chromate green vs interior green

I believe chromate green (or zinc chromate) has a yellower tint. They also have a "chomate yellow" that was also used on aircraft interiors. They somehow protect the metal from corrosion and those kind of stuff (oxidation, some wear, etc). I hope this helps.
~~~MarkY

You are correct, Mark.

We used to use alot of the "Rust-Stop" on my ship, and when painted and dried, it turned a lovely green hue. Had something to do with the interaction of the rust and the protectant, I guess. Anyway, the green tint is actually the protective coating against rust and corrosion.

demono69

you see, how would we amateurs know that? What is the difference between chromate and interior green though? Are they the same?

Zinc Chromate and Interior green are two different colors. Interior Green is essentially your standard Zinc Chromate tinted with black, giving it a noticably darker hue. It was used a lot mainly because of its great anti-glare properties. Zinc Chromate can vary in color from a kind of mustard yellow to a sour apple green. Zinc Chromate was proven early on to be an excellent corrosion inhibitor as apposed to silver or just leaving the surfaces natural metal. Nowadays, like here at school we can no longer use Zinc Chromate to prime any parts or repairs we make besause it's extremely toxic and the EPA doesn't like that much...

Zinc hydrochromate (Empirical formula ZnCrO4*4Zn(OH)2) aka Chromium zinc oxide / Zinc tetraoxychromate / Chromic acid / zinc salt

The EPA thinks highly of it, as in "WARNING: CARCINOGENIC! PREVENT DISPERSION OF DUST! AVOID ALL CONTACT! Sweep spilled substance into containers; if appropriate, moisten first to prevent dusting. Do NOT let this chemical enter the environment. (Extra personal protection: P3 filter respirator for toxic particles). Lowest published lethal dose: 30 mg/kg. Zinc chromate is the most potent carcinogen among chromates commonly found in industrial settings."

Another zinc chromate is dark green to black and has a different composition: ZnCr2O4*4Zn(OH)2

Nice disclaimer Tom.

Chromate Green when applied to aircraft outer sides has a yellow-green tint and when they have dried and been exposed to light will actually look yellow. Chromate Green is one of the primary bases used on military aircraft for corrosion control because it is easy to apply and it is light enough that other colors such as yellow, red, orange, and the tint white are able to be applied over the top of them and not show through. On top of that Green Chromate is used in areas where essisantl fluids are expected to drip or leak from. They will be stand out better against it and wont be corrodied away due to these fluids leaking over it.

Interior green is used to simulate the OD green color that is used as fabric for things such as cargo netting, seats,straps, and similar items found in the cockpit of a modern day aircraft.

"Boeing Green" has got to be one of the toughest primers going. After alodining parts (aluminum), then priming with "Boeing" primer, it takes a lot to remove that stuff. It isn't the smoothest primer in the world but it seems to be the toughest. We use that at my shop. We still use the "yellow" zinc- chromate on dis-similer metal applications but give me "Boeing" green every time!

I won't mention the company I worked for, but all I recall is that their earlier aircraft where nearly olive drab in color. Suddenly, the EPA had a coniption about the composition of the stuff and they swtiched to another that was more limey in color and looked more like the Zinc Chromate. It isn't Zinc Chromate but it's damned close in color.
Dana

Probably calcium chrome phosphate. When I was researching 4BO (a deep topic in itself) aka "Russian Olive" or "Russian Armor Green", I found that the folks that made "Zinc Kron" (a yellow paint based on zinc hydrochromate that was 15-20% of 4БО) had switched to the much less toxic calcium chrome phosphate instead.

Zinc chromate was first used in the early thirties I believe. I have heard an interesting story concerning the yellow zinc chromate, seems that when they used it in the cockpits and fuselages, it tended to make people airsick so it was relegated to those areas of the aircraft which were not visible in flight. It was later found that while chromate retards corrosion it does not do as good a job as and epoxy enamel primer. That's why most military aircraft have a gloss white appearance in the wheel wells. Most civilian aircraft just do away with primer completly, prefering the loss of weight over percieved benifits of chromate. (probably right, you put two 200 lb people and 26 gallons of gas in a Cessna 150, and you are over max gross weight before you hit the starter).

13b20, this is Qmiester, you forgot - "target destroyed - end of mission, over"

it does not matter what color you put in there. its all about having fun and enjoying yourself. when i read some of these things i just shake my head cause to much of a big deal .

Hey, qmiester! Thanks, it's been <mumble> years since I was in. Can't remember everything, can I! :)

Unless there is undisputable proof that a specific AC used a specific color use whatever you want.

I found that regular zinc chromate model paint is too bright to "scale paint".....so I use interior green.If you are unfamiliar with scale painting check out the painting forum.

imagine your sitting in a b-17 cockpit in real life....then the regular zinc chromate looks correct shade,

now hover over the b-17 in a helicopter so it looks 1/48th scale then look into window....interior green shade looks correct......

get it? same with camouflage

I, personally, don't "scale" paint and if I did I would never try with zinc chromate as it varied in shade from bright yellow to a medium green. I use interior green for cockpits and I think, though I haven't tried it (yet), a wash of zinc chromte would look fantastic. It WILL be tried on my next American AC.

Not sure why you responded this way. The original poster was asking why these colors were chosen, not knowing the chemistry of it all. He didn't ask what colors to use. 

regardless, some people perefer historical accuracy, where others don't. I don't see why you would judge someone in their choices, especially in a hobby where they can do whatever they like, whether or not you like it. 

19 year old thread.  

LOL..I hear ya. Boeing BMS10-11 is that green primer. Used all over the place inside all sorts of sections of the plane, wings, assemblies and fuel tanks.

Eaglecash867

19 year old thread.