Interesting issue in rotary tumbler
Good morning gents,
I have been using one of the small rotary tumblers with pins, dawn, and food grade citric for some time now. I believe my pins have worn out. Not rounded or flattened, but they are bleeding the nickel out of the pins themselves.
Last few times I used it I noticed the brass was just not coming clean and had a dingey dark color to it. Now this is uniform and they look clean, just dingey. So, I had a batch of 5.56 that I let go all night. Wow and yuck. Lots of black goop came out of the tumbler and the brass looks almost nickel washed.
This media is most definitely the cheapest I could find and fairly well used. I've had it for at least 3 years and used it for hundred if not a thousand cycles. I have the brass in the tumbler now minus pins to see if I can get it cleaned up.
Has anyone seen this before? What the heck is going on here? My only thought is the pins are degrading. The brass was not that dirty before it went in.