In preparation for my SEPT / OCT 1/48 builds I would like to know what a B-29 fuslage was made of.
I only use ALCLAD.
I will be using the PYN-up decals on my B-29, "The Outlaw" (Jane Russell) artwork.

Are you asking what the model would be made of, or are you asking what the structural metal was in the real aircraft?

If it's the real aircraft, then you would have had aluminum skin over steel semi-monoque construction; similar to the B-17 Fortress, and you can see a lot of that in most pictures online.

BTW, Jane Russell is a very good choice for a pin-up...!

what the structural metal was in the real aircraft

Thanks James. I wrote that ? as I was heading off to sleep. However you answered what I thought.

You're welcome...

Marc,

B-29 models are a fascinating beast to paint! You may be familiar with his image:

Note the band over the fuselage between the wings that is so much lighter? Note the darker strips inboard of the wingtips? Note that the wing structure between those two areas appears much duller, compared to the fuselage, than the trailing half of the wings over the flaps.

Why is this? It is how light reflects from the surface: ambient; diffuse; emissive; specular (I probably mis-used those terms.)

It was explained to me from an A&P (Airframe & Powerplant mechanic) that when the light is right, the 'grain' of the American 75ST and 24ST aluminum alloy will reflect a clear sky differently: NMF silver, silver-gray, bluish-silver, eye-searing white-silver. Same metal, different 'colors.'

B-29 wings were assembled as a single main piece extending to just beyond the outboard engine nacelles; then the leading and trailing edges were added. There is an assembly line photo of a B-29 broken down into its major sub-assemblies: nose to pressure bulkhead at the forward bomb bay; center fuselage section; rear fuselage with empennage from pressure bulkhead aft of bomb bay; nacelles; outer wings beginning at the ailerons. So as light reflects from the skin a variety of factors create what appear to be different colored panels. And I don't know for certain but perhaps the B-29 wing center section was painted with a smoothing coat of glossy aluminum paint like the P-51's wings were.

One other thing to consider is that unprotected aluminum will oxidize into a dull gray. Back in 1993 or so I visited NASM Silver Hill restoration facility and actually got to touch - with permission- Enola Gay. (They were trying different skin polish/protectants and encouraged the unwashed to slap our greasy palms upon the artifact.) Even though Enola Gay had been in protected storage for years her skin was not gleaming like when she was newer.

What's my experience? When I built Monogram's 1/48 B-29 long ago I examined Shep Paine's insert and B-29 books. I mixed up seven different 'silvers,' chrome, silver, aluminum, tinted with blue, with gray... I probably overdid it back then yet she was impressive.



It is a wonderful time to be a modeler! You shall have enough ALCAD to create the most intricate B-29 finish. I love Floquil and found years ago that a NMF of Silver, Old Silver, and Platinum Mist looks great as is, plus can be buffed to different effects.

BTW, ignore CAF's Fifi which is overpainted with protective aluminum paint.

Here's a color film from WW2 that has some scenes of what I have attempted to impart: http://beforeitsnews.com/motor-junkies/2013/07/color-film-of-a-b-29-flight-with-p-51-escorts-on-a-run-to-bomb-japan-2472640.html

I hope this is useful.

Since that area is where the fuel tanks live, it's a good bet that it's coated in Coroguard finish. Boeing has been using this on fuel tank wing spar boxes for decades. It's a matte greyish-silver colour with no "official" standard, since each batch is mixed up on site when it's applied. It often looks different depending on how the light hits it. For example, look at this aircraft: Two different colours on two different wings, same Coroguard on both. Whatever looks good to you will be correct

An alternative to Alclad is to use foil. I'm not suggesting that for your B-29, but if you read through this build you'll see a great demonstration of the grain Fred was talking about, and how this particular modeller achieves that using real metal.

The reason why the center protion reflects light differently is that this area is made of thicker MACHINED metal rather than rolled sheet metal, as on all other WWII aircrafts...

This was unique at the time to the B-29: The difference in colour is due to the fact that machined metal has a machine-generated unidirectional abrasion grain that would be tough to polish out: The direction of the grain will catch the light different depending on light angle: Thus it can look lighter or darker depending on light angle or orientation.

Some wartime B-29s were highly buffed, and I don"t know how it would affect the center portions. The different shade was not paint but could look like it on a model, though beyond 1:72 the appearance could be hard to nail down...

Gaston

Sorry for the late reply of thanks. Life got in the way.

Frederick - Thanks for the GREAT post. A lot to consider and I see patience will be tested.

Jessica - Thank you for chiming in. Not a fan of foil and Alclad is a wonder paint for me.

Gaston - Appreciate the input.

Gaston,

Thank you. That sheds light (Pardon the pun.) on a question I've had for a looooonnng time.

We were always told that the difference in texture was due to those areas being made of a different metal (magnesium?)

The engine crankcases were made from magnesium but the aircraft predominantly from aluminium alloys. 24ST is the one that gets the most mention which is Alclad and so was probably what was used for the skin.

Alclad is a sandwich of pure aluminum and Duralumin. The surface of pure aluminium quickly oxidizes and the aluminium oxide forms a thin layer that protects the aluminium from further corrosion. Aluminium is, however, not very strong.

Duralumin is an alloy of aluminium with aprrox 4.5% copper and smaller amounts of manganese and magnesium. Duralumin is harder and stronger than aluminium so thnner sheets can be used, but it does not inherit the corrosion resistance of aluminium.

Alclad is made by pressing sheets of the hot metal through rollers so that the layers bond together. The outer layers of pure aluminium provide corrosion resistance while the inner Duralumin provides strength.

Similar to a Mustang, the central panels on the wings were painted with aluminium lacquer.

Which is that Coroguard finish to which I referred earlier. It's made of a clear lacquer base to which is added aluminium powder by weight and mixed right before application.

Corroguard is a two-pack epoxy coating not a lacquer.