Pink brass

No, it's more than that. 5% citric acid was the old Frankford Arsenal brass cleaning formula before the military stopped removing forming process oxides from their cases.
Click to expand...

I would have to go dig for the formula, I do not believe it would be worth the effort but the formula used long before the Internet was referred to as pickling, I have no ideal what would happen if I asked a pharmacist to but the ingredients together.

Time is a factor.

F. Guffey
 
Pickling is still done with sulfuric acid as a prep for nickel plating. Citric acid doesn't seem to react with cuprous (red) copper oxide as sulfuric and nitric acid will, and it takes some more time on cupric (black) copper oxide than it does on verdigris (copper carbonate here, but also copper chloride near salt water). So the pinkish hue left after using citric acid to clean a heavily tarnished case has to be polished off if you want it removed. You can see it in the post-cleaning photo below.

attachment.php
 
The black cases I was referring to had to do with the finish product, had to do with what I call the worst of cases.

Orang/pink etc. It is a given when cleaning cases in vinegar. I have a limit if 15 minutes, I could reduce the time by stirring the cases but when I started I tested a a few cases. I started by leaving the cases in vinegar for 2 days, the cases started to disappear; I cut the time back to 30 minutes and found the cases turned orange/pink etc., it was about that time I settled on 15 minutes, and I rinsed the cases in boiling water it seems there are some chemicals that have an affinity to some metals and boiling the cases to rinse cut down on tumbling time.

F. Guffey
 
You must log in or register to reply here.
Back
Top