Fokker Streaky Camouflage Fabric - Duration Test

[AchimEngels]

Dan-San,

have you ever doped an aircraft fabric skin? Did you get a useful result with three coats only? If so let me know about your technique. I would very much love to learn what I do wrong. I wounder if you have ever seen what happens to one coat of cellulose acetate once another one is applied on top of it.

By the way. cellulose tells nothing. Did Fokker use cellulose nitrate or did Fokker use cellulose Acetate? What dope was more common at that time? From one piece of definetly Fokker fabric I have, I can see that it appears like he used acetate as a solvent.

I will go and ask Paul directly for copies of the materials you mentioned.

Sometimes I wounder how you come to know what I do and what I did not do. I must admit that I do not know about the documents you mentioned. They would for sure be of interest. But I know about semiliar other contemporary documents.

Please note that these do not have anything to do with the "fabric painting exercise" I be doing right now. No matter what you think, I learned a lot already from these early stages of the experiment. It is all written down and will be compiled to a very interesting report in the end.

I do not want to be an expert. I do not even be interested in judging others me to be one, because I am far from it. I want to see what happens to the materials. As a matter of fact it is very interesting to stand up in the morning going outside to see what happened. And I love to share this with others.

The idea is to see first hand what happens during those first 120 days. Is the way I approach it unprofessional? Maybe, because I am not a scientist. But it is good enough for me to tell me what I want to know.

You still missed to answer my questions, but this time it appears to me that you did provide the sources where to find what you said. I will see what the documents reveal you mentioned that are held by Paul Leamen.

Best
Achim

[wulffo]

food for thought and nothing else....

i know that this is a very bad picture but nevertheless a 1918 light blue turned into a perfect turquoise due to uv light exposure over time. if the books had not been stored offset i would have sworn that the original color has always been turquoise. as soon as i get around to buying a proper digital camera i will post a better image....

[Dan_San_Abbott]

Achim:
* *for your information, during WW2 my Miltary Occupational specialty was Parachute Rigger, Fabric Technician. This required training in all fabric work which included aircraft covering. I was invovled in covering a Waco Utility Cargo aircraft. In the CBI Theatre recovering about 15 C-47 elevators and one left C-47 aileron. *Yes Achim ,I have been around the pole and I know what the score is. *I spent 49 year in the design of, and manufacture of parachutes and in the course, I acquired a fairly large knowledge of fabrics, webbings, tapes and cordage. *So, I do know what I am talking about.
* *In the field of our interest, I have been engaged in the study of WWI aviation, aircraft, people, history of battles, but mostly color and markings since I was 14, that was 65 years ago.
* *I have made an intense study of German colors and markings since 1972, (I believe that was the year you were born!) so if nothing else I have absorbed some information during that time. *
* *Achim, take a deep breath and let go, your ego is getting in your way!
* * * * * * * * * * * * * * *Blue skies,
* * * * * * * * * * * * * * * * Dan-San
P.S. E-mail me your address.

[AchimEngels]

Dan-San,

As usually, you have spoken around the core.

Most you said is not new to me. Apart from how many elevators you covered I know quite well what your profession was and so on....and so on.

Did any of these elevators have been covered with three coats of dope? That was the question, nothing more.

Even the Technische Berichte, which you doubtless have read, speak of a usal practise at that time of five to six coats of dope. There is only one context where they speak about two coats only, but you should properly translate it to understand what they talk about.

And just to play the game by your rules - I was at the age of 17 when I covered my first complete aircraft (and that was - hm let me see - one year before you came to know me!)

Dan-San, I will now take a deep a breath and that was it. I will now do what others suggested to me offline.

Have a nice time...

Blue Skies

Achim

P.S. You have my address...

[AchimEngels]

Dan-San,

Please let us lay down the swords. I might have been taken some things here too personel.

Let me close this with the following formal words:

I apologize in due form and would like to express my esteem for the works done within the last decades to you.

Your´s
Achim

[AchimEngels]

Hello,

The saga now continues.

I will do this in two posts, so that nobody will confuse all the information and mix it up.

Subject of this post is the pieces of fabric held at the IWM which are said to have come from Stapenhorst`s 144/17.

At first here are images of the pieces concerned:


Taken directly from above.


Taken at an angle of about 45°.


Taken from above.

As you can see those images have kindly been provided by Dave Watts who was there a few weeks ago.

These images clearly show that Dan-San Abbot is quite right in the describtion of how the pieces do look today. They obviously have not changed a lot since Paul Leaman did examine these in the late 60ies.

However it should be noted that these pieces are rather small, just about 50mm square. There are no other pieces at this time at the IWM that would justify such statements like "...there is no evidience of back strokes or brushing out..." or "The width of the strokes was also fairly constant and would indicate the use of a brush approximiately 8 cm wide."

There is nothing at the IWM that would really indicate that these small piece are authentic. It is reported that a close examination of the fabric was carried out along with a chemical analysis that was attached to the fabric.

We have contacted the IWM on that and have asked for copies of these documents which we will post here in case we manage to get them.

In the meantime we will assume that the pieces are authentic 85 year old fabric that was indeed taken from 144/17.

The pieces held at the IWM can be described as follows:

A. Upper Side

On first glance it appears to be a unbleached linen (take a look at the flaked away paint at the outer edges) that was painted in a brownish color on which the olive green was applied. On top of that a almost completely flaked away clear coat was applied.

On closer examination it appears as having been done the following way:

1. The fabric was clear doped to tighten the fabric (No matter how many coats of dope).

2. A clear oil paint was applied that turned brown over the ages.

3. The olivegreen was applied over the clear oil paint.

My reason for this is the following:

When you take a close look at the strokes, you will note that the single streams are very thin and continious. This can only happen if one oil paint is applied on top of another in a wet in wet technique. The dope itself dries too quick to replicate this effect. If a paint is applied on top of doped fabric in this streaky way using a nearly dry brush, another effect can be seen. You can see this in our experiment. The lines of the strokes does not become that thin and continous, but interrupted and dotted. This is due to the irregular surface still at hand after doping due to the wooven surface of the fabric and the relatively "rough" surface provided by the dried cellulose which takes paint very good.

A complete cover of clear oil paint would provide a surface that would allow the green to appear in these very thin lines. The brown color was not intented but developed over the time, or was a result of the dryer added to to the oil paint.

B. The under side

When looked at it it clearly apears to be the same turquoise that was observed by Paul Leaman.

I doubt this was the way the paint actually looked and assume it was originally a light sky blue grey color.

I will explain this in my next post.

*

[AchimEngels]

This is my second post I promised.

This one deals with historical information and the continuing of my duration experiment.

First I want to make use of the content of a post by Laserlloyd in my thread on Voss`last flight. He posted a report on the salvaged wreckege of 103/17.

I want to quote directly from this report:

"Report on Fokker Triplane brought down by Lieutenant Rhys Davis.... Held in PRO File Air 1 Box 1061.

It is camouflaged green on the upper surfaces and sky blue on the lower"

In addition I want to quote the Apendix IV in the same post that gives another incident report by 2nd Lt. Barfoot-Saunt.

"The machine features a new attempt by the enemy at camouflage. The entire upper and side surfaces are doped in various shades of green, blue and grey...lower surfaces are a greyish blue"

If these reports, which are provided as duplicates only, are genuine they do well support the assumption by the FTS that at the time the triplane came out, Fokker used to apply the color scheme in the way we described above, by applying two streaky coats of paint, one light bluish grey (underside paint) and one olive green upper side paint on top of the clear painted fabric. This resulted in the various shades seen and reported by 2nd Lt Barfoot-Saunt.

This can also be clearly seen in several historical photographs.

Take the folowing for instance:


AEG license production at Fokker (image provided by Dave Watts)

This one was taken at the production facility at Lake Schwerin and shows the production of license built AEG aircraft at the Fokker plant. The various shades of paints applied can be seen clearly. For sure some will say there is no reason to assume the underside paint was also applied in the streaky manner on the top surfaces. *However, I can clearly see these shades of mainly three colors: linen natural color, underside light blue, green top color.

To illustrate the same thing in more detail let me attach the following images of another piece of our duration experiment.



You can clearly see the various shades of the resulting camouflage scheme.

Here is the same in b/w.



Although this is a digital image that for sure turns out different than actual films used at that time, you can clearly see asemiliar appearance than on the AEG image.

We will conduct further experiements with doped fabric pieces that have been first painted in a clear oil paint on which the streaky camouflage scheme was applied in a wet in wet technique to come closer to the pieces held in the IWM.

One may ask where the light greyish underside color is in the IWM pieces shown above. The answer is simple: it is not there. Just because this very small piece is taken from a area where no grey strokes have been applied.

The turquoise appearence of the IWM bottom side piece still needs some investigation, but the above contemporary reports contradict the fact that it in fact was applied as a turquoise.

Apart from that it is not a color the sky looks where you want to hide away something.

Best
Achim

[PeterL]

Good show Achim. I carried out a similar experiment several years ago, but far less scientific and on a much smaller scale. I shall be very interested in the results.

[Laserlloyd]

Here is the report that talks about the streaks in the fabric at different locations.

[ftp]http://www.osamalet.com/docvoss.jpg[/ftp]

Lloyd...

Good morning, Achim,

First off, I think this community is indebted to you and Dave Watts for finally making these rare pieces of fabric available to the wider public for inspection and consideration. I appreciate both your efforts in bringing these into the light of day, thus permitting everyone a better opportunity of judging their importance and of what has been written and said about them by other researchers.

Concerning the topside piece, the most striking visual aspect for me is the hue shift in the two shots (90 vs. 45 degrees). The effect is probably heightened by the difference in the “magnification” of the two views.

The second thing that I find striking is the size of these fragments that you report, nerely some 2 inches square.(50mm square). If the brush size was approximately 80mm, then it is quite clear that the sample could very well represents merely one of the larger color bands typical of the streaky finish—in this case one of the darker ones. Any analysis of the hue variation visible in this swatch will therefore underrepresent the overall variation seen on the actual airframes of the periiod —as documented in the view of the AEG machines. I believe something of the converse is also true: Extreme close-up analysis misrepresents (in this case, overemphasizing) the actual effect observed at more “normal” viewing distances of 1 or more meters. Photographed at these ranges, I am convinced the sample would appear to be a nearly solid color approximating the solid appearance of the darker bands in photo 1035. Therefore, unless Leaman’s report from the ‘70s was conducted on a larger piece then available, the conclusions reached must be considered to be limited. They lead to reconstructions of the streaky finish like the Dr. I at the US Air Force Museum (attached) that is too uniform (and probably of the wrong color).

Third, in light of the contemporary Intelligence reports that you quote—as well as others--I think it is necessary to make the assumption that the sample has indeed aged and color shifted toward the brown. It seems to me difficult to accept that any contemporary observe could have mistaken or misstated this hue for anything green!

Fourth, again assuming the Leaman report was based on these remnants, the samples provide no evidence that the lighter bands of the streaky camouflage actually represent the underlying, clear-doped, non-overpainted fabric. Indeed , as you suggest, if this were the case, there would be surface texture differences that would not result in the “wet-in-wet” appearance seen in many photos. Additionally, the Intel reports do not support there being “bald” (linen) areas, particularly of a creamy hue as seen in the USAF Museum triplane.

continued