Seafury1 wrote:What year, as close as possible, did they switch from A; clear cad to gold, B; from clear anodize (or the gray anodize) to blue on AN fittings?
War time fuel line, the red line ID is painted and the AN Fitting is clear anodize. I know the Dottie Mae had some blue fittings, but no gold cad.
First, all my data is backed up from original blueprints and AN drawings that go back to the 1920's to the 1950's.
OK, Cadmium is only silver looking in its raw state. Class 1 refered to as ClassI is natural silver color. There are 2 variations on this, left raw and clear alodined. The first if left raw will start the corrosion process sooner that the clear alodine, which is done for just that reason. If you see hardware that is a dull gray color chances are if its new then it was not cleared. What is sooner, depends wildly on the environment, on a ship at sea, FAST, in a temp controlled hangar in Calif, probably not my life time.
If you want that gold color you still do the above, then use a colored dye, like Gold alodine for example. Technically its dyed with just a dye but you can use alodine.
There is no set date that I can come up with that is the magic day to start using ClassII(gold). I know for a fact from several Corsairs that ClassII was used during the 1945 time frame during manufacturing. We know this because several of us have removed hardware from deep within, painted over that was gold. Also it might take a few years for one vendor to go thru all the ClassI where another one might have ordered smaller amounts and used it up quicker. Who knows!
Anodizing is clear, period! Now before you say anything you must know how its done(I do it here in my shop as well as CAD plating, have been for 10 years).
Anodizing is the "growing" of a chemical surface on aluminum. Its actually done exactly opposite as Cad plating, except it uses ONLY chemicals. It looks like a Bee's honey comb under a microscope. AFTER the anodizing is done, it is then soaked in a dye of your choice. That dye fills the pores. Then it MUST BE SEALED to retain the dye. You do this by simply hanging the part over a steam of distilled water for a time frame. The combs just glaze over and curl up, sealing the dye in the anodized pores you "grew" on the surface. If the item looks Grey, it might just simply be natural aluminum looking, i.e. no dye. SeaFury1 your picture could have been blue at one time, its VERY LIKLY that the blue dye is simply gone.
You can check the integrity of an anodized part, put a volt meter on the item, it will NOT conduct electricity. If it does the anodized surface has broken down. This is usually seen from the dye either missing or very very faded. Once the anodizing is gone, it can start corroding.
As for the time frame of Blue AN fittings, I can tell you the AN "Print" says it was approved in 3 Feb 1941 for an AN815 Union. You would have to look deeper on the print for the Proc Spec to describe the finishes and other info. In this case it is MIL-F-5509. This print I have was last revised 1 June 1954. After that I dont know or care as I am stuck in the 1940's !
Which brings us to another subject, who used what when. The US NAVY required AN fitings as early as 1942. There is a slight variation of AN fittings from 1942 to 1955, but as far as I can find it was mostly machining variations, the prints dont really change the basic measurements.
So is it ARMY or NAVY, seems they didnt really do the same thing most of the time. Kinda like ARMY vs NAVY football. Need I say more!!
So the question is do you use Steel, brass or aluminum AC or AN fittings on a restoration, are they CadI, grey, blue or black...
Do you use ClassI or ClassII hardware...
Do you use SS clamps or steel, again, plated ClassI or ClassII...
and on and on...
DEPENDS ON TO MANY VARIABLES! I have lost countless hours of sleep trying to decide on things like this.
Last edited by t28pilot
on Fri Jan 02, 2009 10:53 pm, edited 1 time in total.