Wet Blending of 3 Colors on Fokker Dr.1's

[Taz]

Dave- I just noticed you were writing your response (much more detailed than mine) at the same time I wrote my first one and I just read yours right now. I agree with everything you wrote.

It is a crying shame the samples are being mismanaged. Why would anyone want to put a transparency on a box containing fabric or photographs? Even amateurs like me know better than that.

The report on F.I 103/17 states plainly that the upper side was camouflaged in green and the undersides in blue.

The part of your story that interests me is the light blue tinted dope. None of the Triplanes had a topside coat of light blue paint, in my opinion, but that does not preclude some blue tinted dope. Is there any evidence of this light blue tinted dope on the sample of the top side of 144/17, or does it look like it was reserved for the bottom? Rereading your post, it would seem the upper side color was applied over clear dope and not light blue. Maybe we will puzzle this all out eventually.

Taz
Terry Phillips

[Romani]

Originally Posted by RAGIII

Try this thread for fun: There are plenty more where this one came from,

Fokker olive brown streaky and aniline: A new hypothesis

In this thread RAG wrote:

Originally Posted by RAGIII

2.There is also that Nagging report that 588/17 [Gefreiter Preiss] was overall blue with with Olive Green Streaks. It has been suggested that this was merely sloppy report writing. That being said, the report writer was there, we were not!
There appears to be no return of the underside blue on pictures of this aircraft. Again it matters not if I agree or disagree, just that there is a first hand report that can not be totally dismissed out of hand.

Here's the text of said report

British report into Dr.I (583)588/17 (RAF No G/2Bde/15 held by the PRO) under “General” “It appears similar in construction to previous machines of this type brought down. It is camouflaged in a green and blue mixture on the upper surfaces, the lower surfaces of the planes being light blue.”

Taz just posted

Originally Posted by Taz

I have photographic proof that 588/17 had a normal Dr.I finish with returned light blue paint, so one more nail in the light blue undercoat theory.

I recalled only vaguely what the "returned paint" is but I found the description by TAZ

Originally Posted by Taz

.. blue returns over the streaks. The streaking was done first to the fuselage and tailplane (and wings), then light blue paint was applied, including a light blue border of returned paint which covered (cleaned up) the ends of the streaks on the fuselage and tailplane, but not the wings, where demarcation was fairly clean with a seam on the front and a thin wire trailing edge on the rear.Dark paint slopped over either the front or rear edge would be covered with later blue paint application...

Originally Posted by RAGIII

I personally see tonal variations that CAN be explained by thinned dope applied over a greyish CDL as being feasable for explaining most pictures.
...
My other thoughts are that a more Grey Linen "Could" be part of the reason for the Bluish uppersurface scheme on the F1s and some of the others?( This is merely theory/conjecture) based on Nowarras comment about the Grey Courtrai Linen used by Fokker.

After reading about linen, I do agree (I have to write a post about it soon). It seems to me from the photographic evidence that the streaky finish might have been applied in a thinned form in the early Fokker triplanes (the F series) and more cammo was applied in production DrIs.

Other reports

Since images from fabric samples of Fokker Dr.1 144/17 have been posted, the information here is for those who don't have access to the report. The written description on the above mentioned triplane comes from PRO file AIR1/1061/204/5/1578 :

" It is camouflaged light and dark green on the upper surfaces and light blue on the lower."

And here's the infamous fake report

From PRO FILE AIR 1 BOX 1061 This,in part is from the report on FI 103/17

" The entire upper and side surfaces are doped in various shades of green, blue and grey "

" Lower surfaces are greyish blue"

Originally Posted by RAGIII

4.Chromium Yellow and carbon Black would make OLIVE GREEN! I don't know how you could mix these colors and come up with BROWN?

It seems the consensus is moving towards accepting the Fokker triplanes were more green than brown, in viewing the latest posts about fabric samples.

And we had a statement of a mechanic that the triplanes coloration went from green to brown

Huntley wrote that the dark olive "was then coated with a dark linseed oil varnish wich had the effect of transforming the dark olive to a brownish shade of green"


Dan San pointed out that varnish was copal based and not linseed oil.



At this time, I will repost Dan San about method of application and pigments

1. The linen covered surface is given : Fuselage one coat of clear dope. Wings and tails, two coats of clear dope. (Why one coat on the fuselage? Aircraft dope is on the critical shortage list.)

2. One coat of olive-brown ( I know this gives you "green guys fits.) lacquer streaking on the upper surfaces of the wings, tailplane and top of the fuselage turtle-deck and sides.

3. One coat of sky blue on the under-side of the wings, tailplane and fuselage. The sky blue is wrapped around the lower longeron 20mm up the sides of the fuselage and around the upper surface of the tailplane 20 mm.

4. All the fabric surfaces are given one coat of clear varnish to waterpoof the fabric surfaces.

...

The three wing drawings Bill of Materials only call out one Anilinfarbepulver, not two, not three, or four, only one colored powder. For the upper wing; 40 grams of this colored powder. Forty grams when mixed with the vehicle and spirits is the streaking lacquer.


Blue skies,
Dan-San

Now shamelessly quoting myself

(regarding the Fokker olive-green-brown)

Now, the colors used and the method are strikingly similar to the making of the british Khaki PC10 (with the exception of aniline). I think Fokker paint team was imitating the British, but their product was somewhat greener than Khaki and improved on it by applying it as a disruptive camo scheme, v.g, streaks.

Regarding the different applications of streaky camo, sometimes airplanes look very "light" like the olive was applied very sparingly, and sometimes they look darker,
Taz wrote

Romani- Remember one thing. This streaked finish was not new on the Fokker Dr.I. Fokker used it on the license built AEG C.IV and also on the Fokker D.III, D.IV and D.V (and possibly late D.IIs) probably as early as the fall of 1916. he streaking on these aircraft varies from very light like the F.Is to fairly dark like on most Dr.Is. I agree with your conclusions on no blue overpaint on the F.Is and just lighter streaking like contemporary AEGs and some M series biplanes. Fokker D.IVs delivered as late as March 1918 had darker streaking like the Dr.I.

Well, we are getting to the end of the story. From various sources we have concluded the color is olive green wich turned to brown.

Yellow Cr is some kind of metallic oxide and the darkening of it might be caused by a similar oxidation process as in British PC10 khaki,
...
Your description of Yellow Cr and its uses might explain why some metallic parts of some German fighters were painted in what has been called a "dark green" , things like struts or the tachometer bar in the Fokker DVII wich are the only examples I can recall right now.

Air-hed countered that

as an oxide, the lead chromate is not going to oxidize further!

The thread came at an abrupt end and I couldn't answer and eventually the thread got locked. Now is my chance

Really? Riddle me this. We have the following facts:

1) British khaki, aka PC10 wich under exposure to the sun grew darker and browner

2) Fokker olive green wich under exposure to the sun became brown

What's happening here? We have ruled out linseed oil darknening, because it takes too long, and DSA said the varnish was copal (actually amber resin)

We have a process of oxidation going on, wich turns the yellow ochre (a ferric oxide) in the british paint more orange wich in turn makes it browner. In a nutshell is that. The oxidation is due to exposure to sunlight, and this has to do something with photoelectric effect. I am out of my depth here, but that's the basic physics behind the effect.


Now we experience similar results with the Fokker olive paint, but we don't know its composition. Could analysis of the Fokker fabric samples of the IWM yield the chemical composition of the paint, or such a test would be destructive? I don't know.

So we have found a suspect.

We have fabric samples colored in olive brown, and none of the pigments mentioned in the component list are capable of producing such color, the only suspect is the unknown "Anilinfarbepulver"

We now something similar to yellow chrome + black (you are referred to Air-hed post) was used as anti corrosion primer to paint green metal fixtures inside German airplanes or the inner side of the cowling.

So either the Anilinfarbepulver is a pigment made of yellow chrome and black, and was presented in the factory in ready to use cans,, or is something different that behaves in a similar way.

So end of the line here. I don't know enough about paints to continue. What's the difference between a dye and a pigment?

Huntley says something that intrigues me:
(regarding streaky planes, not limited to the DrI)

These aircraft came at a time when Germany was making every effort to use only cellulose for shrink-dope purposes and was evolving schemes to use dyes and other paint forms for its camouflage and markings


I only have a basic understanding of how a dye works, but I am beginning to think that Fokker achieved the same result as the British with their PC10 by using a dye that would recquire less pigment.

I mean, from experience, if I want to paint a wall
blue, I can use straight blue paint from the can (many cans), or I can dissolve a little bit of blue dye into a big can of solvent/white paint, and I can stretch it, making it more cost efficient. I think that's how it works. Please enlighten me!

Why "anilin" on the tag? Just want to figure out if it means anything.


EDIT: Ok, there are some things that I will have to change after reading more carefully Dave Welsh posts, *groan* please take this summary as the state of the discussion before this thread.

[sobrien]

So Mr. Schultz's coloring of his Dr. 1 models was artistic license or colorful interpretation? Or highly improbable? Or based on unfounded theory?

Sobrien

[jumpinjan]

From my experience & understanding on how light behaves, I just want to point out some clarification on some things. From what I understand, the Fokker list of materials included a yellow pigment (yellow ferric oxide?) and black pigment. If the yellow pigment is close to "Chrome Yellow" (or the yellow hue on color plate #3 of the Methuen book), and if it is mixed with black, the resultant color is olive.....not green. The Methuen coloring scheme dramatically proves this point and actually explains this unique perception, "...The warm colors are profoundly affected by shading. Darkening yellow results in a green shift, as we see in the first three color plates. This shift is primarily psychological." This psychological shift to green maybe from our eye's intense sensitivity & spectral resolution to the green wavelengths?
Another point is this color shift from an original "olive" color to a brown color. My theory is this shift is due to the ferric oxide particles reacting to the UV sunlight, and changing from Chrome yellow (color plate 3) to a yellowish orange hue (like the hues on color plates 5, 6 & 7). Has anyone investigated into this theory, I wonder?
Jan

[RAGIII]

Originally Posted by sobrien

So Mr. Schultz's coloring of his Dr. 1 models was artistic license or colorful interpretation? Or highly improbable? Or based on unfounded theory?

Sobrien

I am deleting my original answer as I have just read Taz and Daves posts. I think you missed one comment that is relevant, Don't be too Dogmatic :-)
RAGIII

[Taz]

RAGIII- I was about to answer your query, but glad to see you found what you wanted. Dave Roberts, Dan-San Abbott, and Manfred Thiemeyer have the most experience with actual samples of Dr.I fabric and their knowledge eventually adds up to a very close appriximation of how a Dr.I was finished. Alan Toelle offers the most scientific analysis of the samples he has examined. As Dave says, the green streaking turned brown over 90 years or so and this explains Dan-San's Methuen references, which are, I believe, too brown. Dave's theory that a dark gray was the dark streaks is plausible. Manfred has the whole picture if he decides to enlighten us. He has had more access to WW-I pilots, fabric samples, etc than anyone because he has been interviewing WW-I participants for over four decades. Any information we get from him is invaluable.

Here is a small carrot. This is an image of Dr.I 588/17 from Peter Grosz' collection. It clearly shows 588/17 with returned blue paint. Therefore no blue overpaint on the upper surfaces.

Taz
Terry Phillips

Dr.I 588 17 WN 2258 Jasta 14 Phalempin Detail.jpg

[Dan_San_Abbott]

Gentlemen:

I Wish to clear a few things up.
1.When a bill of materials is prepared by the draftsman, he must list each and everything that is used to make that part or component. The wing spar and the drawing/part number. Each brad or nail by composition and size. They are not all thrown in a pot called nails, each specific color of paint/dope.
2.There is only one aniline powder listed, so the finish color is one color. It is my opinion that the variations in value are achieved by the viscosity of the lacquer. It is extremely difficult to brush lacquer/dope that thin.
3. The assumptions that the aniline powder is chrome yellow and carbon black it just that an assumption not supported by fact.
4. I have defined the color as "olive brown", that is based on the Methuen Handbook of Colour technical definition of the color. From what I observed in September 1972, the colour of the fabric sample was a dark olive green/brown.
Brown is the color definition of two opposite color mixed together. It can vary all over the board. But when it is codified it become specific as to hue, value, intensity and tone.
5. If the observer is not color trained you will get observations like "green and blue" with light green on the undersides. The undersides were turquoise, that is not light blue, unless you lack color skills.
Blue skies,
Dan-San
P.S. P.C. 10 was first made with chrome yellow and carbon black. Production dope was iron oxide and carbon black= BROWN! First production S.E.5 were brown. Read Sagitarrious Rising by Cecil Lewis.

[Sreiko]

Two members here stated, if I have understand correctly, that in the top side color was used two color, yellow and black and mixed they are resulted in green. This is clearly why is this color on the images very dark. Watch the soviet airplanes who have similar mixed topside green and result is the same- mid green is very dark on images.

Some time before I have read discussion's about the color of the engine cowling of the Japanese warplanes in WW2. there is researchers who said that this is black and many who said that the color is blue black. And one gentlemen is take part here and start talking about the quality of the color. He said that his father was soon after the WW2 painted his car black nut after few years they are get bluish shade.

Not expert at all but two thing have to be considered:

- what material was in stock at the Fokker at that time for painting
- for sure quality of that time is not the same as today

[Welsh Dave]

Dyes and pigments tend to be lumped together as both are colouring materials, but the actual difference is this:

A dye is a strong colouring material that dissolves in a fluid such as water or oil and imparts its colour to that fluid.

A pigment is a powder that mixes with a fluid but does not dissolve in it.

Fokker's camouflage paint uses both. On the uppersurfaces clear linseed oil varnish is mixed with zinc oxide powder (a white pigment) and olive-coloured aniline dye powder. The dye dissolves in the varnish, albeit not completely in some parts, and coats the particles of zinc oxide, turning them olive.

In this case, the paint that appears lightest when applied contains the least zinc oxide and dye, and is the most translucent. Darker streaks are done with a stronger mix of the same colour, i.e. slightly more zinc oxide and a lot more dye, in the same medium. It is a matter of strengthening pigmentation, not of diluting one paint to get a lighter shade. The resulting surface is smooth and slightly glossy, more so than that of the eggshell-finish paint supplied for national markings.

When the paint deteriorates, as it has in the IWM, dye comes off the larger zinc oxide particles to reveal them as white spots.

Also, mentioned by a famous WW1 mechanic, there was a translucent dark grey paint, responsible for the darkest streaks. A sample of this has now turned up in the IWM, and is exactly as described - dirty-looking deep grey, almost black, which brushes out to near-transparency. Any zinc oxide content was impossible to determine on site. It has been called "Erdgrau", i.e. earth grey, so there may be some colour in it, although I was unable to discern any under the available lighting.

The underside paint is a mixture of a proprietory blue varnish, presumably transparent, dye based and quite dark, and zinc oxide pigment in sufficient quantity to make it lighter and almost opaque. There may be extra varnish added to the mixture to keep it workable. The finish is almost matt.

If you go to a paint store to get a colour mixed, you'll see exactly the same process. A can of white-pigmented paint, of whatever composition, is put under the mixing machine and intense dye-based colours are dribbled into it into the right proportions to obtain the shade you need. The can is then capped and vigorously shaken to mix the components.

Artists' paints are similar. Some contain pigments alone, while others have a combination of pigment and dye.

Aniline is a toxic distillate of benzine which reacts with other chemicals to produce a wide range of very strong coloured dyes, many of which are still in use today. Aniline dyes are complex compounds, not toxic in their final state, and most are very stable. The Fokker olive may be one that changes hue over time.

Germany was among the pioneers of aniline dye development and manufacture; the world-famous BASF company is the Badische Anilin- und Soda-Fabrik.

[Sreiko]

Dave- thank you for the details and info. One question- following of the some logic Fokker Dr.I and Fokker D.VII of first series could have the same paint on topside?