Aotake - Part One

What Is It?

Following on from previous articles exploring interior colours is this brief diversion, hopefully of interest. There are several proprietory hobby paints available which purport to represent the translucent blueish-green protective coating seen on the interiors of both Army and Navy aircraft which has become well known as 'Aotake' (or aodake, 青竹). However, being essentially opaque metallic colours these paints can only create an approximate impression of the appearance and are often quite garish. Most modern translations describe Aotake as "green bamboo", the Nihon Kokugo Dai Jiten of 1972 defining it principally as "the trunk of raw, green bamboo", but the word "Ao" can be problematic in terms of meaning blue or green.

The niceties of the language were explored in depth in a superb article in the late and lamented Asahi Journal Vol.2 No.4 where two uses of the term were identified and explored, distinguishing between its use to describe a coating and its use to describe a colour. In the article Model Art 272 (Camouflage & Markings of the Imperial Japanese Navy Fighters in WWII) was reported to describe a green-yellow paint colour chip on page 109 in the following terms:-

"Ordinarily it's called aodake colour but actually it is a coating from a family of transparent zabon enamels. There are two branches to it, a blue one and a green one."

This chip is approximately similar in hue to FS 34258 but a little lighter and "metallic" in finish.

Model Art Special 329 (Camouflage & Markings of Imperial Japanese Army Fighters, 1989) went further:-

"Aodake is a crystal that dissolves in alcohol and is used in coatings when assembling steel and the like. (The aodake) used for interior colours was a transparent blue colour of zabon enamel but sometimes there were green ones too. When applied in coats it becomes an ordinary dark blue colour."

The strong dark blue pigment Prussian Blue (sRGB 0, 49, 83, very close to FS 15050 @ 1.14) was used in a similar way and was often referred to as "engineers blue". Aha, that is a rather deep, navy blue.

In Model Art Special 406 (Camouflage & Markings of Imperial Japanese Navy Bombers in WWII, 1993) the two apparent uses of the term were clarified:-

"Aodake used to be considered very similar to the zinc chromate (paint) on American and other military planes but the coatings were not of one type (only). There were Aodake Number One, Aodake Number Two and some other kinds. This light green colour of aodake was widely employed."

Many years ago Don Thorpe was adamant that the term aodake originally referred to the various opaque yellow-green interior paints. In a letter published in 1980 he stated:-

"Now, as to the transparent colors; aoitake is NOT a generic application for the bare metal primers. Aoitake was only referring to the opaque paints. The bare metal primer coating was usually applied at the point of fabrication of the sheet of metal or sub-assembly and was only intended to protect the rather rich mixture of aluminium alloy from the elements until such time as permanent coatings could be applied.

"I have mixed feelings on the subject of colors in this area, although I have encountered both blues and greens. I have also encountered samples of aircraft which had other pieces of metal attached, which when separated showed a bright blue in the previously covered area, and bright green in the previously exposed areas. One theory of this phenomenon is that when exposed to sunlight, fumes, salt air and water, etc., that the colors become fugitive and change hues. I have seen many examples of this in other Japanese aircraft so the theory is not without precedent."

This appraisal is strengthened by the impression of colour given by the term aodake shoku (green bamboo colour) to the Japanese layman, as demonstrated in the Asahi Journal article by the choice of green-yellow and green-olive hues to represent it. Thus was concluded a distinction between aodake as a coating, and aodake shoku as a colour.

In his seminal works on Japanese colours, Don Thorpe gave Munsell 2.5B 4/6 as the colour value for Navy/Army 'Translucent Blue' N16/A18, equating to sRGB 0, 108, 125 and FS 15125 @ 5.37 (so not very close - the FS value is insufficiently green in appearance). And for 'Translucent Green' as Munsell 5BG 3/6, equating to sRGB 0, 84, 82 and FS 34058 @ 10.0 (a poor match, too dark and not green enough).

In his most recent profile on the Ki-44 Shoki fighter, leading Japanese researcher and author Shigeru Nohara comments that:-

"This interior paint commonly called "Aotake" for the corrosion prevention was applied on the Ki-44 production aircraft until mid-1943. The paint was used by the Army and Navy but the name Clear Pale Blue was from the Navy. There are variations for this paint existed such as #1 and #2. Since the colour being translucent the tone after painting also depends on the repetitions of the coating."

The printed chip provided in the book is approximately similar to FS 34241.

Hobby Paints

As mentioned the aodake coating has been represented by a number of opaque metallic hobby paints. The GSI Creos (known as 'Gunze') Aqueous paint represents this coating with H63 'Metallic Blue-Green' which strongly emphasises a bright blue rather than green. The corresponding 'Mr Color' lacquer paint is C57. In Xtracolor the coating is represented by X355 'Japanese WWII Interior Blue' . Recent tins of this paint appear to be slightly lighter and more silvery than earlier examples. White Ensign Models Colourcoats paint ACJ15 'Aotake' is almost identical in appearance to the Xtracolor paint, perhaps chromatically just a little stronger. In the old AeroMaster Warbird acrylic colours was 1084 'Aotake', very similar to the GSI Creos paints. Lifecolor market an airbrush paint called "Blue Aotake" which has an advertised RGB value of 0, 144, 121 and is a very bright turquoise blue-green with no comparable Munsell or FS equivalents.

Representing Aotake

Correspondent "No Parachute" kindly contributed these images of his 1/32nd scale Hasegawa Ki-44 Shoki (above) painted using his own technique for representing this elusive finish. He begins with a base coat of Mr Color #159 'Super Silver' as "an excellent metallic color having the appearance and durability of actual metal". Then he mixes his own version of the 'green/blue' using Vallejo paints AV #70938 'Transparent Blue' and AV #70937 'Transparent Yellow' (FS 38907) to achieve the very pleasing result shown here. The finish is shown under various lighting conditions but at the time the photographs were taken was not clear coated. "No Parachute" welcomes comments on this finish - as do I.

To be continued . . .

Image credits: ©2010 "No Parachute"; Relics courtesy of Mr. Honma Hiroshi, Hokkaido Museum of Climate, Kutchan.

Useful Colours ~ Army Interiors Part One

"A little learning is a dangerous thing" said Alexander Pope. Well in modelling terms it is probably not dangerous - perhaps just misleading and rather irritating. Perhaps for modelling purposes Amos Bronson Alcott is more succinct: "To be ignorant of one's ignorance is the malady of the ignorant". Mr Alcott's observation is vindicated online on an almost daily basis and it often seems that those most afflicted with the malady are the most persistent imparters of opinion and information.

One of the most prevalent outcomes of "a little learning" is the dissemination of information in diluted or misunderstand forms which then become modelling conventions. There really does need to be a distinction drawn between the freedom to paint one's model whatever one likes and the sometimes unstated implication that the choice represents an outcome of research intended to impart "a little learning" to others. By such dubious means we have a generalised belief (reinforced by hobby paint companies) of aotake as a metallic blue-green paint applied in all Japanese aircraft cockpits and Luftwaffe sandgelb used by Kawasaki to paint the interiors of all their aircraft.

In Army form 'aotake' was introduced as a translucent dark blue primer for the interior of aircraft by the Army aircraft painting regulations of 3rd March 1932 (that is the Army painting regulations - once more - the Army painting regulations). It was not metallic per se but the application of the clear blue to bare metal surfaces no doubt gave (and gives) that impression. On 5th February 1936 the regulations were revised and the use of aotake (青竹色 - literally blue green bamboo colour - or sometimes written as 淡青色透明 - literally thin, translucent, light blue colour) was replaced by a dark greyish blue opaque primer paint which became colour standard #3 Hairanshoku or Hai-Ai-iro (灰藍色 literally ash indigo colour e.g. a greyish blue) in the Army colour standards. In practice this new paint was usually applied to internal crew areas whilst 'aotake' continued to be applied to other internal areas. Was #13 Ao iro ( 青色 - blue colour) also applied to some cockpits, either in error or expediency? Maybe.

There are two clues to the appearance of this colour standard. Firstly the actual Hess-Ives values used to measure the authorised range of hue in the procurement of Army paint supplies and secondly a pre-war French colour card which illustrates the colour and explains its use. Was there a connection between the French bleu nuit (night blue) interior colour and the Japanese interior colour? Perhaps. There is also another thing to bear in mind which is the distinction to be drawn between the colour standard and the actual paint supplied and applied. The two are not invariably the same. The promulgated colour standard displayed a variable and authorised range against which the paint suppliers (or more usually aircraft manufacturers) attempted to match. This distinction does seem to be misunderstood or perhaps under-appreciated.

In Methuen terms the median standard colour is a dark greyish blue between 23 E-F 5. The closest standard Munsell notations are between 2.5 PB 3/2 @ 2.98 and 2.5 PB 3/4 @ 2.40. The closest FS 595b value is 25053 @ 3.61 (but too blue), but 26118/36118 @ 7.02 (too grey) is often cited and indeed may provide a better scale impression although it is not quite blue enough. (A comparison value of 2.0 or less equals a close match). Ken Glass kindly advises that a reasonable out of the bottle match is Pollyscale RLM 24 Blau but it may need to be lightened with white and/or toned down with grey to match the swatches. 

The survival of badly weathered remnants of this paint in cockpits can give rise to a misidentification as aotake, but in practice diluted #3 spray or brush applied is not dissimilar in appearance. Aircraft interiors known to have been painted to #3 standard are Type 91, Ki-27, Ki-21, Ki-36, Ki-43, Ki-44 and Ki-48. Ichiro Hasegawa described the interior of a Ki-55 ('Ida') as having been painted in two colours, one being the bluish grey and the other a yellowish grey-green (the latter colur will be examined in Part 2). He also described the interior of both the Ki-21 ('Sally') and Ki-27 ('Nate') as being painted in this bluish grey which created a "gloomy impression", even the gunners mats being painted the same colour.The use of this colour continued until the introduction of new requirements on 15th June 1943 - of which more anon.

One of the aspects of the study of Japanese aircraft that continues to surprise me is the inability or perhaps unwillingness of some to reconcile the known (and published) Army colour standards with the extant appearance of paint on artifacts. It sometimes seems as though an element of being in denial exists, as though somehow the Army colour standards are not real and an opinion about a 65 year old fragment of paint without antecedence or provenance is more reliable. Hopefully one day we shall be able to move on from a quasi-religious veneration of the paint fragments to a broader and more equivocal appreciation of all the evidence.

Once this mini-series on interior colours is complete I intend to make it available as a pdf with appropriate hobby paint mixes which we are working on.

Image credits:- Ki-21 crew © 1942 Front Magazine; Colour chips © 2009 Straggler

Aotake Update

When I blogged about aotake in February 2010 here I quoted from Model Art 272 as follows:- 

"Ordinarily it's called aodake colour but actually it is a coating from a family of transparent zabon enamels. There are two branches to it, a blue one and a green one."

By way of further clarification "zabon" or buntan (pomello) is a type of Asian citrus fruit like a large grapefuit. I don't think the enamel was extracted from that or used an extraction from that in the coating (!). I believe the author was referring instead to Zapon lacquer which originated from a trade name applied to a cellulose nitrate varnish with a solvent which contained amyl acetate, butyl acetate and propyl acetate. This was patented in 1887 and marketed by the Celluloid Zapon Co of Springfield, NJ. Zapon lacquer dried to a very thin and transparent film and was originally sold as a varnish to protect polished metal parts. Zapon subsequently became a generic name (like Hoover for vacuum cleaner) and was marketed in various forms during the 1930's as a protective varnish.

The use of phenolic resin in the varnish results in a harder and more durable protection and in combination with tung oil produces the most water resistant varnish. The phenolic resin component tends to amber more significantly with age than alkyd resin based varnishes.

The addition of colour tinting to a metal protective transparent varnish (透漆 touru shitsu) aids in practical application and that chosen for aotake had its roots in traditional urushi based varnishes applied for the protection of armour. Aotake 青竹 in this application typically used 10-40% of dis azo, 0-50% of titanium oxide (white) and 10-20% phtalocyanin. Dis azo is from a family of water insoluble dyes (Azo pigments) of great chromatic strength and usually associated with yellow, orange and brown. Phtalocyanin is an intensely blue-green pigment. Sometimes orpiment (Sekioh 石黄) a yellow pigment, and indigo, a dark blue pigment, were used instead of the disazo dye and phtalocyanine in lower grade applications. There is a degree of yellow-blue-green variance inherent in the constituent proportions and in the way the coating ages.

The description 淡青色透明 (literally "thin blue colour transparent and bright") appears in some Japanese aircraft books to describe aotake, including those on JAAF subjects,  but it was more commonly used in an IJN context - as in the Zero-Sen technical manual for example. This is also sometimes written as 淡青色 (thin blue colour) but often translated, incorrectly, as light blue colour. The character 淡 tan means thin, faint or pale in the sense of low saturation or weak chroma rather than bright or light which is 明 mei. 

As to lacquer and enamel these have been subject to various definitions but the USAAF HQ ATSC Dictionary of Aircraft Maintenance Terms (T.O. No. 30-1-2-H) Section H Paint and Dope published in November 1944 defined them as follows:-

"Enamel - a special kind of paint in which the vehicle is a drying oil or a combination of drying oil and resin. It dies to an even, hard, permanent finish. Usually it yields a glossy surface, but addition of a flatting agent can cause it to dry flat. The term is often used to mean a pigmented varnish. In aircraft work a synthetic enamel which dries quickly with a high gloss is often used."

"Lacquer - A solution of film-forming materials in a volatile solvent, used chiefly for decorative purposes. There are several types of lacquer. The most important in aircraft work are the "cellulose lacquers" which have a nitrocellulose or pyroxylin base, to which pigments, resins, plasticizers, solvents and diluents may be added. Other kinds of lacquer have a resin (synthetic or natural) base, dissolved in some solvent such as alcohol. Lacquers dry relatively quickly, chiefly by evaporation, leaving a tough, flexible, lightweight film. They cannot be used over oil-base paints, for they contain solvents which cut such paints. They may be applied either by spraying or brushing."

Image credits: Web

Useful Colours ~ Army Interiors Part Two

After running the first part of this series a couple of beautifully made big scale Ki-44 models have appeared built as on-line and magazine reviews where the primary source evidence from the 'Rikugun kokuki tosou kitei' is disregarded in favour of opinion and/or the ubiquitous internet research. This resulted in the cockpits being painted in a beautiful metallic blue ersatz 'aotake' in one case and a home-brewed bright apple green in another (based on a verbal description of colour from the memory of someone about a different type of aircraft). Lovely to look at these colours and again no problem whatsoever with the personal choice. But big problems with the fact that they were being promoted as any kind of informed choice - other than that of the "nobody really knows" type.

The requirement to paint cockpits dark blue-grey lasted until mid-1943 whilst the Type 2 was being manufactured (in all forms, including prototype) from August 1940 to January 1945. There is a clue therefore that a goodly proportion of the type up to and including mid-production were probably finished to comply with the requirements. This takes the possibility of a dark blue-grey interior into the realms of the coded serials batch 1271-1309 manufactured during June 1943.

The revised 'Rikugun kokuki tosou kitei' (Army aircraft painting regulations) of 14th June 1944 ordered the use of JAAF paint standard colour # 7 Ohryoku nana go shoku (黄緑七号色 - yellow green no.7 colour) for the painting of the upper surfaces of all Army aircraft including the cockpit interior and drop tanks. It also discontinued the requirement for the dark blue-grey and 'aotake' primer on other internal parts of the airframe in the interests of expediency. These instructions were not implemented immediately and factory painting of most types did not begin until August or September 1944, and even October for the Hayate production lines.

'Ohryoku nana go shoku' is perhaps one of the least understood and potentially most confusing of the JAAF paint colour standards, even causing a long puzzled Shigeru Nohara to state his preference for describing it as "dark khaki brown" - and ignoring the official designation - in his recent monograph on the Ki-44. In the past it has also been referred to as "late war brown", "deep brown green" and "Homeland defence khaki" - all intended to be one and the same colour - or perhaps more accurately the same colour standard. These descriptions tend to conceal the strong olive green chroma that was prevalent in the colour standard, although the procured and applied paint varied as we may see. In practice the permitted range of this colour imitated US Olive Drab but is perhaps best described as an olive brown, extending from a deep brownish olive green to a drab khaki brown. In colour terms the range is from Munsell 2.5 Y 3/2 to 7.5 Y 3/3. The closest FS 595b equivalent to both these values is conveniently 33070, @ 4.69 for the "brown" 2.5 Y 3/2 and 2.37 for 7.5 Y 3/3 (the slightly different readings above relate to the difference calculation between the respective pure sRGB values). Therefore this FS value is biased towards the greenish end of the range and 33070 is not quite brown enough for the brown end of the range. The bright orange and reddish browns that appear on some models (and profiles) intended to replicate this "late war brown" are largely flights of fantasy.

Conducting an online search for yellow-green colour (黄緑色) in Japanese language clarifies Nohara-san's confusion, because it will bring up many images of what can be described as a pea green colour - a strongly yellowish green. These are similar to the sickly yellow greens of JAAF # 29 yellow green colour (also 黄緑色 but often romanised as ki midori iro). This potential confusion may explain the qualifier No.7 (七号) always used to differentiate the olive brown colour.

Extant artifacts and paint surface colour measurements confirm that # 7 was applied inside cockpits on several types (such as the Ki-45 and Ki-67). However, whether there was some confusion in the understanding and implementation of this order or in its intention, another JAAF  # 29 yellow green is also found inside the cockpits of Nakajima Ki-43, Ki-44 and possibly other aircraft, particularly during the mid-war period (so the practice might have preceeded the June 1944 instruction). The measurement of one example of yellow green from the interior of Hayabusa 5227 matches this colour almost exactly. The closest Munsell equivalent is 10 Y 4/4 and the closest FS 595b match to that is 34151 @ 2.15 (but not quite yellow or chromatically strong enough). Curiously the latter FS value has also been cited in respect of Mitsubishi-built Zero cockpit interiors. This interior colour has been described variously (primarily in Hayabusa cockpits) as a "Nile green", "sickly green","yellowish olive green" and "bilious green". A dull and weathered version may be the basis for the "khaki green" suggested by Hasegawa for its 1/32nd Shoki model but there is no way of knowing if this suggestion is for a variation of # 7 (and I have not checked out the hobby paint colour cited). Early 1960's representations of a distinctive "oily green" finish on the cockpit, wheel wells and the inner faces of the undercarriage doors on Shoki may be attempts to depict variants of # 29.

A recent theory supposedly emerging from Japan, that during the early period of the war Army cockpits may have reverted to an aotake finish  (青竹色 - literally blue green bamboo colour - or sometimes written as 淡青色透明 - literally thin, translucent, light blue colour), seems to be based upon the evidence of paint colour in the restoration of surviving Hayabusa s/n 750. The available documentation about the restoration (excerpted below) is somewhat ambiguous and, bearing in mind the official instructions and previous comments about how degraded examples of # 3 can appear to the eye and not taking single examples as proof of a standard methodology, this theory seems a little tenuous.

"A full surface corrosion removal (of Hayabusa s/n 750) was undertaken. Fortunately corrosion had not got a good hold on this aircraft and most was buffed off using Scotchbrite buffing wheels. The wash also brought the internal corrosion proof paint up beautifully. The colours inside now were brilliant green with some blue panels, and where it had not been exposed to ultra violet light, had proven itself to be extremely effective in its performance. The interior skins were remarkably well preserved. We were able to duplicate the colours fairly accurately and decided that a deoxidene and alodeine wash would be appropriate before any new paint application to ensure future preservation of the original skins. Later in the year areas which did show surface corrosion were buffed to remove corrosion and the above washes were applied before the final paint." 


"Inside the flap bays, the corrosion inhibitor again had served the Oscar well, the translucent green protecting against deterioration and this required no rework at all apart from cleaning. It is of interest to note that internal skins inspected were hand numbered 750, from time of manufacture as were the fuel tank bays. "


Gakken 52 on the Hayabusa states that whilst the prototype and pre-production versions of the Ki-43 had the cockpit interior finished in ash indigo colour, (hai ran shoku or hai ai iro 灰藍色) the production aircraft had the whole interior, including the cockpits and wheel wells, finished in aotake.

Majoring on the Ki-44 for the time being, which seems to be the flavour of the month, we do have some interior photographs to consider. The cockpit photographs of s/n 2143, captured at Clark (and manufactured during October 1944), are fairly well known, but a new Japanese photograph, of the port side of the cockpit of another Ki-44 with the pilot's gloved hand on the throttle, appears on page 33 of Scale Aviation # 70 (Nov 2009). Now, I am not about to attempt that dark and fallacious art of interpreting colour from monochrome photographs, but at least the paint surface may be seen to be darkish in tone and opaque in character with the usual chips and scratches suggestive of a conventional paint finish subjected to the trials and tribulations of service use. There is not the barest hint of the brightly reflective, translucent, metallic-looking surface finish suggested by the restorations of Hayabusa s/n 750 or the NASM J1N1-S Irving.

My penchant for believing in the viability of early references, in preference to some of the revisionist and opinionated twaddle aired on the 'net these days, is well known - and well scorned. But the fact remains that in the thirty years period after the war there were very many more people around who had actually lived and worked up close with the equipment we now ponder. They were not grizzled ancients either, but men and women in their prime, and they were more accessible then than now, still being of working age and to be found in establishments and institutions throughout society, and able and mostly very willing to answer questions - if and when asked. I'm not suggesting that all references in this time period should be viewed without question or accepted unchallenged without the confirmation of other evidence, but I do believe it is equally wrong to treat them all as somehow primitive and unreliable. That being offered in Maru's 1978 painting of the Shoki interior depicts an opaque green of somewhat indeterminate character, a true 'aotake' in the early understanding of that colour as a "fresh bamboo green" opaque paint. The colour is not quite yellow or bilious enough for # 29, or olive and brown enough for # 7, but I would have no hesitation in using it as the basis for painting a Shoki cockpit. In fact my own pecking order, included for interest rather than mandated in any way, would be as follows:-

1. Dark blue-grey, # 3, for early and mid-production examples

2. Yellowish olive green, # 29 for mid-production to late-production examples

3. Olive drab, # 7, for late production examples

4. Translucent yellow-green aotake as a possibility on some mid-war examples.

5. Blue aotake.

The last part of this series will explore the colours specific to Kawasaki manufactured aircraft.

Image Credit: Rendered colour chips ©2009 'Straggler'

Vallejo IJA Colors Set ~ A Visual Appraisal & Commentary

The Spanish hobby paint manufacturer Acrylicos Vallejo, S.L. have recently released two sets of acrylic paints in their Air War Color Series intended for Japanese aircraft. Art.71152 is a set of 8 paints for 'Imperial Japanese Army (IJA) Colours Pre-War to 1945' consisting of the following colours:-

1. IJA Dark Green AV71285
2. IJA Olive Green AV71286
3. IJA Khaki Brown AV71287
4. IJA Dark Beige AV71416
5. IJA Grey Green AV71326
6. IJA Light Grey Green AV71321
7. AOTAKE Trans.Green AV71417
8. Aluminium AV71062

The paints are reportedly intended for airbrush use but have a surprisingly thick viscosity. They come in Vallejo's familiar plastic 'eye-dropper' bottles in an attractive carton featuring a colour photograph of a restored Ki-43 Hayabusa in flight over chips of each paint colour which apart from the aotake are pretty close to their actual appearance, a guide with profiles (shown below) and a brief explanation of the usage of each colour with FS 595 equivalents. Inside the box is a folded leaflet showing the Vallejo paint range.

The first point to note is that some of the Vallejo colour descriptions do not correspond to any official paint colour designations in the IJA KôKaku 39 colour standards. This makes it more difficult to reconcile them without direct comparisons and tends to perpetuate the imprecise understanding of the colours fostered by previous hobby paint ranges.  The second point to note is that this is a preliminary visual and subjective appraisal of painted out samples which have not yet been measured for their precise colour values and it does not take into account any long term curing and colour shift of the paints. There may be updates! A commentary on each paint colour follows.

IJA Dark Green AV71285 - This is similar to the generic IJA Greens in other paint ranges and is compared by Vallejo to FS 34082 which appears lighter and greener. It is a dark, dull olive green and not typical of the stronger greens offered in other paint ranges to represent the so-called 'Nakajima Green' for example.  It approximates # 22 Noh Ryoku Shoku (濃緑色 - deep green colour), but is a little lighter. Probably more useful as a variant of the late war IJA # 7 as applied to some Kawasaki types. 

IJA Olive Green AV71286 - This is meant to represent the late war # 7 olive drab colour and is compared to FS 33070. It is darker and slightly more brownish than the Dark Green AV71285 but slightly greener than FS 33070. It has a good richness of hue.

IJA Khaki Brown AV71287 - This is described as another late-war colour and compared to FS 30118, although it is slightly darker and more greenish. It is similar to the late-war factory paint, a variant of # 7, recorded by Noboru Shimoune as applied to Mitsubishi aircraft like the Ki-67 and Ki-46-III.

IJA Dark Beige AV71416 - This is described as a camouflage colour used in conjunction with Dark Green or as a single upper surface colour and is compared to FS 30215. It is close in appearance to the seventh chip in the Model Art 329* colour chart and described there as cha iro (茶色 - 'tea' colour, light brown or tawny):-

"This colour was used in conjunction with deep-green as a camouflage scheme at the beginning of WWII. Many of the Nakajima Ki-43 "Hayabusa" (Oscar) and Nakajima Ki-44 "Shoki" (Tojo) were camouflaged in this two tone scheme or simply spotted with the deep green over the brown." 

and

"This colour was used on aircraft over the China front. It resembles the colour of the ground surrounding the Yellow River in northern China. It was yellow tinged with tea colour."

Not really typical of the official IJA colour standards for browns which do not use the term "beige" (katakana: ベージュ beeju), dark or otherwise, but similar to many artistic depictions. It has an appearance between the 'orange-brown' of  # 33 Kaki iro (柿色 - persimmon or shingle colour) and the dark earth of # 31 Cha Kasshoku (茶褐色 - ‘tea’ brown colour, dark reddish-brown or liver colour), closer to the former than the latter. Therefore it perhaps has a certain hybrid/generic usefulness as a simplification to avoid head scratching when pondering black and white images to decide which brown! "More tea, vicar?"

IJA Grey Green AV71326 - This is a distinctly creamy or brownish grey which is compared to FS 36405 and is similar to the late-war factory applied under surface paint on types like the Tachikawa-built Ki-43-III Ko and Nakajima Hayate. It would also be useful to represent the creamy grey reported on some Ki-27 training aircraft. The Vallejo paint is just slightly more brownish than 36405. 

IJA Light Grey Green AV71321 - This is similar to generic IJA Grey Greens in other paint ranges and is compared to FS 34424. It is close to the first paint chip in Model Art 329 which is described as hai ryoku shoku (灰緑色 ash green colour), but more greenish than the # 1 colour standard for that colour and as the FS equivalent suggests, similar to the RAF colour Sky. The IJA colour standard sits more typically between the two Vallejo colours so there is an opportunity to mix them to achieve different effects.

Neither of the grey greens in the set represents the more blueish-grey colour seen on some Army types.

AOTAKE Translucent Green AV71417 - This is a surprisingly bright emerald green colour and not typical of the more subtle blue or blue-green hues of real aotake. No FS equivalent is given but it is similar in appearance to FS 14193. It is the only colour which does not look similar to the chip shown on the box. Probably the least useful colour in the set.

Aluminium AV71062 - This is a bright aluminium somewhat between a polished and oxidised natural metal finish.  Impressive for an acrylic paint.

Vallejo IJA paint colours shown by their cited FS equivalents ~ the actual paint colours vary slightly

Like the curate's egg this paint set is good in parts and worth considering for those who like to use acrylics and find Vallejo paints suited to their use. I found it potentially more useful than expected after seeing the colour descriptions and before being able to examine the actual paints. The colours have an attractively subtle and sombre "military" quality that should look good on models in contrast to the brighter national and unit insignia. It is a pity that the designers strayed from official designations and that the aotake and aluminium colours were included in preference to some arguably more useful camouflage colours such as # 21 or # 30. In the UK the cost of the set works out at about £2.30 per paint bottle but I don't know if the paints are yet available separately or will be. The appraisal set was purchased from Everything Airbrush (The Spraygun Company Ltd) in Poole, Dorset.   

Appraisals of the Vallejo IJN and AK Interactive IJN sets to follow. . .

Update: In respect to issues of viscosity and application Ken Glass has since kindly provided the helpful advice that Vallejo Thinned Medium VJ70.524 will ease brush painting and improve levelling. 

* Camouflage & Markings of Imperial Japanese Army Fighters, Model Art No.329 (1989)

Image credit: All © 2017 Acrylicos Vallejo, S.L.

 

 

 

  

Aleksei Kryukov's Hasegawa 1/48 85th Sentai Ki-44-II Ko “Shoki” ~ Part 2

Here is the continuation and completion of Aleksei's description and photographs of his superlative Hasegawa Ki-44 build.

Landing gear doors, struts and wheels  

"The insides of the landing gear doors supplied in the kit are more appropriate for the later marks of Ki-44-II since they lack the ribbing. The original parts were rather thick, so I scratchbuilt the new ones from sheet aluminum. The process was as follows:

• New doors cut from sheet aluminum using original parts as templates;
• Riveting added with a needle and lower parts were bent into the proper shape;
• Ribbing was imitated with thin stripes of plastic glued in place with epoxy glue;
• Original kit smaller doors were thinned, riveted and detailed with retraction rods from wire and plastic;
• Oleo rubber covers’ folds were deepened with a thin file, oleos detailed with photoetched parts and wiring (fixed by superglue and rings made of foil stripes);
• Tubes on main wheel disc covers were cut off and made from scratch using pieces of wire with flattened ends. 

"After the fuselage halves and wings were glued together I slightly detailed the tail wheel well (anyway not much will be seen through the closely fit doors). Tail wheel doors were scratchbuilt similarly to the landing gear doors, i.e. cut from aluminum and detailed with plastic. Tail wheel fork details were deepened with a blade.

"After that additional detailing followed: scratchbuilt landing light, adding photoetched grills, rescribing some panel lines, deepening elevator, aileron and rudder hinge lines, adding some access panels from foil, deepening the exhaust outlet and thinning its walls; adding pitot from fine tubing, building antenna mast from a needle, adding wiring to the gun sight, using syringe needles in place of cowling machine guns, drilling out wing guns’ barrels, detailing headrest with photoetched parts and plastic, filling out 3 holes in the headrest and drilling out 4 new ones.  

"Canopy fit to the fuselage is below average so a lot of trimming was required. It was sanded, front part was glued in and seams filled with superglue. Silicon molds were formed on the leading edge lights in order to make copies from transparent epoxy with some color paint added. Oil radiator housing was modified (plastic walls thinned to scale, grills added). Model was riveted on top of the primer coat. 

Painting and weathering

"Except for stencilling on the control surfaces few of the kit decals were used. Himomaru, stripes and various fuselage elements as well as control surfaces were airbrushed with proper colors and masked off. The following paints were used:

• Hinomaru: GSI Creos (Gunze) Mr. Color 3 Red
• Wing and propeller warning stripes: GSI Creos (Gunze) Mr. Color 58 Orange Yellow
• Control surfaces: GSI Creos (Gunze) Mr.Color 128 Gray Green
• Propeller: GSI Creos (Gunze) Mr.Color 131 Propeller color

"Wheel wells were first painted aluminum; square masks were placed over some holes, followed by a coat of aotake - GSI Creos (Gunze) Mr. Color 57 Metallic Blue Green). Strictly speaking wheel wells could also be painted the cockpit color (blue-gray), but I really wanted to paint them in aotake. One more argument in favor of aotake is the fact that aforementioned Shoki wreck in China shows remnants of aotake inside the wheel wells.   

"The model was given a coat of GSI Creos (Gunze) Mr.Color 8 Silver and several layers of Alclad. Before spraying the camouflage colors thin masks of scotch tape were added around hinomaru and anti-glare strip. I used GSI Creos (Gunze) Mr.Color 129 Dark green (Nakajima) for the green mottle and the brown blotches were mixed from Tamiya acrylics XF-78 Wooden Deck Tan, 64 Red Brown, and 68 NATO Brown).

"After painting smaller details with a brush, the model was given a flat coat of Akan (a well known Russian producer of authentic paints). The post shading and weathering effects were achieved with airbrushing, Mig pigments and oils. Alluminum scratches were painted with a thin brush using Tamiya enamel. Akan semi-flat was used for the finishing coat. 

"After the final assembly (leading edge lights, antenna, etc.), minor corrections and toning surface with oil the construction was finished. 

"Unfortunately I couldn’t avoid some mistakes. For instance the formation light on a rudder should be transparent. Air scoop above the engine is left blanked off because no reliable information regarding this part could be found."

Aleksei Kryukov

Image credits: All images © Aleksei Kryukov via Iskender Mailibayev 

  

Vallejo IJN Colors Set ~ A Visual Appraisal & Commentary

Following on from the appraisal of the Acrylicos Vallejo, S.L. IJA paint colours set, Art.71169 is a set of 8 paints for 'Imperial Japanese Navy (IJN) Colours Pre-War to 1945' consisting of the following colours:-

1. IJN Dark Black Green AV71325
2. IJN Black Green AV71322
3. IJN Deep Dark Green AV71310
4. IJN Ash Grey AV71311
5. IJN Medium Grey AV71312 
6. IJN Medium Brown AV71418
7. AOTAKE Translucent Blue AV71419
8. Aluminium AV71062

These are also in plastic 'eye-dropper' bottles in an attractive carton featuring a colour photograph of an A6M5 Zero in flight over chips of each paint colour which are fairly close to their actual appearance, a guide with profiles (shown below) and a brief explanation of the usage of each colour with FS 595 equivalents. Inside the box is a folded leaflet showing the Vallejo paint range.

Again the Vallejo colour descriptions do not fully correspond to IJN paint colour designations. This makes it more difficult to reconcile them without direct comparisons and tends to perpetuate the imprecise understanding of the colours fostered by previous hobby paint ranges. A commentary on each paint colour follows. 

IJN Dark Black Green AV71325 - this is described as a one coat upper surface colour as applied by Mitsubishi over ash grey/medium grey or natural metal and compared to FS 34052. It is approximately similar to D1 Deep Black Green but lacks blue-green chroma and is more greyish.

IJN Black Green AV71322 - this is described as representing the upper surface paint of Nakajima-built Zeros and "all kinds of aircraft of other manufacturers", being compared to FS 34077. It is greener than the FS value but duller than D2 Black Green, lacking the blue-green undertone of the original colour. 

IJN Deep Dark Green AV71310 - on the way into green garden shed territory with this one which is described as the upper surface paint applied by Kawanishi and Aichi, being compared to FS 34058. That FS value is the closest to Thorpe's N2 Dark Green but not that close @ 3.99 (where < 2.0 = a close match), being more vibrant and blueish. The difference is shown below.

The two Vallejo Black Greens seem more typical of weathered and aged paint, described the wrong way round, with the colour attributed to Mitsubishi rather more typical of Nakajima and vice versa, although sources do differ on those assertions. The subject is explored in more detail in the AoJ  IJN Greens PDF. The Vallejo colours dry matt which adds to this perception, but they do become slightly richer in appearance with a gloss coat.  The Deep Dark Green is dodgy for reasons beyond the scope of this blog feature but Kawanishi Shiden and Shiden-kai colours were explored here in February and May, 2010, including interiors, but the subject is by no means as straightforward as any confidence in hobby paint sets might suggest! A Shiden colours PDF is scheduled for the AoJ Key Data colour series.

IJN Ash Grey AV71311 - described as the colour for "most embarked aircraft" and in use until 1942/43 it is compared to FS 36350, therefore close to the Mitsubishi Zero early factory colour, albeit just a little darker and browner than the FS value. It lacks the olive undertone of the original paint.

IJN Medium Grey AV71312 - this is compared to FS 36375 and described as used for lower and fabric surfaces. The actual paint is nothing like the FS value which is a slightly violet tinged light blue-grey but is a warmer, more neutral grey closer to FS 36357, so I suspect a typo or something lost in translation here.

IJN Medium Brown AV71418 - this colour is compared to FS 30122 and is similar to many depictions of the pre-war brown applied as camouflage together with dark green to the upper surfaces of IJN aircraft, particularly in the China theatre, but surviving into the Pacific War on types such as the G4M and some floatplanes. The precise hue of this brown is still a matter of conjecture and Japanese researchers have attributed it as H2 more by deduction than proof. The Vallejo paint is a medium to dark reddish brown but not as dark as the prop colour or as reddish as the primer paint.

AOTAKE Translucent Blue AV71419 - more typically blueish-green than the aotake paint included in the IJA set but still more towards green than blue. Although not compared to a FS value, it is similar to Thorpe's N17 Translucent Green.

Aluminium AV71062 - this is the same colour included in the IJA set.

 Vallejo IJA paint colours shown by their cited FS equivalents ~ the actual paint colours vary slightly 

Again something of a mixed bag. The two Black Greens both lack blue-green chroma and tend towards olive greens, which some might prefer but which are more representative of weathered and aged paints. The greys are uncontroversial unless you still believe in 'white' Zeros, but the so-called Ash Grey lacks the distinctive olive undertone of the original paint and the Medium Grey is closer to FS 36357 than FS 36307 which is associated with J3, 2-6 and the fabric dope. The Medium Brown is a catch all and will probably look good with Dark Green on the pre-war types whilst the aotake is more representative than that included in the IJA set. Colours aside, useability appears a matter of preference with some concerns expressed, but seemed to be of more interest than the colours themselves judging by the comments about the IJA set (!). This set was also purchased from Everything Airbrush (The Spraygun Company Ltd) in Poole, Dorset and is the same price as the IJA set.

Image credit: All © 2017 Acrylicos Vallejo, S.L.

   

Grey Blue Cockpit Interior in Ki-61

Hat tip to Lorenzo of Italy for kindly alerting to this interesting Japanese video footage clearly showing the grey-blue # 3 Ash Indigo colour (Hai Ran shoku - 灰藍色) in the interior of a Kawasaki Ki-61 Hien 'Tony' recovered to Japan from New Guinea. The colour is similar to FS 36118 Gunship Gray, ANA 603.

From 1936 the grey-blue paint was to be applied as an overall primer to replace aotake, sometimes with the addition of # 17 Faint Blue colour (Tan Sei shoku - 淡青色)  as a middle coat before the grey green # 1 Ash Green colour (Hai Ryoku shoku - 灰緑色) was applied to external surfaces in top coats, sanded and polished. The whole interior, including the cockpit, was to be painted the grey blue colour and this was introduced with the Ki-15, Ki-21 and Ki-27. In practice this continued for the cockpit into the war years, certainly for early production Ki-61, whereas aotake continued to be applied to other parts of the interior. When the application of aotake to interior surfaces was discontinued in early 1943 in order to to speed production cockpits began to be painted in other colours in a more haphazard manner, including the # 1 grey green and another darker grey green paint similar to that used for Hayate propellers.     

The grey blue paint was also found inside the wing sections of the hybrid remains of Ki-61-I Ko/Otsu c/n 379/640 (379 constructed in Sep 1943 and 640 in Nov 1943), although the wheel wells appeared to be painted in a lighter grey colour, unspecified. Whether the lighter grey paint was very badly degraded, chalked or faded grey blue is now impossible to say. The problem, as referenced before, is that restorers take an inconsistent approach to measuring and recording extant paint in surviving airframes, often just stating that new paint 'matches the original' without actual providing colour values for it, the original paint being destroyed in the process. And laying standard paint swatches against the original paint surface and photographing them is not a valid scientific method for identifying the original colour value(s). 

Update

Added some additional details of painting technique for the 11 March 2023 blog post featuring Guillermo's Fine Molds Ki-43-III Ko .

Ohka Kits & Colours

Fine Molds have recently released two 1/48th scale kits of the IJN 'Ohka' (桜花 cherry blossom) rocket propelled and piloted bomb, the MXY7 used for special attacks, usually dropped from a Mitsubishi G4M2 'Betty' bomber, and the K1 unpowered glider trainer. There have been previous kits  from Hawk (as 'Japanese Kamikaze Piloted "Baka" Bomb' and in a double kit with a German V1) and Tsukuda (a Hawk re-pop) said to be to 1/41 scale and Kora have released or are due to release a model of the later Ohka Model 22 in 1/48. A 1/72nd scale Ohka was included in the Hasegawa Mitsubishi G4M1 'Betty' bomber issued in 1969.

Tsukuda Ohka

A photo-etch sheet designed to be used with the new kit is also available separately from Fine Molds (!). At that price you might think . . . . It consists mainly of seat, seat belts, armour plate and other cockpit fittings together with a brass pitot tube.

The US authorities coined the Japanese term 'Baka' (馬鹿 fool or folly) to describe this weapon, said to be for propaganda reasons in order to downplay their concern at the Japanese suicide tactics. It always irks when  contemporary terrorist attacks are sometimes compared to the Japanese suicide attacks by ignorant (or lazy) media writers. The Japanese made those attacks as uniformed combatants, flying military aircraft against legitimate military targets in a theatre of war. This is not to forget or in any way to denigrate the many victims of the attacks, who were also soldiers, sailors and airmen fighting for their countries and doing their duty. And it is not to excuse or justify the war aims of the government that sanctioned them. The final writings of the special attack pilots reveal that many of them, far from fitting the popular stereotype of fanatics, expressed anxiety, sadness at the prospect of their premature deaths, concern for their families, an instinctive awareness of the ultimate futility of the enterprise but above all a deep sense of unavoidable duty. The peer and hierarchical pressure in their decisions to volunteer for these terrible missions are not to be underestimated. The young Japanese pilots who volunteered were servicemen responding to a rigidly imposed hierarchical militarism in which the concept of sacrificial death in battle and duty to their homeland was central. The Imperial Rescript to Soldiers and Sailors (軍人勅諭 Gunjin Chokuyu) issued by the Emperor Meiji in 1882 contained the precept that "Duty is heavier than a mountain; death is lighter than a feather".

I suppose it is possible to build a model of an Ohka and give no thought to the underlying moral and philosophical aspects, the distinction between an aircraft carrying a bomb and an aircraft designed as a bomb is perhaps a fine one, but for some it may be more difficult. Fine Molds have already released models of the "human torpedo" kaiten  - (回天 - difficult to translate "shaking the heavens") and midget submarines used for one way missions so the Ohka could be seen as a logical continuation of this theme. Ohka has a special resonance for me because at about the age of seven I sat in the cockpit of one overseen by my father who pointed out the sparse controls and how they worked. It was the origin of my interest in Japanese aircraft but the concept was, and remains, a chilling one.

TAIC Cutaway Drawing of Ohka

Hawk "Terror Attackers" Double Kit of Ohka and V1

Ohka Model 11 Colours

Leaving aside the difficult moral and philosophical dimension to focus on modelling this aircraft there is the perennial question of colours. Ohka is often depicted in the whiteish grey associated anachronistically with the early Zero or sometimes in a light green as with Hawk's kit. The Fine Molds kit instructions suggest overall GSI Creos (Gunze) Mr Color # 35 IJN Grey (Mitsubishi), which is a bright, slightly blueish grey of Munsell 4.7 B 6.5/0.5 (close to FS 36373 @ 1.26), conceived in the 1980's and purporting to represent the early Zero colour. However, a pale blue-green around Munsell 2.5 G 8/1 and 5 G 8/1 has been authoritatively reported from extant samples for the fabric covered plywood wings and tail assembly. The fuselage and metal parts are reported to have been painted in an "olive grey" (amber grey or yellow grey) around Munsell 5 Y 6/2 to 7.5 Y 6/2 similar to the early Zero. Some colour photographs and film (view from 1:09) do suggest that this is not simply due to thermal ageing of the paint surface although no doubt that might be a factor in the current appearance. The main reason for the yellowish caste of the "grey paint for light metal" is subject to much heated debate. The presence of yellow or yellowish-brown pigments in the paint is disputed but regardless of that the Urushi-type plant resins of amber character used in the binder had an immediate tinting effect on the white pigment and with the black created a fugitive greenish undertone. The fabric dope was of a different type, a pigmented cellulose acetate butyrate, the xharacteristics of which are that it is  clear rather than amber in tone and that it does not readily yellow with age.  

The colours shown above are those as reported in the linked article but it is perhaps best not to follow them too slavishly as the contrast between wings, tail and fuselage might be stark on a small 1/48th scale model. A more subtle difference between a cool, slightly blue-green grey and a warm, slightly yellowish grey will work better visually. A superb 1/72nd scale Hasegawa Ohka, displayed here demonstrates this more subtle effect. The two Munsell values cited for the metal paint are very close to each other @ 1.81 so the difference need not worry but there is no close FS 595B equivalent to this colour. The closest,  FS 33303 @ 3.26 & 4.98 respectively, is a poor match, being too brown in appearance and without the slight green or olive caste that is present. The closest FS 595B value to both blueish grey fabric paint values is 35622 @ 1.65 and 2.08 respectively, so a good match. Coincidentally this is the same FS value that is closest to the Du Pont MAP equivalent paint standard 71-021 Sky Type S Grey - a pale duck egg blue applied as an equivalent to Sky on early US manufactured aircraft exported to the RAF.

But by all means experiment and if you prefer an all-grey Ohka so be it. In terms of approximating the colours on a model Japanese modellers always seem more comfortable with the concept of absorbing the available data and settling on a personal interpretation of it - and accepting the inevitable differences between models without fretting over them or trying to impose their preferred solution on others. Western modellers on the other hand, appear more inclined to seek a "consensus" - that old impostor which can sometimes become the origin of a modelling convention that is flawed rather than factual. Too often the well is poisoned by "innocent" questions prefaced in the expectation of a "controversy" and/or containing their own half-arsed answers which leaves this pragmatist cold. Bearing in mind the arcane subject matter the bold and unequivocal statements sometimes made about colour on forums, as though Japanese (and other) aircraft were really painted in Tamiya or Gunze hobby paints, never cease to amaze - especially those gems that begin with "I don't know but . . . ".

Internally Robert C Mikesh reports evidence of yellow-green 'aotake' in the cockpit interiors of the three examples in the UK*, but bear in mind this appearance could be a shift from an original brighter blue-green or malachite. The seats, seat mount, canopy latch fittings, brace handholds and other steel  components were painted black, but the instrument panel was also 'aotake'. Note that this interior colour for the Model 11 is in contrast to the darker green opaque paint reported for the Ohka Model 22 in the same source and in Asahi Journal Vol.3 No.1 'Japanese Aircraft Colours at NASM'.

None of the ready made 'aotake' hobby paints achieve a really convincing appearance, often glaring out at the observer as modern metallic paint, and it  is better, if you have the patience, to mix the colour and apply it as a semi-translucent varnish over a bare metal finish as demonstrated here and also shown here. Scale and shadow does come into this though so the "gleaming" appearance of a 1950's Japanese robot on a small model is best avoided. For Humbrol users approximate 50/50 combinations of 88 Deck Green and 104 Oxford Blue, lightened slightly with 109 WWI Blue can be used to represent both the Army # 3 interior indigo grey and generic 'aotake', thinned as appropriate.

Note in this view the apparent similarity of fuselage, wing and tail colours

* Reported in 'Japanese Aircraft Interiors 1940-1945' (Monogram Publications, 2000)

Image credits: box art © 2011 Fine Molds; box art © 1958 & 1960 Hawk & © circa 1980 Tsukuda ; model images © 2011 Fine Molds; TAIC drawing net; film stills author's collection; rendered colour chips © 2011 Straggler; colour photos net.