Thursday, 19 July 2018

IJN Type 99 Air-tro-Air Bomb

Here are data sheets for the 'Mk.3' air-to-air bomb included in the new Fine Molds C5M2 kit - in case anyone was wondering! Although Fine Molds call this a Mark 3 bomb its correct designation was Type 99, No.3, Mk.3, Mod.1 bomb. The additional body fins were required for arming the clockwork tail fuse. 

The US Intel sheet says the additional body fins were to accelerate the bomb whilst the RAAF bomb disposal sheet says they were to slow down rotation, to stop the bomb bursting prematurely when it reached 1,000 rpm. The fuse burst the central charge and scattered white phosphorous filled steel pellets which ignited on contact with the air. 
The sheets also provide asdditional colour details. The Type 99 was an air-to-air bomb intended to be dropped over bomber formations per the Fine Molds box art but the sheets also imply an air-to-ground use. There are several photographs showing the resultant white 'jellyfish' type air burst (heading photo). 

Image credits:- National archives

Tuesday, 17 July 2018

It's Not That It's This! No It's Not! Etc.

Recently a friend of mine wrote that he was tired of The Great Zero Colour Discussion because people will continue to illustrate white Zeros regardless!  So true and I can understand his weariness. I thought about it on seeing that the latest Fine Molds Mitsubishi C5M2 kit (now available) recommends GSI (Gunze) Mr Color 35 IJN Gray Mitsubishi for the overall finish. Those stubborn purveyors of RAF Sky-like grey-green for the Zero will be disappointed because that paint is actually a rather bright, light, slightly blueish grey. 

The sample of Mr Color 35 paint that I measured in 2010 was a Munsell B - Blue - 4.7 B 6.4/0.8. Interestingly the Hobby Color version H61 IJN Gray measured at the same time as a Munsell GY - Green Yellow - 8.9 GY 6.2/0.7. I haven't tested more recent bottles but it appears that H61 in the new bottles is now closer in appearance to the light blue grey of 35.  Both Munsell values indicate very low blue colour saturation, or chromacity, from neutral grey. And the perception issue of low saturation blue or green undertones is well established. Some might perceive more green, others more blue.  

 In 1972 Matchbox suggested FS 37875!

That Munsell value for Mr Color 35 is interesting because both the closest FS 595 and RAL values are at exactly 1.69 in difference where < 2.0 = a close match. However they travel in slightly different directions. FS 36373 is a Munsell BG - Blue-Green, again of very low saturation, whilst RAL 7040 Fenstergrau (Window grey) is a low saturated PB - Purple-Blue. Pigments for 36373 are rutile (non-chalking) titanium dioxide (white), phthalo blue (red shade), natural raw umber (a dark, slightly greyish brown) and carbon black (blue shade). If you look at one and not the other, without looking at 35, they will mislead, despite their closeness.   

Zero replica from Eternal Zero (永遠の0 Eien no Zero) 2013

The idea of a light blue grey for the Zero seems very strong in Japan and appears to have made a comeback for modellers after popularity in the 1980s - although not with the makers of the Eternal Zero movie. The surface of the real paint does in some cases shift towards a light slightly blueish grey as it chalks* and degrades from glossy to dull matt. Most of the argument for light blueish grey as the original factory colour seems to be the emotional, personal choice kind (it does look smart on a Zero model) where the preferred colour is settled on before the evidence is marshalled and any inconvenient contradictory evidence is simply disregarded. 

Another idea promotes the grey-green colour, infamous as hairyokushoku (ash green colour), which in the minds of its adherents somewhat resembles RAF Sky, a cool, minty light green with a slight blueish undertone. Or maybe that's a cool light blue with a slight minty green undertone? Usually those arguments come with images lifted from online GSI or Tamiya colour charts or photos of models from Tamiya adverts (above), or rely on the semantics of colour descriptions - ambiguous at the best of times but even more so in Japanese. Rarely if ever do they incorporate physical analysis of the real paint - let alone the scientific measurement of it. Both ideas are more wishful thinking, if not a cult, than science.  And we are well into an era of post-revisionist revisionism where fad often defeats fact.

Tamiya XF-76, which in colour charts and their own model adverts often appears to support the minty grey-green brotherhood, is, as measured (and sorry to disappoint), a Munsell Y - Yellow.  It is slightly more greyish than the Zero factory paint - at a difference of only 3.67 - being something of a compromise between the original amber-grey appearance and a slightly oxidised and chalked appearance, or, alternatively, between  J3 leaning slightly towards ameiro and plain ol' J3. Note especially that it has an identical Munsell lightness value of 5.8. The pigments and their ratios in XF-76 paint are as follows:- Titanium Dioxide (white) 16.5%, Pigment Green 7 (Phthalo Green) 0.2%, Red organic 0.2%, Yellow organic 0.5% and Diatomaceous earth 0.7%. Pigment Green 7, although a strong tinting colour (despite being transparent), is known to darken and dull with long term exposure. The red and yellow organic pigments are not specified and there are several different types. Diatomaceous earth is a naturally occurring silecious sedimentary rock ground into a fine, off-white powder used as a filler and matting agent.  XF-76 is perhaps more representative of a moderately weathered aircraft in service for several months. Depending on lighting it can appear browner or greener, brighter or duller in online model images. 

Tamiya XF-14 (IJA Grey) is intended to represent the JAAF paint colour  # 1 Hairyokushoku (ash green colour) and is often suggested as the basis for the Zero colour in the erroneous belief that the Army and Navy paint colour standards were identical. It is actually further away from the original paint colour value than XF-76 and there is no comparison between the Army colour # 1 Hairyokushoku and the Kariki 117 ‘M’ series Hairyokushoku beyond the common name (# 1 vs M1 are at a difference of 20.1). The pigments in XF-14 are Titanium Dioxide 17.7%, Carbon black 0.1%, Pigment Blue 15 (Phthalo Blue - type unspecified) 0.1%, Pigment Green 7 0.1%, Red Organic 0.1% and Yellow organic 0.5%. XF-14 might be considered by some to provide a reasonable out of the bottle representation of 'scale colour' on a moderately weathered aircraft but it also lacks the distinctive amber undertone. Hopefully the relatively subtle differences in the Zero colour, IJA # 1, XF-76 and XF-14 will be apparent from this presentation.  

Ameiro ~ The Culprit

あめいろ 【飴色 · あめ色】noun:  amber;  yellowish-brown

'Ame iro' - a colour - has a quite different sense to 'ame' alone which also means rice jelly or candy. For most Japanese there is indeed a 'sense of transparency' in this term (which might have given rise to the idea of a clear varnish applied over grey paint, ambering as it aged) but it is also used to describe an opaque, solid colour.   So when the author of Kugiho 0266 described a grey colour leaning slightly towards amber/yellowish brown colour he was probably not describing a grey turned blue-green in appearance by the addition of clear yellow! 

If he wished to describe a light grey-green colour then it would have been far less ambiguous to refer simply to hairyokushoku for which the IJN Kariki 117 already had the established colour standard in the 'M' series. In fact one of the test aircraft (Yo-151) used in the camouflage trials recorded in the 0266 report was specially painted overall in M1, described in the report as pale green colour (see above). However that was not the colour described by the author throughout the rest of the report as gen'you (currently used) ameiro (amber colour) for the factory finish of the Zero.

Kariki 117 also had an established standard for blue-grey colours - the 'K' series described as kaiseishoku - but the author of 0266 referred to J3 ash/grey colour, any blueish undertone for which is unproven. The measured standard chip for J3 (and its successor colour 2-6) being a Munsell GY - Green Yellow of very low colour saturation. The slight greenish undertone of the chip could well be the result of age related yellowing and it is conceivable that J3 was originally a more neutral grey, but that does not substantially alter the effect of adding yellow-brown pigments to it.

Astonishingly, the extant paint appears exactly similar to the description grey colour leaning slightly towards amber colour and that description is absolutely consistent with the quantifiable attributes of the pigments and binder which it incorporates. But as my good friend observes, nothing will change and personally subjective ideas of how the colour ought to look will proliferate, as with all opinionated twaddle** on the internet. 

One last thing to always bear in mind if undecided. Ignoring evidence does not mean that it doesn't exist.

The polymer of the paint surface is degraded by a combination of heat, moisture and light resulting in a powdery, greyish-white pigment or patina forming on the surface. This type of degradation is exacerbated by certain types of white pigment, for example the anatase form of titanium dioxide, as well as by common paint fillers and extenders like China clay. Titanium dioxide is both a UV-activated oxidation catalyst and a UV absorber. Free radicals are formed at the surface and then oxidise the paint binder by photocatalytic degradation. This reduces the gloss and produces a friable layer on the surface of the paint film - "chalking". In effect the titanium dioxide pigment and any extender particles are being 'released' from the fractured binder to form a greyish-white powdery patina over the surface of the paint. That has the effect of dulling (de-saturating or washing out) and greying the appearance of the underlying colour and is often mistaken for colour fading. The powdery residue, like fine chalk dust but usually slightly greyish rather than pure white, will appear on the hand when rubbed across the paint surface. A diligent maintenance regime can reduce it but in certain environments it cannot be prevented. Many wartime colour photographs of aircraft reveal severe chalking of the paint surfaces, often misidentified as the 'real' colour.    

** Twaddle - trivial or foolish speech or writing; nonsense.18th c an alteration of twattle (1556), of unknown origin.

Image credits: Heading photoof Zero replica Martial heland via Wiki; Matchbox Zero box art © 1974 Lesney Products plc via Scalemates; A6M2 'Eternal Zero' replica via web; Tamiya 1/32 A6M2 image © 2003 Tamiya Inc.;Rendered colour chips © 2018 Aviation of Japan

Friday, 6 July 2018

Photo-Etchery ~ Ki-48 Sokei/Lily

I'm not a great fan of photo-etch. That's not due to any inherent faults with any of the vast amount of after market photo-etched detail enhancements now available. Rather it is indicative of my own inability. I have never been able to get on with using super glue. It always seems to end up where it shouldn't and not where it should, with precariously tilted panels and sidewalls which become an immoveable monument to inaccuracy and my clumsiness. The arrival of pre-painted photo-etch just increased the anxiety over the bending, fitting and glueing, with so much more exquisiteness to risk being ruined with clumsy fingers and old man eyesight. 

Recently Fred Boucher of Aeroscale kindly made me aware of the Platz photo-etch set M72X-07 designed for the Hasegawa 1/72 scale Ki-48 Sokei/Lily (above) which he has comprehensively reviewed here. The Hasegawa ex-Mania kit is due to re-appear in September as a 'Special Equipment Version' with the extended fuse rods in the nose of a rather plain-looking special attack aircraft (below). 

Fred's kindness and generosity then went further in providing me with a set. I won't reiterate the information in his review beyond confirming that the set is indeed exquisite. I like the fact that it is designed for an older but much esteemed kit which already has a pretty good interior to work on. Platz have a number of Japanese subject sets available in 1/72 scale, including the J1N Gekko (M72X-09),  G3M Nell (M72X-06), Ginga/Frances (M72X-05), G4M Betty (M72X-02), Ki-67 Peggy (M72X-03 - Aeroscale review here), A6M2 (M72X-01). The sets also cover a number of JASDF aircraft types and are 'projected' by NBM21 and made by Eduard. They can be ordered direct from Platz.

The panels in the Ki-48 set are a mid-toned olive green in the range FS 34130-34151. The modelling convention is for all Kawasaki cockpits to be painted in the yellow-brown colour attributed to the Ki-61 Hien or one of the convenience hobby paints derived from that belief, like RLM 79 (wrong!). Mr. Sunao Katabuchi posited in 2007 that Ki-61 cockpits were painted grey-green and that paint turned more brownish due to photo-chemical discoloration. The paint was sensitive to UV exposure as each component (oligomer or high polymer) was not consistently or effectively purified and contained many aromatic rings. Some extant artifacts in Japan as well as colour photographs appear to bear that out. Contemporaneous photographs taken inside the Ki-48 in service show a mixture of dark and light paints, perhaps the earlier dark-blue grey and later grey-green - or maybe yellow-brown. 

Interior paint colours examined on a Ki-48 wing section were shown at this blog in April 2013 here and were a light olive brown similar to FS 34201, with primers of dark green and dark yellow green. Without pigment analysis whether those colours represent colour shifts is open to speculation.    

When LAC I C Morton of the RAF examined Japanese aircraft at Meiktila in 1945 he reported: "In common with most Japanese aeroplanes seen, the three Oscar 2s had a yellowish-green finish all over the interior."* Morton tended to record any unusual or unexpected colours, so the fact that he examined Ki-48 aircraft in Burma and later Thailand without mentioning their interior colours might lead to a conclusion that they were also finished in a yellowish-green. The Platz paintwork is a little too dark and olive to perfectly fit that description but I doubt that the panels would look out of place with the rest of the interior finished in the yellow-green of the Japanese Army standard # 29 Ki midori iro or even the popular buff green hobby paints attributed to everything Nakajima.

The Ki-48 was popularly referred to by IJAAF personnel as 'Kyu-kyu sôkei' (九九双軽) - not 'Ninety-nine twin light' but 'Nine-nine twin light'. The Japanese abbreviation was - 'so' for sôhatsu (twin motored) and 'kei' for light(ly),  whereas in the West it might have been referred to as a 'light twin'. Morton reported on a Ki-48 examined at Don Muang, Siam in January 1946 (more details here) that the pilot had a 'first class forward view', that the landing speed was very high, with a tendency to instability at low speeds. In the air he thought it travelled fast, with 'a deep-throated roar from the two Kawasaki Type 2 radials'. He observed that all Japanese aircraft he had seen to date had made three-point landings and that Japanese pilots appeared to know their job thoroughly and had plenty of 'air sense'.    

* The Aeroplane Spotter, Vol.VII., No.156, 21 Feb 1946 pages 46-47.    

Image credits: Heading photo vintage postcard; Photo-etch © 2018 Platz Co. Ltd.; Box art © 2018 Hasegawa Corp; Colour chip © 2018 Aviation of Japan

Saturday, 30 June 2018

Moson Model Show ~ Japanese Subjects

Correspondent and contributor Marion Holly from USA has very kindly shared this report and his photographs of Japanese aircraft models displayed at the Moson Model Show held in April at Mosonmagyarovar in Hungary. In his own words then. . .

"The Moson Model Show (MMS) began 20 years ago as a scale model contest organized by the local club in the small Hungarian town of Mosonmagyarovar. Over time it has developed into one of the largest European scale modeling events. This year it was held during the weekend of April 20th through 22nd. 

"There were 2315 models entered in 66 contest categories (1749 models in 2017) by 881 modelers from 35 countries. I’ve always wanted to attend this show. Mosonmagyarovar is only 16 km from the border of my native Slovakia, but in 1996 I had settled in the USA so attending the show became slightly more “challenging”. 

"This year, about 3 weeks before the show I asked myself why wait any longer? It seemed a bit crazy to fly over the pond just for a weekend and the availability of flights was also of concern. But it all worked out and on the Friday morning of April 20th I landed in Vienna.

"Fast forward. It was all just amazing - beautiful summer weather, friendly, English-speaking town folks, peaceful spa town environment, great food, beer. And models of course. I’ve attended several big shows in the US, including Nationals, and abroad (UK, Mexico, Czech Republic) but the quality of the entries seen here was the best so far. As just one example of this, admiring some stunning detail work I accidentally discovered that I was in the junior section! 

"Having been interested in Japanese aviation all my modeling “career” I naturally focused on Japanese subjects and wanted to share pictures of them. There were not too many (relative to the total number of models on display), type selection was not too wide, whilst quality and presentation varied. 

"Artur Domanski’s 1/32 A6M3 Zero (posted at this blog on April 20th) was really nice. I just don’t think that a Zero with cowling removed looks that good. Also I’d debate the camouflage representation - field applied green flaking off as opposed to hasty overspray (in my opinion). 

"The weathering fad is alive and well with Japanese aircraft on top of the list with totally off colour shades and paint chipping to death, for example the 1/48 Seiran and Kyofu dioramas. 

"In two days of intense viewing I was only able to find one JASDF model, the F-104J (but lovely -ed.)! Lack of interest in this “theme” surprises me and I’m planning to return to it soon on this blog (Good! - ed). 

"Do visit the MMS website to see pictures of all the other models. My personal favourites are the 1/72 SM-79 Sparviero from the Italeri kit and a P2V-7 Neptune from the Hasegawa kit - just amazing detail work and finish."  

There appear to be approximately double the number of IJN subjects to IJA subjects. Most subjects being of well-known types except for the Army Type Otsu 1. With special thanks to Mario for sharing these photographs and his report from the show.

Image credits: All photos © 2018 Marion Holly