Jump to content

BLUE PRIMER instead of Zinc Chromate or Interior Green on a Vultee tra


Recommended Posts

[This thread is the same as in the "Classic Aviation" section, sorry, it's a "prop" AND a "classical" aircraft :bandhead2: ]

Hello,

a friend is restoring a real Vultee BT-13A.

I am very surprised by all the inner surfaces.

They are BLUE.

Not Zinc Chromate (yellow) nor Interior Green (green), nor Salmon Pink like on the early Birdcage, but BLUE.

Was it an usual color for the primer or is it an exception ????

I have never seen a scale model with this color. Are modelers ignore it ?

Here a sample :

b67bc7e7dcdc44dbef992f2161db90c7.jpg

cdd7b29ecf1a7727cd8dc5c12adf4c1a.jpg

1754920b6793b507f05541b9d0e3a055.jpg

Link to post
Share on other sites

OK, a little answer here : http://www.nationmaster.com/encyclopedia/Z...-primer-(paint)

The protective effect of chromate coatings on zinc is indicated by color, progressing from clear/blue to yellow, gold, olive drab and black. Darker coatings generally provide more corrosion resistance. Chromate conversion coatings are common on everyday items such as hardware and tools and usually have a distinctive yellow color.

It seems to be Zinc Chromate in its "blue" phase.

Not very usual, but possible.

Jérôme

Link to post
Share on other sites

Curtiss used a translucent blue anti-corrosion "shop coat" on P-40s during assembly, but it was usually either later overpainted with Zinc Chromate or stripped off. This is the first I've seen of an opaque blue primer. I wonder if this bird originally had a blue fuselage and yellow wings, and the fuselage was simply painted blue inside and out during assembly. It's amazing how stuff like this continues to come to light after all these years.

I'd suggest contacting Dana Bell. He may not have any answers, but he'd sure be interested!

As an aside, I remember reading once that when Ford was building B-24s, some genius suggested that that they use different pastel shades for the interiors, and change the colors every production block. Not surprisingly, the Army Air Force rejected the idea.

SN

Edited by Steve N
Link to post
Share on other sites

I have red an article here : http://www.colorserver.net/history/history-zinc-chromate.htm

It is said :

Untinted and Tinted Primer

US Erection & Maintenance instructions of the period often refer to "untinted" and "tinted" primer to describe raw Zinc Chromate primer and the same primer tinted with black. While black was the intended additional pigment, the instructions did not specify the formulation of colors. Therefore it is not unlikely that manufacturers felt free to pick substitute pigments when needed. A Navy memo from 1942 goes even further and recommends using Indian Red (you can see it in the back on the first picture), lamp black, or any other suitable indicator to use with a second coat of Zinc Chromate primer to distinguish between single- and double-coated surfaces. In the light of this memo, Vought's Salmon pink was also simply tinted primer.

It seems to be very informal, depending of the constructor, the period, etc...

Jérôme

Edited by Jérome the frenchie
Link to post
Share on other sites

I posted those photos over on a warbird forum. One gentleman responded that he restored a pre-war BT-13A, and found the same blue paint inside and out. I think (just my personal opinion) that the fuselage was painted the standard USAAF blue inside and out prior to final assembly, but the paint was stripped off the outside later in the plane's career. You'll notice that the same blue is on the outside under the tail and horizontal stab fillets, lending credence to the idea that it was stripped down without being disassembled.

SN

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...