My Lake City brass turned Silver?

[kealil]

Hello All,

I had an interesting occurrence today. I was tumbling some Lake City brass to get it ready for loading. I use wet tumbling with Stainless Steel pins, Dawn, and Lemi-Shine.

I normally tumble my brass for about an hour just to get it really shiny. I forgot about this batch, and it tumbled for somewhere near 6 hours. When I dumped the brass, I discovered that every single piece of brass had turned silver! Not just splotches of silver or anything like that, they turned completely silver in color inside and out. It almost looks like dull nickel plating.

I will add pictures when I get home but does anyone have an idea of what happened? This is just so weird since none of my other LC brass did this to me.

 

[skizzums]

I think you probably had some nickel plated cases mixed with the others. I don't ss tumble, bit I've heard this before. They'll be fine to shoot

 

[kealil]

Hello Skizzums,

Normally I would agree, and maybe you are right, but I bought the LC 556 brass in a bulk 1k pack. All were brass colored before the wash. These 150 cases were also brass colored before the wash. Every other batch of brass from the tumbler came out shiny, bright and gold but this one batch which was left longer came out nickel colored.

So I guess this leads me to my first question: Does Lake City 556 brass even come as nickel plated? And if so, why would it be brass colored beforehand? Maybe I am just not knowledgeable enough about the military brass.

 

[skizzums]

I have lots of nickel plates LC. Not sure if that's what happened, since a nickel plate would stand out like a sore thumb. But my guess seems to be the best, since its the only one you got

 

[Unclenick]

Have you used or pre-tumbled your stainless pins enough to be sure any SS dust is gone from them?

It sounds like maybe you've created white brass at the surface of the cases, which is low copper, high zinc, in one of its several incarnations. It's also possible, given all the shades of blue an purple that some zinc oxides have, that you just have oxide discoloring that occurred after the Lemishine was used up and that happens to mix with the metal coloring to appear white. Several odd possibilities there.

Dissolve a tablespoon of Lemishine in a juice glass full of hot tap water. Drop one of your silver cases in and check it in half an hour too see if the color changed back to brass.