Sunday 22 August 2010

Golden Claude & Updates

The release of Special Hobby's 1/32nd A5M has rekindled interest in the "golden" finish of this iconic type. One of the best representations I have ever seen is Tom Cleaver's superb model, featured at the Modelling Madness website. To my mind it captures perfectly the anodised "Bento-box" appearance remembered by some eyewitnesses. My thanks to Tom Cleaver and Modelling Madness for kindly giving permission to show and link to it here.

Whether this finish was the result of a clear varnish applied over the natural metal or of using anodised aluminium in construction (or both) remains unconfirmed. In the USA the National Bureau of Standards had begun an investigation into the corrosion of light metal alloys used in aircraft as early as 1925 and this included various coated and uncoated surfaces, as well as the application of paints. During the 1930's the subject was explored in the UK and Germany with particular interest in aluminium pigmented paint coatings. A 1938 National Bureau of Standards report by Willard Mutchler (NACA No.633) concluded that the use of surface treated alloys together with aluminium-pigmented paint offered adequate protection in maritime conditions, provided the materials were not subject to frequent immersion.

In the UK around the same time Cellon had produced a grey primer paint with zinc oxide and yellow oxide combination additives which was found to be more effective than alumium-pigmented paints in resisting maritime corrosion. This grey paint was subsequently marketed as "Cerrux Grey". In Germany similar developments in coating protection were being explored with the introduction of corrosion-resistant grey paints in place of earlier alumium-pigmented paints. Germany had sold several aircraft types to Japan in the late 1930's and it is inconceivable that these protective coating developments had not been communicated within the proprietory or technical literature accompanying these exports.

Anodising had first been used on an industrial scale in 1923 to protect Duralumin seaplane parts from corrosion. This early chromic acid process was called the Bengough-Stuart process and was documented in British defence specification DEF STAN 03-24/3. Oxalic acid anodizing was first patented in Japan in 1923 so the process was known to the Japanese. It may have been considered an appropriate means of protecting aircraft in maritime environments where full immersion was not expected (as with carrier based aircraft). It is not unreasonable to expect that there may have been a certain amount of experimentation in developing corrosion-resistant finishes and coatings once this all-metal type entered service, so where we expect a single finish there may have been several throughout the service life of the type, including ultimately painting with the "special grey paint for light metals". 

The aspect of anodising that may be of interest in respect of Claude is that it can produce yellowish integral colours without dyes. Shades of colour can be in a range which includes pale yellow, gold, deep bronze, brown, grey, and black. Some advanced variations can produce a white coating with 80% reflectivity. The shade of colour produced is sensitive to variations in the metallurgy of the underlying alloy and cannot be reproduced consistently. Therefore where one looks in vain for signs of a transparent coating in photographs of the natural metal finish A5M this does not necessarily mean that the aircraft in question was not "yellowish" (or "gold") in appearance. Some modellers may agonise over interpreting or choosing a finish but my advice would be not to sweat it and if you prefer a straightforward natural metal then go for it.

Japanese Aircraft Interiors by Robert C Mikesh

I was astonished to read some particularly dismissive comments about this important work of reference at a well-known modelling forum. In addition to citing a lack of information on actual interior colours, one poster stated that he had "read it through and then sold it". Is it a novel?  I cannot imagine trying to retrieve the copious amounts of information in the book without having it to hand. It is a work of reference and in my view indispensable. The main issue with using it is in the various colour standards cited and the occasional inconsistency in matching them.

Another poster commented that as a reference it was "dated". Really? Does this mean that the precise photospectrometric colour measurements from actual aircraft recorded in the book have been superceded? Hmm. Perhaps a blurring of the difference between knowledge and opinion. I encountered this once myself, where Mr Mikesh's measured values (colour values measured from the actual extant paint surface with photospectrometric equipment) were disputed in favour of the appearance of colour photographs and the memory of a museum visit.

Well to get back to Mr Mikesh's "lack of information" here are some facts. The book covers 18 Army types and 28 Navy types, of which precise colour information is given for 11 (61%) and 19 (68%) types respectively. The grand total is precise colour information for 30 (65%) types out of 46. On the shelf within reach, permanent and in the absence of anything else, pretty useful I should say.

RS Models E15K "Norm"

From correspondent Jeff Groves I received these useful comments about the kit .

"I recently finished the Xotic-72 Norm kit, and had issues getting it to sit right on the beaching gear.  If you look at the few pictures of the actual aircraft available, the main wheels of the dolly sit right under the leading edge at the wing.  Despite adding weight to the main float (and even the propeller spinner!), there is just too much plastic aft of the wheels and the plane sits on it's tail.  My solution was to add an extension to the after part of the dolly to place some support aft, as some IJN dollies had this "double ended" configuration.

As seen in the screen shots, RS have provided a dolly which is designed to sit too far aft.  The rear support rests aft of the step on the main float on the model, it was actually just forward of the step.  Correcting this is not simply a matter of scooting the model back - the support heights are different, plus the model will sit on it's tail when the dolly is properly positioned.  The dolly alignment markings on the box art match the prototypes, but the dolly provided will not match these.  Without some change, the finished model will have the glaring error of the dolly markings on the float not lining up with the dolly.

Models should decide on an acceptable correction before beginning this build."

Thank you for this!

Computer Woes

Please bear with me. I have been experiencing some pretty horrendous problems recently which make connection difficult and unpredictable. Normal service will, I hope, be resumed soon!

Image Credits: Special Hobby A5M2b by Tom Cleaver via Modelling Madness, with permissions.


Bill Weckel said...


I think that I'm the one who made the comment about the Mikesh book being "dated".

I concede all of your points. Your blog post however, does not give the full context of the forum thread, which was in regards to the book's current street price. Naturally discussion turned to whether or not it was "worth" the large sums it currently sells for.

I've spoken with many modelers who have never laid eyes and hands on the book, and are under the false assumption that it is the final word in Japanese Aircraft Interior colors, and promises to answer any and every question definitively. As I'm sure you'll agree, this simply is not the case.

My specific comment was, if I recall correctly, in reply to a comment regarding it being reprinted. I stated my opinion that rather than a reprint, a revision is in order, given the amount of information that has come to light since it's publishing. I may also have said that I don't think that the book is a "must have" when one considers it's current asking price, and the fact that much (and maybe most) of the information contained within it, is freely available online at sites like J-Aircraft and your blog.

I certainly didn't intend to be disparaging. I own, and enjoy, a copy of the book.

Best regards,


Straggler 脱走兵 said...

Thanks for your input Bill.

I think the intrinsic "worth" of a published reference vs the availability of similar information on internet sites, especially forum sites, is debatable. All too often I see older published reference works dismissed or discredited as "outdated" on the basis of internet data which is presumed or promoted to be more up to date or superior. Very often it is quite difficult to establish:-

a) What exactly the new data is based on; and

b) Where it is to be found

The online "bites of the cherry" that can cumulatively discredit a published reference work are becoming increasingly difficult to quantify and assess. Statements are made, as at Hyperscale, and they are both bold and bald. I'm mindful of a step by step critique of a published reference by an established author in a specialist magazine. It ran to three pages and was a masterful demonstration of substance, specifying in every case where the work was in error. It was obviously a painstaking and time consuming exercise born of a passion for the subject and of considerable expertise.

To assess and accept your proposition that this work is dated, we would need to know where, how and why. The reference work in question is structured and "permanent", but you are asking us to accept on trust that there is newer and better information "out there." There may be, but hunting for it can be a formidable task and the information, when found, perhaps of unknown validity, especially when beset by long threads of divergent opinion.

Actually I think that currently it is indeed the "last word" on the subject! There is no other published reference on the subject (apart from Mr Mikesh's own earlier works) and for some of the reasons touched on above I would not set it in direct comparison or competition to the information available on the internet. rather I think it is an essential background and complimentary. I am also suspicious of those who seek to discredit authoritative works with generic criticism in order to give equal validity to what amounts only to their own opinions (and I am not suggesting that of you). This goes back to the substance of critique which is all too often today made in soundbites without showing the "working". Sometimes when I read these one-liners I think "Well why don't you write an article or book on it then?"

I don't think the context justifies the comments anyway. The value of a marketable commodity is based on the price someone is willing to pay for it and it is clear that the market does consider the book a "must have" - otherwise one would be able to buy it cheaply. Whether this urge to own the book is justified by its quality is hard to measure, but I suspect its status as a unique compilation on a very complex subject is what drives the value. It is not for you or I to say that such prospective purchasers are misguided as they represent probably considerable diversity in knowledge and motivation. The value or usefulness of the book to any one individual is almost impossible to assess but I won't be selling my copy anytime soon!

The transient nature of internet based information, especially on forum threads, is one reason the same or similar questions are asked, answered and argued about time and again. Sometimes the information is indirectly referenced, misquoted or misunderstand and modelling "myths" arise. There are also, in respect of some subjects, fairly well-entrenched armed camps, where dogma overwhelms debate. Set against all this, the fruits of Mr Mikesh's research in a published volume of such scope and detail look attractive and do not need to be considered definitive - especially given the uncertainties and complexities that surround the subject anyway.

The very long response is regretted but I fear I must fundamentally disagree with your points whilst fully understanding and respecting them.

Kind regards

Anonymous said...

Hi, Nick,
I think that the most contentious issue witn Mikesh's is the call for Ki.43 and 44 colour interiors. He proposes Aotake (the brilliant blue-green form) for Ki.43 and assumes it for the 44.
Otherwise, it is a seminal work which provides handy information, sometimes "final" and sometimes allowing you to make a good educated guess.

Bill Weckel said...

Thanks Nick. That was a nice, well-reasoned, and hard-to-argue-with reply. Not to drag things out, and just for a little further clarification, what I had in mind when I mentioned a revision based on "internet" sources, wasn't the content of threaded discussions, but more along the lines of contributions by researchers such as Jim Lansdale, and yourself. I'm absolutely confident that you would be able to add to and elaborate on the work, and you've proven that (at least to me) right here on your blog. The revised copy would be much better with these contributions. As for the inherent value, I suppose what I had in mind when I wrote that was seeing the book listed for well over a thousand US dollars, and thinking, no, I don't need to spend that much to build my Hasegawa Zero. ;-)

Thanks again,


Bill Weckel said...


I'm actually building the Classic Airframes 1/48 Claude, and although I'm not at the point where I need to make a paint decision, I have to admit that I'm one of the modelers "agonizing" over the decision. I *want* a gold Claude, and your "blessing" on going forward with it has sealed my decision.



Dal Gavan said...

G'day, Nick.

I've just spent an interesting hour reading your blog- though I admit that a lot of it passed well over my head. My interest in Japanese WWII aircraft is just a general one, as I'm mainly interested in RAAF subjects, but even I can appreciate the work you've done. I would like to thank you for sharing your work with us.
Dal Gavan

Young Ian said...

Thanks for the intriguing pieces of history re protective coatings. I have a couple of marginally relevant comments:
Back in 1995 I drove down to the Experimental Aircraft Association's fly-in in Lakeland, Florida. Anyone with an interest in aviation would find this event a treat, if not a revelation. A couple of warbird collectors had acquired ex-Chinese Yak-oid trainers (I don't know their exact designation). They were well-used, but sported garish yellow-green anodized finishes. One has no trouble distinguishing that surface from paint! So there's certainly precedent for overall anodizing of military aircraft. I have also read that when Convair was developing its
four-engined jet airliner, the 880, serious consideration was given to treating the exteriors with gold-colored anodizing, and marketing the 880s as "Golden Arrows."