coat was painted with yellow zinc chromate and the second with black added so the painter could make sure they had complete coverage with the second coat. (and so the inspectors could tell he (or just as probably back then, she) did the job properly)