Diamond Labs Hurricane Baked?

[BiNumber3]

So I had bought a used diamond labs hurricane valve back a month ago, it's anno was faded to a lighter shade. I decided to sand n polish it, but once i did, noticed the aluminum underneath was dark, like gunmetal gray.
It is aluminum as far as I can tell, lighter than a classic back half and it was anno'ed, so no issues on that.

So, question is, what can cause aluminum to change color all the way through (possible result of baking?)? or is there aluminum out there that doesnt become a really light silvery color when polished?

Pics might be comin soon, bro lost his camera so might needa borrow one

[Chrome]

Are you sure it isn't titanium?

[BiNumber3]

did they make em in titanium?? now that u mention it the color looks like my old ti boomstick, ill check density
and can titanium be annoed?

edit: seems density is around 4.3 g/cm3, usin a pretty accurate scale n a horribly inaccurate measuring cup

so, not quite up to ti density, unless it's an alloy with high titanium content?

[snoopay700]

did they make em in titanium?? now that u mention it the color looks like my old ti boomstick, ill check density
and can titanium be annoed?

edit: seems density is around 4.3 g/cm3, usin a pretty accurate scale n a horribly inaccurate measuring cup

so, not quite up to ti density, unless it's an alloy with high titanium content?
It would only be aluminum, only ti ones were classic valves. It could have been baked, seeing as that was a new trend for a while.

[BiNumber3]

there were ti classic valves? interesting

baking wont affect density tho, ive tested the density of an rt valve back n that turned out pretty accurate, this vlave back however is nowhere near the density of regular aluminum, n i doubt even the highest grade aluminum would be this dense

did any other companies make valve backs? i know shocktech did, but heard those were aluminum as well

[Ando]

If it looks like a dark gray color then yes it's been "baked" aka age-harden. I work with this stuff all the time. Majority of our aircraft aluminum is baked. Depending where it's going to be used or placed. If it's not done properly you can actually burn it like you would a cake and it will crumble.

The darkening is from too much or too little silicon to magnesium in the metal or something, don't quote me cause it's been years since I read up on this BS. It's a type of oxidation. I'll do some searching and kick ya some knowledge here in a few seconds. ;)

[BiNumber3]

hmm, so am i measuring its density wrong? it's 2.7oz, or 76.5 grams, and 18 ml give or take, so density should be 4.25g/cm3

[Ando]

Anodic Oxidation is what it's called.

http://iadr.confex.com/iadr/china04/preliminaryprogram/abstract_49715.htm

They did testing on titanium but its the same same with aluminum.

I've seen stuff come out silver, gun metal to almost white sometimes, just depends on the metals mixture of the aluminum. (I think) :confused:

[BiNumber3]

would baking be able to cause the aluminum to change color throughout tho? ive sanded it quite a bit but it seems the coloration might be through out the metal.
any oxidation should only affect the outermost layers

[Ando]

Age hardening will do that. There's nothing wrong with the metal. Read up on it. It's like the final step of hardening metals. I think they actually call it a heat tint.

Look up Precipitation hardening.

Edit: Actually I'm the one that's screwed up. It keeps the metal from oxidizing not what I said in my last post.

Edit: Second to last post.

[snoopay700]

He's talking about the trend of putting it in your oven to change the anno, or baking. You could have measured the density wrong, but i know the hurricanes were supposed to be alum.

And as for the ti classic valves:
http://www.automags.org/forums/showthread.php?t=211583

[BiNumber3]

hmm, tried the magnet test, but like mentioned the magnet doesnt even stick to the stainless parts.

i rubbed the part against some glass, it left a really light mark

so.....

my stainless back weighed 5 oz whereas this one weighs 2.7oz, anyone have a hurricane or shocktech they can weigh?

edit: and it's titanium, did density n the spark test...

[snoopay700]

That's odd, i didn't think that hurricanes were titanium...

[Chrome]

I thought I remembered from a thread a little while back in the BST that some of the DL backs were titanium, some were aluminum, and Shocktech also made a run of aluminum ones.

http://www.automags.org/forums/showthread.php?t=243210&highlight=regulator