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Light Earth / Light Green versus DE /DG


occa

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That is very interesting indeed.

Nick anyways I would not mind at all if this thread gets a turn so feel free to post whatever you have ...

Btw I cannot access your blogs anymore, it says I am not invited for both.

The one for the Japanese colors was free for all before and I had an invitation for the other one.

What changed?

Drop me a pm with your email and I'll re-send an invitation for amair4raf. Aviation of Japan is currently down but will be public access when and if it is up again.

Re the "puzzle" LG and LE were supposed to be "shadow shades" for DG and DE but the reflectivity is odd:-

DG = 7-8%

DE = 13%

LG = 11%

LE = 30%

When I measured these I thought I had made an error but re-calculating together with checking RAE and other records confirms the values. Why was LE so bright? More than twice the reflectivity of Dark Earth and not to the same ratio of contrast as DG and DE. That was 6-7% but the lighter colours are 19%.

Nick

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Light Earth and Light Green were shadow shades for biplanes. However by 1943 I suspect most would have been out of service, but not in India for second line duties?

How many aircraft can be covered with 150 gallons anyway?

Tiger Moths would have still remained in use, and, as well, as "how many," you should ask "how often."

During a 1943 visit to SEAC, an I.C.I. executive found that, where a doped fabric finish was expected to last about 5 years, in the U.K., deterioration/cracking of the finish, leading to damage to the fabric and grounding of the aircraft, could take as little as 3 months in the heat of India. He found that Warwicks were unserviceable in 100-120 days.

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It was brought up that the camoflage regulations had to be followed strictly

Obviously it wasn't always like that like this Hudson proves:

Pic is from IWM

What are you suggesting that this proves?

Following the logic does it prove that fuselage roundels were sometimes painted red/yellow/blue/yellow?

Thought not.

Peter

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Tiger Moths would have still remained in use, and, as well, as "how many," you should ask "how often."

During a 1943 visit to SEAC, an I.C.I. executive found that, where a doped fabric finish was expected to last about 5 years, in the U.K., deterioration/cracking of the finish, leading to damage to the fabric and grounding of the aircraft, could take as little as 3 months in the heat of India. He found that Warwicks were unserviceable in 100-120 days.

Point taken. Indian Tiger Moths and other fabric covered machines must have been weighed down with all the repaints!

Seriously and provoking more thread drift, constant repaints would presumably require recovering as a matter of recourse after a while to prevent weight gain. That being so, has anyone come across requisitions for large quantities of Irish linen and dope to match the requests for paint?

Trevor

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Probably not, since light aircraft used a lighter cloth, usually Egyptian cotton, not Irish linen. Madapolam, as used on the Mosquito, was a superior quality cotton fabric.

Edgar

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It was brought up that the camoflage regulations had to be followed strictly

Obviously it wasn't always like that like this Hudson proves:

Pic is from IWM

That just looks like a very heavily weathered TSS aircraft. Airframes did not weather in the neat, equal symmetrical fashion that many like to finish their models. I'd suggest the dark green patch on top of the fuselage might be the original factory green showing through, or it might be some re-painting of the most weathered area

Edited by Greg B
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Something I haven't seen mentioned in any of these threads is just how dirty the air was before the original 1956 Clean Air Act

Now while airfields were out in the county and usually well removed from close proximity to the worst by-products of dark satanic mills, coal was the normal fuel for everyday use; railways, domestic and office heating, industrial plants all depended on coal. Coal produces soot and soot settles on everything; coal smoke also tends to contain sulphur and sulphur reacts with white lead turning it black over time. I doubt that white lead was ever widely used in aircraft finishes, but lead compounds from engine exhausts would have been exposed to the same environment

70 years after the fact it is probably very hard to comprehend how quickly any freshly painted surface change colour after a even short exposure to the sooty and corrosive atmosphere of the coal age

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And groundcrews took an immense pride in keeping their charges clean (pilots only borrowed them, remember.) Also, from 1942, there was a new trade of Aircraft Finisher, one of whose regular tasks was to retouch any paint damage, sand it down with fine wet-and-dry paper, then wash down the whole airframe with clean water.

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I doubt that white lead was ever widely used in aircraft finishes, but lead compounds from engine exhausts would have been exposed to the same environment

Actually it was. At the beginning of the war white lead still provided the bulk of white pigment for oil based paints. It was restricted to conserve it with an intention that there should be a minimum use in camouflage paints but it was used in aircraft cellulose lacquers. The darkening of paints with exposure is probably counter-intuitive to most modellers who focus more on a presumption of 'fading' when weathering.

Nick

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Actually it was. At the beginning of the war white lead still provided the bulk of white pigment for oil based paints. It was restricted to conserve it with an intention that there should be a minimum use in camouflage paints but it was used in aircraft cellulose lacquers. The darkening of paints with exposure is probably counter-intuitive to most modellers who focus more on a presumption of 'fading' when weathering.

Nick

Seen not infrequently in "Old Masters" where the Flake White has markedly changed colour, for very similar reasons. I remember my art teacher loudly bemoaning having to change to zinc or titanium white.

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Well that's interesting. You learn something very day - though I should never have assumed such a thing in the first place.

If white lead was in use even in limited amounts, then the differences in tones could well be explained by nothing more than differences in the age of the paint, without the need to engage with theories regarding the use of non official colours. If one of the ingredients of your carefully prepared mix decides to stop being white and turns black instead It makes colour matching out of the tin a very difficult business indeed

Aidrian

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Well that's interesting. You learn something very day - though I should never have assumed such a thing in the first place.

If white lead was in use even in limited amounts, then the differences in tones could well be explained by nothing more than differences in the age of the paint, without the need to engage with theories regarding the use of non official colours. If one of the ingredients of your carefully prepared mix decides to stop being white and turns black instead It makes colour matching out of the tin a very difficult business indeed

Aidrian

Absolutely. I think there was a comment a week or two back (I can't remember where - perhaps in a discussion around Olive Drab?) from Nick (again IIRC) about the effect of atmospheric chemistry on "chrome yellow" which could give further colour shifts.

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Looking again at the picture of the Wellington, I wonder if a colour may look darker and lighter at the same moment (the DG), due perhaps to different parts of the brain being triggered by the different effects of ageing.

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I'm sure there's as often much psychology as there is physics at work in looking at pictures of old aeroplanes

Now I am not suggesting this as a serious research tool for finishing the perfect scale model but there are a number of shareware/free utilities that will let you click on a pixel and will give you the RGB value. If the values are different then it's on the image file - if the same on two areas that appear different your mind is creating the difference.

Do be careful to sample multiple pixels across an area rather than a single pixel as a noisy image is likely to include a lot of pixels of quite different colours in close proximity

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Having followed both threads with interest I wonder that Dark Earth may have suffered the same problems in batch control as did Olive Drab in the US. Could there have been some underlying issues with the pigments and the mix. Certainly both the Hurricane and Wellington pics show a very light shade in comparison with what we are led to expect that the ideal DE should be.

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Drop me a pm with your email and I'll re-send an invitation for amair4raf. Aviation of Japan is currently down but will be public access when and if it is up again.

Re the "puzzle" LG and LE were supposed to be "shadow shades" for DG and DE but the reflectivity is odd:-

DG = 7-8%

DE = 13%

LG = 11%

LE = 30%

When I measured these I thought I had made an error but re-calculating together with checking RAE and other records confirms the values. Why was LE so bright? More than twice the reflectivity of Dark Earth and not to the same ratio of contrast as DG and DE. That was 6-7% but the lighter colours are 19%.

Nick

Am I right to assume that in B/W photos this results in a much bigger contrast for LE / LG than for DG / DE ?

Very interesting find anyways.

Thank you for the offer Nick, will send a PM later.

Martin

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Am I right to assume that in B/W photos this results in a much bigger contrast for LE / LG than for DG / DE ?

Very interesting find anyways.

Thank you for the offer Nick, will send a PM later.

Martin

All things being equal it should but it doesn't always present that way and there is inconsistency even in different images of the same aircraft.

Nick

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  • 9 months later...
  • 2 months later...

Another photo with extraordinary light looking top colours:

55c67a132fa94.jpg

Notice how the trees on the ground have a darker natural green, and the colours on the AC look halfway fresh and NOT much faded

I took the photo from Etienne's Photo Stream:

https://www.flickr.com/photos/8270787@N07/sets/72157605269786717

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Is it just because it's bright sunlight? I say that because the roundel looks bright too.

Partially maybe, but IMO it doesn't fully explain the light tones.

Can anyone please lead me to online chips of DG/DE and LG/LE that are as reliable as possible ?

I would like to to try overlaying these chips to the photo for comparison.

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this will probably mark me as an idiot, but im having a foray int0 WW2 with a mosquito im building. What is this 'chalking' you speak of?..is it fading of the paint or a finish applied to dull down the paint?

cheers

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Chalking basically is where the surface pigment of a colour begins to break down and bleach out.

Not quite. The paint binder in the exposed top layer is oxidised by photocatalytic degradation. This reduces any gloss and results in a friable powdery layer of greyish white on the surface of the paint, like a patina. It can be removed by mild abrasion or 'cutting' to reveal the intact layers of paint beneath. It usually occurs where the paint contains anatase type titanium dioxide (white) or extenders like China clay.

Different coloured paints can chalk at different rates and the surface will not show a consistent appearance.

Not the same as actual colour loss although the effect is similar.

Nick

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